Patent Publication Number: US-2023157410-A1

Title: Foot Support Systems Including Fluid Movement Controllers and Adjustable Foot Support Pressure

Description:
RELATED APPLICATION DATA 
     This application is a U.S. Non-Provisional application and claims priority benefits based on U.S. Provisional Pat. Appln. No. 63/282,943 filed Nov. 24, 2021 and entitled “Foot Support Systems Including Fluid Movement Controllers and Adjustable Foot Support Pressure.” U.S. Provisional Pat. Appln. No. 63/282,943 is entirely incorporated herein by reference. 
     Aspects and features of this technology may be used in conjunction with the systems and methods described in any one or more of:
     (a) U.S. Provisional Pat. Appln. No. 63/031,395 filed May 28, 2020;   (b) U.S. Provisional Pat. Appln. No. 63/031,413 filed May 28, 2020;   (c) U.S. Provisional Pat. Appln. No. 63/031,433 filed May 28, 2020;   (d) U.S. Provisional Pat. Appln. No. 63/031,444 filed May 28, 2020;   (e) U.S. Provisional Pat. Appln. No. 63/031,455 filed May 28, 2020;   (f) U.S. Provisional Pat. Appln. No. 63/031,468 filed May 28, 2020;   (g) U.S. Provisional Pat. Appln. No. 63/031,482 filed May 28, 2020;   (h) U.S. Provisional Pat. Appln. No. 63/031,423 filed May 28, 2020;   (i) U.S. Provisional Pat. Appln. No. 63/031,429 filed May 28, 2020;   (j) U.S. Provisional Pat. Appln. No. 63/031,441 filed May 28, 2020;   (k) U.S. Provisional Pat. Appln. No. 63/031,451 filed May 28, 2020;   (l) U.S. Provisional Pat. Appln. No. 63/031,460 filed May 28, 2020;   (m) U.S. Provisional Pat. Appln. No. 63/031,471 filed May 28, 2020;   (n) U.S. Patent Appln. No. 17/333,309 filed May 28, 2021;   (o) U.S. Patent Appln. No. 17/333,333 filed May 28, 2021;   (p) U.S. Patent Appln. No. 17/333,493 filed May 28, 2021;   (q) U.S. Patent Appln. No. 17/333,555 filed May 28, 2021;   (r) U.S. Patent Appln. No. 17/333,630 filed May 28, 2021;   (s) U.S. Patent Appln. No. 17/333,683 filed May 28, 2021;   (t) U.S. Patent Appln. No. 17/333,735 filed May 28, 2021;   (u) U.S. Patent Appln. No. 17/333,785 filed May 28, 2021;   (v) U.S. Patent Appln. No. 17/333,867 filed May 28, 2021;   (w) U.S. Patent Appln. No. 17/333,919 filed May 28, 2021;   (x) U.S. Patent Appln. No. 17/333,974 filed May 28, 2021;   (y) U.S. Patent Appln. No. 17/334,015 filed May 28, 2021; and   (z) U.S. Patent Appln. No. 17/334,049 filed May 28, 2021.   
 Each of U.S. Provisional Pat. Appln. Nos. 63/031,395, 63/031,413, 63/031,433, 63/031,444, 63/031,455, 63/031,468, 63/031,482, 63/031,423, 63/031,429, 63/031,441, 63/031,451, 63/031,460, and 63/031,471 and each of U.S. Patent Appln. Nos. 17/333,309, 17/333,333, 17/333,493, 17/333,555, 17/333,630, 17/333,683, 17/333,735, 17/333,785, 17/333,867, 17/333,919, 17/333,974, 17/334,015, and 17/334,049 is entirely incorporated herein by reference.
     Aspects and features of this technology may be used in conjunction with the systems and methods described in any one or more of:
     (a) U.S. Provisional Pat. Appln. No. 62/463,859 filed Feb. 27, 2017;   (b) U.S. Provisional Pat. Appln. No. 62/463,892 filed Feb. 27, 2017;   (c) U.S. Provisional Pat. Appln. No. 62/547,941 filed Aug. 21, 2017;   (d) U.S. Provisional Pat. Appln. No. 62/678,635 filed May 31, 2018;   (e) U.S. Provisional Pat. Appln. No. 62/678,662 filed May 31, 2018;   (f) U.S. Provisional Pat. Appln. No. 62/772,786 filed Nov. 29, 2018;   (g) U.S. Provisional Pat. Appln. No. 62/850,140 filed May 20, 2019;   (h) U.S. Pat. Appln. No. 16/488,623 filed Aug. 26, 2019;   (i) U.S. Pat. Appln. No. 16/488,626 filed Aug. 26, 2019;   (j) U.S. Pat. Appln. No. 16/105,170 filed Aug. 20, 2018;   (k) U.S. Pat. Appln. No. 16/425,331 filed May 29, 2019;   (l) U.S. Pat. Appln. No. 16/425,356 filed May 29, 2018;   (m) U.S. Pat. Appln. No. 16/698,138 filed Nov. 27, 2019;   (n) U.S. Pat. Appln. No. 16/878,342 filed May 19, 2020; and   (o) U.S. Provisional Pat. Appln. No. 63/273,640 filed Oct. 29, 2021.   
 Each of U.S. Provisional Pat. Appln. No. 62/463,859, U.S. Provisional Pat. Appln. No. 62/463,892, U.S. Provisional Pat. Appln. No. 62/547,941, U.S. Provisional Pat. Appln. No. 62/678,635, U.S. Provisional Pat. Appln. No. 62/678,662, U.S. Provisional Pat. Appln. No. 62/772,786, U.S. Provisional Pat. Appln. No. 62/850,140, U.S. Pat. Appln. No. 16/488,623, U.S. Pat. Appln. No. 16/488,626, U.S. Pat. Appln. No. 16/105,170, U.S. Pat. Appln. No. 16/425,331, U.S. Pat. Appln. No. 16/425,356, U.S. Pat. Appln. No. 16/698,138, U.S. Pat. Appln. No. 16/878,342, and U.S. Provisional Pat. Appln. No. 63/273,640 is entirely incorporated herein by reference.
    
    
     FIELD OF THE INVENTION 
     The present invention relates to fluid flow control systems and/or foot support systems in the field of footwear or other foot-receiving devices. At least some aspects of the present invention pertain to fluid distributors, fluid transfer systems, sole structures, fluid flow control systems, foot support systems, articles of footwear, and/or other foot-receiving devices that include components (e.g., a manifold, a fluid transfer system, an electronic controller, etc.) for selectively moving fluid within, into, and/or out of the sole structure (or other foot-supporting member) and/or article of footwear (or other foot-receiving device). Using such systems, fluid pressure (e.g., foot support pressure, fluid container pressure) in one or more fluid filled bladders (e.g., foot support bladder(s)) and/or one or more fluid reservoirs and/or containers included in the overall system may be changed and controlled. 
     BACKGROUND 
     Conventional articles of athletic footwear include two primary elements, an upper and a sole structure. The upper may provide a covering for the foot that securely receives and positions the foot with respect to the sole structure. In addition, the upper may have a configuration that protects the foot and provides ventilation, thereby cooling the foot and removing perspiration. The sole structure may be secured to a lower surface of the upper and generally is positioned between the foot and any contact surface. In addition to attenuating ground reaction forces and absorbing energy, the sole structure may provide traction and control potentially harmful foot motion, such as over pronation. 
     The upper forms a void on the interior of the footwear for receiving the foot. The void has the general shape of the foot, and access to the void is provided at an ankle opening. Accordingly, the upper extends over the instep and toe areas of the foot, along the medial and lateral sides of the foot, and around the heel area of the foot. A lacing system often is incorporated into the upper to allow users to selectively change the size of the ankle opening and to permit the user to modify certain dimensions of the upper, particularly girth, to accommodate feet with varying proportions. In addition, the upper may include a tongue that extends under the lacing system to enhance the comfort of the footwear (e.g., to modulate pressure applied to the foot by the laces). The upper also may include a heel counter to limit or control movement of the heel. 
     “Footwear,” as that term is used herein, means any type of wearing apparel for the feet, and this term includes, but is not limited to: all types of shoes, boots, sneakers, sandals, thongs, flip-flops, mules, scuffs, slippers, sport-specific shoes (such as golf shoes, tennis shoes, baseball cleats, soccer or football cleats, ski boots, basketball shoes, cross training shoes, etc.), and the like. “Foot-receiving device,” as that term is used herein, means any device into which a user places at least some portion of his or her foot. In addition to all types of “footwear,” foot-receiving devices include, but are not limited to: bindings and other devices for securing feet in snow skis, cross country skis, water skis, snowboards, and the like; bindings, clips, or other devices for securing feet in pedals for use with bicycles, exercise equipment, and the like; bindings, clips, or other devices for receiving feet during play of video games or other games; and the like. “Foot-receiving devices” may include: (a) one or more “foot-covering members” (e.g., akin to footwear upper components) that help position the foot with respect to other components or structures, and (b) one or more “foot-supporting members” (e.g., akin to footwear sole structure components) that support at least some portion(s) of a plantar surface of a user’s foot. “Foot-supporting members” may include components for and/or functioning as midsoles and/or outsoles for articles of footwear (or components providing corresponding functions in non-footwear type foot-receiving devices). 
     A “manifold” as used herein means a component having a surface or housing that defines or supports one or more ports that allow a fluid (e.g., gas or liquid) to enter and/or exit the component. A “port” as used herein means an opening through a wall of a component that allows fluid (e.g., gas or liquid) to pass through from one side of the opening to the other. Optionally, a “port” may include a connector structure, e.g., for engaging another object, such as a fluid line, another connector, or the like. When including a connector structure, a “port” may form, for example, a male connector structure, a female connector structure, or an abutting surface connecting structure. Object(s) connected to a “port” may be fixedly connected or releasably connected. Additionally or alternatively, object(s) connected to a port may be fixed to or releasably connected to interior surfaces of the opening through the wall of the component through which the opening is defined. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The following Detailed Description will be better understood when considered in conjunction with the accompanying drawings in which like reference numerals refer to the same or similar elements in all of the various views in which that reference number appears. 
         FIG.  1 - 2 B  provide views of articles of footwear and components thereof in accordance with some examples of this technology; 
         FIGS.  3 A- 3 D  provide views of pumping systems that may be used in accordance with some examples of this technology; 
         FIGS.  4 A and  4 B  provide views of foot support systems and components thereof in accordance with some examples of this technology; 
         FIGS.  5 A- 5 F  provide views explaining several example operational states in accordance with some examples of this technology; 
         FIGS.  6 - 9    provide views of incorporation of fluid distributors into articles of footwear in accordance with some examples of this technology; 
         FIG.  10    schematically illustrates features of the layout and engagement of component parts in accordance with some examples of this technology; 
         FIGS.  11 A- 15 G  illustrate features of engaging fluid distributors with articles of footwear in accordance with some examples of this technology; 
         FIGS.  16 A- 21 D  illustrate features of battery charging systems that may be used in accordance with some examples of this technology; 
         FIGS.  22 A- 22 E  illustrate features of example user input systems in accordance with some examples of this technology; 
         FIGS.  23  and  24    illustrate schematic diagrams and component positioning features in accordance with some examples of this technology; 
         FIG.  25    illustrates examples of communications in systems and methods in accordance with some examples of this technology; 
         FIG.  26 A -29 illustrate components of a valve stem based fluid transfer system in accordance with some examples of this technology; 
         FIGS.  30 A- 30 G  provide views of different operational states for valve stem based fluid transfer systems in accordance with some examples of this technology; 
         FIGS.  31 A- 31 D  provide views illustrating control of fluid flow rates in accordance with some examples of this technology; 
         FIGS.  32 A- 32 C  provide views of sealing block and manifold connections in accordance with some examples of this technology; 
         FIGS.  33 A- 33 F  provide views of combined valve housing, sealing connector, manifold, and pressure sensors in accordance with some examples of this technology; 
         FIGS.  34 A- 37 B  provide views of engagement of pressure sensors in accordance with some examples of this technology; 
         FIGS.  38 A and  38 B  various views of a valve housing to manifold connection in accordance with some examples of this technology; 
         FIG.  39    illustrates a positional sensor in valve stem based fluid transfer systems in accordance with some examples of this technology; 
         FIGS.  40 A- 40 C  provide views of an example geartrain transmission used in accordance with some examples of this technology; 
         FIGS.  41 A and  41 B  provide views of an example planetary gear transmission used in accordance with some examples of this technology; 
         FIG.  42    illustrates an example solenoid used in solenoid based fluid transfer systems in accordance with some examples of this technology; 
         FIG.  43   -47B provide views of solenoid based fluid transfer systems in accordance with some examples of this technology; 
         FIGS.  48 A- 48 F  provide views explaining example operational states in accordance with some examples of this technology; 
         FIGS.  49 A- 49 D  provide views explaining additional solenoid based fluid transfer systems and available operational states in accordance with some examples of this technology; 
         FIGS.  50 A and  50 B  include information relating to pressure sensing adjustment in accordance with some examples of this technology; and 
         FIGS.  51 A- 51 F  provide schematic views of different operational states for other solenoid based fluid distributors, fluid transfer systems, sole structures, fluid flow control systems, foot support systems, and/or articles of footwear in accordance with some aspects of this technology. 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of various examples of fluid flow control systems, footwear structures, and components according to the present technology, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration various example structures and environments in which aspects of the technology may be practiced. It is to be understood that other structures and environments may be utilized and that structural and functional modifications may be made to the specifically described structures, functions, and methods without departing from the scope of the present technology. 
     I. General Description of Aspects of This Technology and This Invention 
     Aspects of this technology relate to fluid distributors, fluid flow control systems, foot support systems, sole structures, articles of footwear, and/or other foot-receiving devices, e.g., of the types described and/or claimed below and/or of the types illustrated in the appended drawings. Such fluid distributors, fluid flow control systems, foot support systems, sole structures, articles of footwear, and/or other foot-receiving devices may include any one or more structures, parts, features, properties, and/or combination(s) of structures, parts, features, and/or properties of the examples described and/or claimed below and/or of the examples illustrated in the appended drawings. 
     The following description is broken into three main parts. A first part describes aspects and features of footwear and/or foot-receiving device components, foot-receiving devices, and/or articles of footwear that include components to selectively move fluid within and/or through a fluid distributor to control and change foot support pressure of a foot support system that includes at least one fluid filled bladder. The fluid distributor is capable of placing the fluid flow control system, the foot support system, and/or the article of footwear in a plurality of different operational states. Another main part of this description relates to fluid transfer systems within the fluid distributor that include a movable valve stem to place the fluid flow control system, the foot support system, and/or the article of footwear in different operational states. Another main part of this description relates to fluid transfer systems within the fluid distributor that include one or more solenoid valves to place the fluid flow control system, the foot support system, and/or the article of footwear in different operational states. Various other aspects and features of this technology are described within those main parts. 
     A. Footwear Component and Articles of Footwear Features 
     Some aspects of this technology and this invention relate to foot support systems as well as to sole structures and/or articles of footwear (and/or other foot-receiving devices) that include such foot support systems. Foot support systems in accordance with at least some examples of this technology include: (a) at least one foot support bladder; (b) a first sole member (e.g., a midsole component, a polymeric foam component, an outsole component, etc.) engaged with the foot support bladder, wherein the first sole member includes a plantar support surface at least at a heel support area of the foot support system and a sidewall forming an exterior surface of the first sole member; (c) at least one fluid container (e.g., a fluid-filled bladder, a tank, a reservoir, etc.), optionally engaged with a portion of a footwear upper and/or with a footwear sole structure; and (d) a fluid distributor engaged with the exterior surface of the upper and/or the first sole member. This fluid distributor includes one or more of: (i) an inlet for receiving fluid from a fluid supply, (ii) a first fluid pathway for transferring fluid from the fluid distributor interior to the external environment, (iii) a second fluid pathway in fluid communication with the foot support bladder, and (iv) a third fluid pathway in fluid communication with the fluid container. The fluid distributor may take on the form of or include a manifold, a valve housing, a connector, and/or combinations of two or more of these components. The fluid supply may be one or more of: a pump (e.g., one or more foot activated pumps, one or more battery powered pumps, etc.), a compressor, and/or a fluid supply line in fluid communication with the external environment. 
     Additional aspects and features of foot support systems, sole structures containing them, and/or articles of footwear (or other foot-receiving devices) containing them are described in more detail below. 
     B. Valve Stem Features 
     Some aspects of this technology and this invention relate to fluid transfer systems and/or fluid flow control systems for foot support systems and/or articles of footwear (and/or other foot-receiving devices) that include a movable valve stem for selectively opening and closing fluid pathways and distributing fluid. Such fluid transfer systems and/or fluid flow control systems, as well as foot support systems and/or articles of footwear (and/or other foot-receiving devices) in accordance with at least some examples of this technology include: (a) a valve housing; (b) a valve stem movably mounted in the valve housing, wherein the valve stem includes a first end, a second end, and a perimeter wall extending between the first end and the second end, wherein the first end, the second end, and the perimeter wall define an internal chamber of the valve stem, and wherein the perimeter wall of the valve stem includes a plurality of through holes extending from the internal chamber to an exterior surface of the perimeter wall; (c) a fluid inlet port in fluid communication with the internal chamber; and (d) a manifold in fluid communication with the valve housing. The manifold may include a first fluid flow path that extends through the manifold to a first manifold port, a second fluid flow path that extends through the manifold to a second manifold port, and a third fluid flow path that extends through the manifold to a third manifold port. Movement of the valve stem (e.g., by rotation, sliding, etc.) to a plurality of positions selectively places the fluid transfer system and/or fluid flow control system in a plurality of operational states by placing one or more of the plurality of through holes (formed in the perimeter wall) in fluid communication with the first fluid flow path, the second fluid flow path, or the third fluid flow path. Additional valve stem openings, manifold ports, fluid lines, and/or operational states may be provided, if desired, to accommodate additional foot support bladders and/or fluid containers. 
     Additional aspects and features of valve stem based fluid transfer systems, fluid flow control systems, foot support systems, sole structures containing them, and/or articles of footwear (or other foot-receiving devices) containing them are described in more detail below. 
     C. Solenoid Features 
     Some aspects of this technology and this invention relate to fluid transfer systems and/or fluid flow control systems for foot support systems and/or articles of footwear (and/or other foot-receiving devices) that include one or more solenoids for selectively opening and closing fluid pathways and distributing fluid. Such fluid transfer systems and/or fluid flow control systems, as well as foot support systems and/or articles of footwear (and/or other foot-receiving devices) in accordance with at least some examples of this technology include: (a) a first solenoid including a first port and a second port and switchable between an open configuration and a closed configuration; (b) a second solenoid including a first port and a second port and switchable between an open configuration and a closed configuration; (c) a third solenoid including a first port and a second port and switchable between an open configuration and a closed configuration; (d) a fluid line in fluid communication with the first port of each of the first solenoid, the second solenoid, and the third solenoid; and (e) a manifold having: (i) a first manifold port in fluid communication with the second port of the first solenoid, (ii) a second manifold port in fluid communication with the second port of the second solenoid, and (iii) a third manifold port in fluid communication with the second port of the third solenoid. The first solenoid, the second solenoid, and the third solenoid are independently switchable between their open configuration and their closed configuration to selectively place the fluid transfer system or fluid flow control system in a plurality of operational states. Additional solenoids, manifold ports, fluid lines, and/or operational states may be provided, if desired, to accommodate additional foot support bladders and/or fluid containers. 
     Other example fluid transfer systems and/or fluid flow control systems, as well as foot support systems and/or articles of footwear (and/or other foot-receiving devices) in accordance with at least some examples of this technology and this invention include: (a) a first solenoid including a first port, a second port, and a third port; (b) a second solenoid including a first port and a second port; and (c) a fluid line in fluid communication with the first port of each of the first solenoid and the second solenoid. A manifold may be included in fluid communication with the solenoids. This manifold may include: (a) a first manifold port in fluid communication with the second port of the first solenoid, (b) a second manifold port in fluid communication with the third port of the first solenoid, and (c) a third manifold port in fluid communication with the second port of the second solenoid. The first solenoid may be independently switchable to: (a) a first configuration in which fluid flows through the first solenoid between the first port and the second port and (b) a second configuration in which fluid flows through the first solenoid between the first port and the third port. The second solenoid may be independently switchable between an open configuration and a closed configuration. Simultaneous selective placement of: (a) the first solenoid in one of the first configuration or the second configuration and (b) the second solenoid in one of the open configuration or the closed configuration selectively places the fluid flow control system in a plurality of operational states. Additional solenoids, manifold ports, fluid lines, and/or operational states may be provided, if desired, to accommodate additional foot support bladders and/or fluid containers. 
     Still additional foot support systems, sole structures, and articles of footwear in accordance with aspects of this technology may include: (a) a first foot support bladder; (b) a second foot support bladder; (c) a fluid container; (d) a fluid supply; (e) a first solenoid including a first port in fluid communication with the fluid supply, a second port in fluid communication with the fluid container, and a third port for releasing fluid from the foot support system; (f) a valve in fluid communication with the first port of the first solenoid; and (g) a second solenoid including a first port in fluid communication with the valve, a second port in fluid communication with the first foot support bladder, and a third port in fluid communication with the second foot support bladder. In such systems, sole structures, and articles of footwear: (A) the first solenoid may be independently switchable to: (i) a first configuration in which fluid flows through the first solenoid between the first port and the second port and (ii) a second configuration in which fluid flows through the first solenoid between the first port and the third port, (B) the valve is independently switchable to: (i) an open configuration in which fluid flows through the valve and (ii) a closed configuration in which fluid does not flow through the valve, and (C) the second solenoid is independently switchable to: (i) a first configuration in which fluid flows through the second solenoid between the first port and the second port and (ii) a second configuration in which fluid flows through the second solenoid between the first port and the third port. Simultaneous selective placement of: (1) the first solenoid in one of the first configuration or the second configuration, (2) the valve in one of the open configuration or the closed configuration, and (3) the second solenoid in one of the first configuration or the second configuration selectively places the foot support system in a plurality of operational states. Additional solenoids, fluid lines, and/or operational states may be provided, if desired, to accommodate additional foot support bladders and/or fluid containers. Additional aspects of this technology relate to fluid distribution systems usable with foot support systems, sole structures, and articles of footwear of the types described above to move the fluid as needed to make desired operational states available. 
     Additional aspects and features of solenoid based fluid transfer systems, fluid flow control systems, foot support systems, sole structures containing them, and/or articles of footwear (or other foot-receiving devices) containing them are described in more detail below. 
     D. Operational State Features 
     Some aspects of this technology and this invention relate to fluid transfer systems, fluid flow control systems, foot support systems, and/or articles of footwear (or other foot-receiving devices) that may be selectively placed in a plurality of operational states in which movement and distribution of fluid is controlled. In at least some examples of this technology, the plurality of operational states may include two or more of (in any combination): (a) a first operational state in which fluid moves from a fluid source (e.g., a pump, a compressor, etc.) to the ambient or external environment (e.g., this may be a “steady state” or “standby” configuration in which no foot support pressure changes occur), (b) a second operational state in which fluid moves from a fluid source to a foot support bladder (to increase pressure in the foot support bladder), (c) a third operational state in which fluid moves from a foot support bladder to the ambient or external environment (to decrease pressure in the foot support bladder), (d) a fourth operational state in which fluid moves from a fluid container to the ambient or external environment (to decrease pressure in the fluid container), (e) a fifth operational state in which fluid moves from the fluid container to the foot support bladder (to increase pressure in the foot support bladder), and/or (f) a sixth operational state in which fluid moves from the fluid source to the fluid container (to increase pressure in the fluid container). Some examples of this technology may include all six of these operational states identified above. Other examples of this technology may include less than all six of these operational states, e.g., the first, third, fourth, and six operational states. For valve stem examples of this technology, fluid may be distributed into two or more of these different operational states by selectively moving (e.g., rotating, sliding, etc.) the valve stem to various positions (e.g., rotational positions, longitudinal positions, etc.) so that through holes in the valve stem selectively align with fluid paths and ports to move the fluid in the desired manners described above. For solenoid examples of this technology, fluid may be distributed into these two or more different operational states by selectively placing the various solenoids in their available configurations so that the fluid moves to fluid paths and ports in the desired manners described above. 
     Additional aspects and features of placing fluid transfer systems, fluid flow control systems, foot support systems, sole structures containing them, and/or articles of footwear (or other foot-receiving devices) containing them into various operational states are described in more detail below. 
     E. Additional or Alternative Features 
     Additional or alternative features and aspects of this technology and this invention relate to additional structures, components, and operation of the fluid transfer systems, fluid flow control systems, foot support systems, sole structures, and/or articles of footwear described herein and illustrated in the appended figures. Such additional or alternative features and aspects of this technology and this invention relate to one or more of: (a) user input buttons included with the shoe, e.g., to enter pressure change information and/or provide status information relating to the system(s); (b) external air inlet and/or filtering features for accepting air into the system(s); (c) connections between the ports of various components, such as connector to manifold connections, fluid line to connector and/or manifold connections, etc.; (d) fluid distributor to footwear connection features; (e) valve stem position sensor features; (f) transmission features for transmitting power from a motor to the valve stem; (g) pressure control algorithm features; (h) shoe-to-shoe and/or other system electronic communication features; (i) system sealing features, such as one or more of manifold-to-valve housing, manifold-to-solenoid, and/or manifold-to-connector sealing features; and/or (j) features relating to pressure sensor mounting and engagement with the manifold and/or sealing connector. 
     Some additional or alternative aspects of this technology relate to button assemblies, such as buttons for receiving user input, e.g., changing pressure settings in one or more fluid containing components in the system. One such aspect relates to button assemblies that include: (a) a first button actuator; and (b) an elastomer overmold material covering an actuator surface of the first button actuator. This elastomer overmold material may include: (a) a first base portion having a first thickness and (b) a first groove portion (e.g., U-shaped) adjacent the first button actuator, wherein the first groove portion has a second thickness, wherein the second thickness is less than the first thickness, and wherein the first base portion and the first groove portion are formed as a continuous layer of the elastomer overmold material. The same elastomer overmold material may cover an actuator surface of a second button actuator, wherein the elastomer overmold material further includes: (a) a second base portion (e.g., U-shaped) having a third thickness and (b) a second groove portion adjacent the second button actuator, wherein the second groove portion has a fourth thickness, wherein the fourth thickness is less than the third thickness, and wherein the second base portion and the second groove portion are formed as part of the continuous layer of the elastomer overmold material. In such examples of this technology, the first thickness may be the same as or different from the third thickness and/or the second thickness may be the same or different from the fourth thickness. Still some additional or alternative button assemblies according to aspects of this technology may include: (a) a capacitive touch activator for unlocking the button assembly; (b) a first physical switch button activator for receiving user input; and, if desired, a second (or more) physical switch button activators for receiving user input. 
     One more specific additional or alternative aspect of this technology relates to filtered fluid flow connectors for articles of footwear that include: (a) a housing; (b) an incoming fluid inlet extending through the housing; (c) an incoming fluid outlet extending through the housing; (d) a filter for filtering incoming fluid before the incoming fluid reaches the incoming fluid outlet; (e) a pumped fluid inlet extending through the housing, a pumped fluid outlet extending through the housing, and a pumped fluid line within the housing and connecting the pumped fluid inlet and the pumped fluid outlet; and (f) a first foot support bladder port extending through the housing, a second foot support bladder port extending through the housing, and a foot support fluid line within the housing and connecting the first foot support bladder port and the second foot support bladder port. Such filtered fluid flow connectors further may include: (a) a first fluid container port extending through the housing, a second fluid container port extending through the housing, and a fluid container fluid line within the housing and connecting the first fluid container port and the second fluid container port, and/or (b) a fluid release port extending through the housing. In some examples, the filter may have a surface with an area of at least 50 mm 2  positioned to form or cover at least a portion of an exterior surface of the housing and to cover the incoming fluid inlet. 
     Still additional or alternative aspects of this technology relate to fluid flow connector systems for articles of footwear that include: (a) a manifold having a first port; (b) a connector having: (i) a first port in fluid communication with the first port of the manifold, (ii) a second port, and (iii) a first internal connector fluid line connecting the first port of the connector and the second port of the connector; and (c) a first fluid line in fluid communication with the second port of the connector and in fluid communication with the first port of the manifold through the first internal connector fluid line. Additional manifold ports may be connected to additional fluid lines through additional ports and fluid paths defined in the connector, if desired. As alternatives, some aspects of this technology may include fluid flow connector systems for articles of footwear that include: (a) a manifold having a first port, a second port, and a first internal manifold fluid line connecting the first port and the second port; (b) a fluid transfer system in fluid communication with the first port of the manifold; and (c) a first external fluid line in fluid communication with the second port of the manifold, e.g., without an intermediate connector between the manifold and fluid paths. At least some of the internal fluid paths extending through the connector (when the connector is present) or through the manifold (e.g., when no separate connector is present) may define: (a) a first axial direction, (b) a second axial direction, and (c) a connecting portion joining the first axial direction and the second axial direction. In such structures, the first axial direction and the second axial direction may extend away from one another from the connecting portion of the internal fluid path(s) at an angle of 70 degrees or less (and in some examples, at an angle of 60 degrees or less, 50 degrees or less, 40 degrees or less, 30 degrees or less, 20 degrees or less, or even parallel). In this manner, fluid entering and leaving the connector (when present) or the manifold (if no separate connector is present) may do so within angles of 70 degrees or less from one another. 
     Additional or alternative aspects of this technology relate to methods of making sole structures for articles of footwear that include fluid flow control systems of the types described herein engaged with them. Some such methods may include: (a) engaging a first fluid line that extends from a first sole component with a first port of a connector, wherein the first port of the connector is in fluid communication with a second port of the connector by a first internal connector fluid line that extends through the connector; (b) engaging the second port of the connector with a first manifold port of a fluid distributor; and (c) engaging the fluid distributor and the connector as a single connected component with at least one of the first sole component or a different sole component. Such methods may include engaging additional fluid lines from sole components with the connector as part of the single connected component prior to engaging the single connected component with the first sole component or a different sole component. Still additional or alternative aspects of this technology include methods comprising: (a) engaging a first fluid line that extends from a first sole component with a first port of a manifold of a fluid distributor, wherein the first port of the manifold is in fluid communication with a second port of the manifold by a first internal manifold fluid line that extends through the manifold; and (b) engaging at least one of the first sole component or a different sole component with the fluid distributor having the first fluid line engaged with the first port of the manifold. Such methods may include engaging additional fluid lines from the same or other sole components with corresponding manifold ports prior to engaging the fluid distributor with the first sole component or the different sole component. Still additional aspects of this technology relate to the sole structures resulting from the methods described above, irrespective of any specific method used to the make the sole structures (e.g., sole structures having connections as described above irrespective of the method steps and/or order of method steps used to make the sole structures). 
     Still additional or alternative aspects of this technology relate to fluid transfer systems for articles of footwear that include: (a) a valve housing defining an interior chamber; (b) a valve stem extending at least partially through the interior chamber, the valve stem having: (i) a first end operatively coupled with a motor to move the valve stem with respect to the valve housing, (ii) a second end opposite the first end, and (iii) a perimeter wall extending from the first end to the second end; and (c) a position sensor for determining a position of the valve stem with respect to the valve housing or other component of the fluid transfer system, the position sensor including: (i) an encoder magnet movable with (e.g., engaged with) the valve stem (e.g., at the first end, second end, or between), and (ii) an encoder sensor (e.g., engaged with the valve housing) sensing changes in a magnetic field generated by the encoder magnet due to the position of the valve stem. In some examples, the encoder sensor may be located closer to the second end than to the first end of the valve stem. 
     Other additional or alternative aspects of this technology relate to transmissions for fluid transfer systems incorporated into articles of footwear. Such transmissions may include: (a) a motor pinion; (b) a first intermediate gear cluster including: (i) a first axial pin, (ii) a first gear having a first central axis coaxial with the first axial pin and engaging the motor pinion, the first gear having a first diameter, and (iii) a second gear having a second central axis coaxial with the first axial pin, the second gear having a second diameter different from the first diameter; (c) a second intermediate gear cluster including: (i) a second axial pin, (ii) a third gear having a third central axis coaxial with the second axial pin and engaging the second gear, the third gear having a third diameter, and (iii) a fourth gear having a fourth central axis coaxial with the second axial pin, the fourth gear having a fourth diameter different from the third diameter; (d) a third axial pin; and (e) a fifth gear having a third central axis coaxial with the third axial pin and engaging the fourth gear, wherein the third central axis of the fifth gear is coaxial with a rotational axis of an output of the transmission. Additional gears may be included, if necessary or desired, for a particular function or operation. Additionally or alternatively, aspects of this technology may relate to drive systems for fluid transfer systems in articles of footwear that include: (a) a motor including a drive shaft; (b) a valve stem; and (c) a three (or more) stage transmission operative coupled between the drive shaft and valve stem to rotate the valve stem in response to rotation of the drive shaft. If desired, the three stage transmission may comprise a transmission of the type described above. 
     Additional or alternative aspects of this technology relate to electronic communications between components of different shoes. Footwear systems in accordance with at least some of these aspects may include: (a) a first shoe having a first footwear component with pressure adjustment capability, a first microprocessor, and a first antenna in electronic communication with the first microprocessor; (b) a second shoe having a second footwear component with pressure adjustment capability, a second microprocessor, and a second antenna in electronic communication with the second microprocessor; and (c) a central communication source for transmitting data to at least one of the first antenna or the second antenna in response to input data directing a pressure change in at least one of the first footwear component or the second footwear component. In some examples, the central communication source is located in the first shoe, and the first shoe transmits data from the first antenna to the second antenna when the input data directs a pressure change in the second footwear component. In other examples: (a) during a first time period, the central communication source is located in the first shoe and the first shoe transmits data from the first antenna to the second antenna when the input data directs a pressure change in the second footwear component, and (b) during a second time period, the central communication source is located in the second shoe and the second shoe transmits data from the second antenna to the first antenna when the input data directs a pressure change in the first footwear component. 
     In other examples, the central communication source may constitute an external computing device not physically incorporated in either of the first shoe or the second shoe (e.g., a smartphone, a personal computer, etc.). In such examples, the external computing device may: (a) transmit data to the first antenna when the input data directs a pressure change in the first footwear component, and/or (b) transmit data to the second antenna when the input data directs a pressure change in the second footwear component, and/or (c) transmit data to the first antenna when the input data directs a pressure change in the first footwear component or the second footwear component, and then the first antenna transmits data to the second antenna when the input data directs a pressure change in the second footwear component. In still other examples of this aspect of the technology, communication of the input data directing the pressure change may be switchable between at least three communication configurations as follows: (a) a first communication configuration when an external computing device is in electronic communication with at least one of the first shoe or the second shoe, wherein the external computing device acts as the central communication source and each of the first shoe and the second shoe act as peripheral communication devices receiving pressure change input from the external computing device, (b) a second communication configuration when no external computing device is in electronic communication with the first shoe or the second shoe, wherein the first shoe acts as the central communication source and the second shoe acts as a peripheral communication device receiving pressure change input from the first shoe, and (c) a third communication configuration when no external computing device is in electronic communication with the first shoe or the second shoe, wherein the second shoe acts as the central communication source and the first shoe acts as a peripheral communication device receiving pressure change input from the second shoe. 
     Such footwear communication systems further may be in electronic communication with at least one additional electronically adjustable component. Such additional electronically adjustable component(s) may include one or more of: an apparel based adjustable component on an article of apparel separate from the first shoe and the second shoe, a motorized apparel component, a motorized lacing system for tightening or loosening lacing systems on at least one of the first shoe or the second shoe, a motorized shoe securing system for at least one of the first shoe or the second shoe, a motorized fluid containing sports bra, and a motorized fluid containing compression sleeve. 
     Still additional or alternative aspects of this technology relate to sealed connections between various parts. One example sealed connection extends between a rotatable valve stem having a peripheral wall including at least a first fluid port extending through it and a manifold including at least a first manifold port. A sealing connector (e.g., made of rubber or elastomer) may join these parts. The sealing connector may include: (a) a first connector port in direct contact with the peripheral wall (to seal against the peripheral wall), (b) a second connector port connected to the first manifold port, and (c) a first connector fluid path extending between the first connector port and the second connector port. Rotation of the rotatable valve stem to a first position at least partially aligns the first fluid port of the rotatable valve stem with the first connector port to place the first fluid port of the rotatable valve stem in fluid communication with the first manifold port through the first connector fluid path in a sealed condition. Such sealed connections and sealing connectors may include one or more additional ports in the valve stem, a corresponding one or more additional ports in the manifold, and a corresponding additional one or more sets of connector ports and connector fluid paths in the connector joining the corresponding ports of the valve stem and manifold. Different rotary positions of the valve stem may selectively align the ports to open one or more sets of fluid pathways at a time. Any one or more of the connector ports in direct contact with the peripheral wall (including all such connector ports) may include a curved outer surface shaped to correspond to a curvature of an outer surface of the peripheral wall and/or to seal that directly contacting port with the peripheral wall. This curved outer surface rides along (moves with respect to) the peripheral wall (and maintains sealed contact during rotation) when the valve stem is rotated. A lubricant may help support this relative sliding action and help maintain a sealed connection. Other sealed connections also may be provided in the overall systems described herein. 
     Additional or alternative aspects of this technology relate to inclusion of pressure sensors in fluid flow control system for articles of footwear. Such fluid flow control systems may include: (a) a fluid distributor; (b) a manifold including: (i) a manifold body, (ii) a first manifold fluid path defined through the manifold body and extending from a first manifold port that is in fluid communication with the fluid distributor to a second manifold port that is in fluid communication with a first footwear component, (iii) a first pressure sensor mount (e.g., one or more of a recess or a raised tube) defined in the manifold body or extending from the manifold body, and (iv) a first open channel extending between the first pressure sensor mount and the first manifold fluid path; and (c) a first pressure sensor mounted at the first pressure sensor mount in a fluid tight manner. Additional manifold ports, manifold fluid paths, pressure sensor mounts, and open channels may be provided, e.g., for additional pressure sensors for measuring pressure in other fluid lines. Additionally or alternatively, fluid flow control systems for articles of footwear may include: (a) a fluid distributor; (b) a manifold including a first manifold port; (c) a sealing connector including: (i) a connector body, (ii) a first connector fluid path defined through the connector body and extending from a first connector port that is in fluid communication with the fluid distributor to a second connector port that is in fluid communication with the first manifold port, (iii) a first pressure sensor mount (e.g., one or more of a recess or a raised tube) defined in the connector body or extending from the connector body, and (iv) a first open channel extending between the first pressure sensor mount and the first connector fluid path; and (d) a first pressure sensor mounted at the first pressure sensor mount in a fluid tight manner. In such systems, additional manifold ports, connector ports, connector fluid paths, pressure sensor mounts, and open channels may be provided, e.g., for additional pressure sensors for measuring pressure in other fluid lines. 
     Additional or alternative aspects of this technology relate to systems and methods for changing fluid pressure in a component of an article of footwear. Such systems and methods may include hardware and/or software for performing a method comprising: (a) receiving input data indicating a target pressure for fluid pressure in a first footwear component, wherein the first footwear component is a foot support bladder or a fluid container; (b) moving fluid through a continuous fluid line that extends between a first port of a manifold or a sealing connector and a second port of the manifold or sealing connector, wherein the first port is in fluid communication with the first footwear component, and wherein the second port is in fluid communication with a second footwear component or an external environment; (c) measuring fluid pressure in the continuous fluid line as fluid moves through the continuous fluid line using a first pressure sensor; (d) determining an adjusted fluid pressure based on the fluid pressure measured by the first pressure sensor during the measuring step; and (e) stopping fluid flow through the continuous fluid line when the adjusted fluid pressure determined in the determining step is within a predetermined range of the target pressure. The adjusted fluid pressure estimates fluid pressure in the first footwear component. In some examples of this technology, the adjusted fluid pressure corrects for flow rate dependent offset between the fluid pressure measured by the first pressure sensor during the measuring step and actual fluid pressure in the first footwear component. Such flow rate dependent offset may be caused, for example, by fluid flowing through fluid lines having a small internal cross sectional area or diameter (e.g., less than 50 mm 2 , and in some examples, less than 40 mm 2 , less than 30 mm 2 , less than 20 mm 2 , or even less than 16 mm 2 ). 
     Given the general description of features, examples, aspects, structures, processes, and arrangements according to examples of this technology and this invention provided above, a more detailed description of specific example fluid transfer systems, fluid flow control systems, foot support systems, sole structures, articles of footwear, and methods in accordance with this technology follows. 
     II. Detailed Description of Example Articles of Footwear, Foot Support Systems, and Other Components and/or Features According to this Technology 
     Referring to the figures and following discussion, various examples of foot support systems, fluid flow control systems, sole structures, and articles of footwear in accordance with aspects of this technology are described. Aspects of this technology may be used, for example, in conjunction with foot support systems, articles of footwear (or other foot-receiving devices), and/or methods described in the various U.S. patent applications noted above. 
     A. Footwear Structures 
     As noted above, some aspects of this technology relate to foot support systems, sole structures, and/or articles of footwear (and/or other foot-receiving devices) that may be placed in various different operational states.  FIG.  1    generally shows an article of footwear  100  (side view) in accordance with some examples of this technology including an upper  102  and a sole structure  104  engaged with the upper  102 . Both the upper  102  and the sole structure  104  may be made from one or more component parts, including conventional component parts as are known and used in the footwear arts. The various parts of the article of footwear  100 , including the upper  102  and sole structure  104  and/or the individual component parts thereof, may be engaged together in any desired manner, including in conventional manners as are known and used in the footwear art. The upper  102  of this example includes a foot-receiving opening  106  that opens into an interior chamber (defined by the upper  102  and/or sole structure  104 ) for a user’s foot. A securing system  108  (e.g., laces shown, although other types may be used) allows the article of footwear  100  to be releasably secured to the user’s foot. 
     As further shown in  FIG.  1   , this article of footwear  100  includes a foot support system having a foot support bladder  200  for supporting at least a portion of a plantar surface of a user’s foot (the forefoot area in this specifically illustrated example). The foot support system further includes an “on-board” fluid container  400 . The fluid container  400  contains fluid (e.g., under pressure), and in this illustrated example is comprised of a fluid filled bladder. The fluid container  400  may be located above an outsole component of the footwear  100 , within a midsole component (e.g., in a cavity of a foam part), and/or engaged with the upper  102 . A fluid distributor (to be described in more detail below) selectively places the foot support system and/or article of footwear  100  in two or more operational states, e.g., to move fluid from the fluid container  400  to the foot support bladder  200 ; from a fluid supply into the fluid container  400  and/or into the foot support bladder  200 ; and from a fluid supply, the fluid container  400 , and/or the foot support bladder  200  to the ambient or external environment. The fluid distributor may include one or more of: a component with a movable valve stem; a component with one or more solenoids; a manifold connected with the valve stem and/or solenoid(s) (e.g., with their housings); a connector connecting components of the fluid distributor with a fluid supply and/or fluid transfer lines; and/or one or more fluid transfer lines. 
       FIGS.  2 A and  2 B  show top and exploded views, respectively, of portions of an article of footwear  100  that include various features in accordance with aspects of this technology. As shown, this example foot support system includes the fluid-filled foot support bladder  200  for supporting at least a forefoot portion of a user’s foot. A portion of the fluid container  400  of this example (also a fluid-filled bladder) is located beneath the foot support bladder  200 , and it extends rearward beyond the rear edge of the foot support bladder  200  (note also  FIG.  1   ). An upper sole component  104 U (e.g., an upper midsole component optionally formed of a polymeric foam material) overlies and/or engages the foot support bladder  200 . A lower sole component  104 L (e.g., a lower midsole component optionally formed of a polymeric foam material) underlies and/or engages the foot support bladder  200 . In this illustrated example, both the upper sole component  104 U and the lower sole component  104 L extend rearward and include plantar support surfaces  104 US and  104 LS, respectively, at least at a heel support area of the sole structure  104 . Also, both the upper sole component  104 U and the lower sole component  104 L in this illustrated example include openings  104 UO and  104 LO, respectively, extending completely through them at the forefoot support area. These openings  104 UO,  104 LO correspond to forefoot portions of the foot support bladder  200  and the fluid container  400  in this illustrated example so that, if desired, at least portions of the top surface  400 S of the fluid container  400  and the bottom surface  200 S of the foot support bladder  200  directly face and/or contact one another at least in their forefoot support areas in the final assembled sole structure  104 . 
     One or more cage components  300  may be provided, e.g., formed of polymeric material (e.g., a thermoplastic polyurethane, etc.), to secure the foot support bladder  200 . A multi-part cage component  300  is shown in  FIG.  2 B  including a lateral cage component  300 L, a medial cage component  300 M, and a middle or rear cage component  300 R. The lateral cage component  300 L and the medial cage component  300 M engage corresponding sidewalls of the lower sole component  104 L and/or corresponding sidewalls of the foot support bladder  200 , and the middle or rear cage component  300 R engages the rear edge of foot support bladder  200 . If desired (and as shown in  FIG.  2 B ), at least one of the lateral cage component  300 L and the medial cage component  300 M may include openings defined through them so that the sidewall(s) of the foot support bladder  200  may be exposed and visible at the exterior of the sole structure  104  in the final assembled sole structure  104 . See  FIG.  1   . This example sole structure  104  further includes an optional shank  120  in the midfoot area. This example shank  120  includes a generally U-shaped opening having arms to support bottom side edges of the foot support bladder  200  and/or a rear base area to support the bottom rear of the foot support bladder  200 . 
     The upper sole component  104 U of this example includes a sidewall  104 S (e.g., extending upward from the plantar support surface  104 US) forming a portion of its exterior surface. The exterior lateral side of sidewall  104 S has a recess  104 R defined in it. This recess  104 R receives a fluid distributor  500 . In this illustrated example, the lateral cage component  300 L extends rearward and forms a portion of a base that is received in the recess  104 R, and this base is engaged with and/or forms at least some portion of the fluid distributor  500  (e.g., part of its housing  502 ). Alternatively, if desired, the fluid distributor  500  may be an independent part from lateral cage component  300 L and/or directly engaged with the exterior surface of the upper sole component  104 U (or other footwear component part and/or upper  102  part). 
     Several features and components of the fluid distributor  500  are described in detail below. In some examples of this technology, the fluid distributor  500  includes or defines: (a) an inlet for receiving fluid from a fluid supply (e.g., from the external environment, from another internal fluid line, from a pump or compressor, etc.), (b) a first fluid pathway for transferring fluid to the external environment (e.g., to exhaust excess gas introduced by the fluid supply, to reduce pressure in the foot support bladder  200 , to reduce pressure in the fluid container  400 , etc.), (c) a second fluid pathway in fluid communication with the foot support bladder  200  (e.g., to move fluid into and/or out of the foot support bladder  200  and/or to change fluid pressure in the foot support bladder  200 ), and/or (d) a third fluid pathway in fluid communication with the fluid container  400  (e.g., to move fluid into and/or out of the fluid container  400  and/or to change fluid pressure in the fluid container  400 ). 
       FIG.  2 B  further illustrates a fluid transfer line  200 F or tube extending to foot support bladder  200  and a tube recess  200 R formed within the sidewall recess  104 R. The tube recess  200 R provides room to allow fluid flow lines to meet and join up with the fluid distributor  500  as will be described in more detail below. Also, while not shown in  FIG.  2 B , sole structures  104  of this type may include a pump (e.g., a foot activated pump, a battery operated pump, a compressor, etc.) that acts as at least a portion of a fluid supply and/or an outsole component  1040  (see  FIG.  3 B ) (e.g., to cover and protect the fluid container  400 ). 
     As mentioned above and shown in the examples of  FIGS.  3 A- 3 D , at least some examples of this technology will include a fluid supply in the form of one or more pumps, including one or more foot-activated pumps. When one pump is present, it may move fluid received from the external environment via a fluid pathway extending from the external environment to the pump to the fluid distributor  500  for distribution to a final desired destination (e.g., the foot support bladder  200 , the fluid container  400 , or back to the external environment). Alternatively,  FIG.  3 A  shows a two stage pumping system including a heel activated bulb pump  600 H (which also is referred to as a “first pump” herein) that is connected via fluid line  602  to forefoot activated bulb pump  600 F (which is also referred to as a “second pump” herein) in “series.” Thus, in at least some examples of this technology: (a) an inlet  600 HI of the heel activated pump  600 H is in fluid communication with the external environment (e.g., by a fluid path extending from the external environment to the inlet  600 HI through the fluid distributor  500 , such as fluid line  604 ); (b) an outlet  600 HO of the heel activated pump  600 H is in fluid communication with an inlet  600 FI of the forefoot activated pump  600 F via fluid line  602 , and (c) an outlet  600 FO of the forefoot activated pump  600 F is in fluid communication with an inlet of the fluid distributor  500 , such as fluid line  606 . The “upstream” pump ( 600 H in this description, but could be  600 F in some examples) may be somewhat larger than the “downstream” pump ( 600 F in this description, but could be  600 H in some examples), to improve fluid flow and pumping efficiency. A two-stage pump may have features and/or structures like those shown in corresponding structures disclosed in U.S. Pat. Appln. No. 16/698,138 filed Nov. 27, 2019. 
     Additionally or alternatively, if desired, when more than one pump is present, more than one pump may move fluid to an inlet of the fluid distributor  500  (e.g., two or more pumps may have their outlets connected directly to an inlet of fluid distributor  500 ). Once pumped into the fluid distributor  500 , the fluid distributor  500  selectively moves the fluid to its ultimate destination, e.g., the foot support bladder  200 , the fluid container  400 , or back to the external environment, depending on its operational state. An exhaust valve or check valve may be provided with any pumps  600 H,  600 F present to prevent an overpressure situation (e.g., should the fluid lines and/or components downstream from the pumps  600 H,  600 F become blocked or non-functional for any reason). The pump(s)  600 F,  660 H may be made, e.g., from RF welded TPU films bonded together to make a bulb type pumping chamber in known manners. 
       FIG.  3 A  illustrates generally spheroid or ellipsoid shaped bulb pumps  600 H,  600 F.  FIGS.  3 B- 3 D , on the other hand, shows generally T-shaped bulb pumps  600 H,  600 F, with the forefoot bulb pump  600 F oriented more under the metatarsal head support areas of the sole structure  104  (as opposed to more in the toe support areas in  FIG.  3 A ).  FIG.  3 B  shows general potential locations for the pumps  600 H,  600 F in a sole structure  104 .  FIG.  3 C  shows an overall arrangement of the pumps  600 H,  600 F and their connecting lines, and  FIG.  3 D  shows a closer view of a T-shaped bulb pump (e.g.,  600 H in this example), which may be in fluid communication with a forefoot pump  600 F, a fluid distributor  500 , or another footwear component. 
     The T-shaped bulb pumps  600 H,  600 F may be made somewhat wider and less round than spheroid or ellipsoid to distribute the pump chamber volume over a larger (e.g., wider) area of the user’s foot (and thus make the pump(s)  600 H,  600 F feel less perceptible underfoot). These T-shaped bulb pumps  600 H,  600 F also may be connected in “series” (e.g., with the outlet  600 HO of pump  600 H feeding into the inlet  600 FI of pump  600 F and the outlet  600 FO of pump  600 F acting as a fluid source for the fluid distributor  500 , foot support systems, sole structures  104 , and/or articles of footwear  100 , e.g., via fluid line  606 ). The bulb pumps  600 H,  600 F may be sandwiched between sole components, such as between the lower sole component  104 L and one or more outsole components  1040 . As an alternative, if desired, a forefoot outsole component  104 OF may be provided to engage forefoot pump  600 F and a separate heel outsole component ( 104 OH) may be provided to engage the heel pump. In use, when a user lands a step or jump, the bulb pump  600 H and/or  600 F will compress between the sole components under the applied force (the user’s weight), thereby forcing fluid out of the bulb pump  600 H and/or  600 F outlet  600 HO,  600 FO and moving fluid from the pumps  600 H,  600 F to the fluid distributor  500 . One-way valves may be provided to prevent backward fluid flow through the pump(s)  600 F,  600 H. The bulb pump(s)  600 H,  600 F may be attached to and/or located between flat or smoothly curved foam, bladder, outsole, or other sole component surfaces (e.g., to increase pumping volume per step). If necessary, however, the bulb pump(s)  600 H,  600 F may be at least partially received within a recess in at least one of the components to which it is attached (e.g., within a recess in one or more of a foam, bladder, outsole, or other sole component surface). 
       FIGS.  4 A- 5 F  schematically illustrate fluid distributor  500  and foot support systems in accordance with at least some examples of this technology and their operation in various potential operational states. As shown and described above, these systems include a foot support bladder  200 , a fluid container or reservoir  400  (which also may include a fluid-filled bladder), and at least one pump (e.g., a heel based pump  600 H and a forefoot based pump  600 F connected in series by fluid line  602  shown). These parts are operatively connected to a fluid flow control system or fluid distributor  500 , which may include some or all of the component parts shown in broken lines in  FIG.  4 A . The fluid distributor  500  of this example serves as a central hub to which fluid comes from various starting locations (e.g., the external or ambient environment  150  or other fluid source; the pump(s)  600 H,  600 F; the foot support bladder  200 ; or the fluid container  400 ) and from which the fluid leaves to go to various destinations (e.g., the external or ambient environment  150 ; the foot support bladder  200 ; or the fluid container  400 ). The fluid distributor  500  of this example includes a connector  700 , a manifold  800 , and a fluid transfer system  900 . 
     The fluid transfer system  900  shown in  FIG.  4 A  can take on a variety of forms and/or structures.  FIG.  4 B  illustrates various example arrangements of different types of fluid transfer systems  900  in a fluid distributor  500 . The fluid transfer system toward the top right of  FIG.  4 B  includes a valve stem based fluid transfer system  900 A. The central fluid transfer systems shown in  FIG.  4 B  are solenoid based fluid transfer systems  900 B,  900 C. The fluid transfer system toward the bottom left of  FIG.  4 B  also is a valve stem based fluid transfer system  900 D, but this fluid transfer system  900 D includes a planetary gear type transmission  922 B as opposed to the geartrain transmission  922  provided in fluid transfer system  900 A. These different fluid transfers systems  900 A,  900 B,  900 C,  900 D (as well as variations thereof) are described in more detail below and may be included in the housings  502  of fluid distributor  500 . 
     Various fluid lines connect fluid distributor  500  with the various fluid starting locations and destinations. These fluid lines are described in more detail in conjunction with the various operational states shown in  FIGS.  5 A- 5 F . The large “X’s” in  FIGS.  5 A- 5 F  show fluid paths of the fluid transfer system  900  that may be closed off in that operational state. When needed, these fluid paths may be closed off in any desired manner, e.g., by a check valve or one-way valve (e.g., in the fluid line  606  from the pump(s)  600 H,  600 F), due to features of the valve stem, due to solenoid valve configurational features, etc. 
       FIG.  5 A  shows an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is discharged back to the external environment  150 . The fluid flow in this operational state is shown by the thick, arrowed, broken lines. This operational state may be used as a “standby” or “steady state” operational state to keep the pumped fluid moving through the fluid distributor  500  even when no pressure changes are needed to the foot support bladder  200  and/or the fluid container  400 . In this operational state, incoming fluid from the external environment  150  (e.g., air) enters the connector  700  via filter  702  and connector inlet  702 I. If necessary or desired, the filter  702  may be removable, replaceable, and/or otherwise cleanable (e.g., to maintain adequate air intake into the system from the external environment  150 ). While any desired intake size may be used, in some aspects of this technology, the filter  702  may have an area of at least 50 mm 2 , an area between 50 mm 2  to 100 mm 2 , an area between 50 mm 2  to 150 mm 2 , and area between 25 mm 2  to 250 mm 2 , or other desired area. Any desired type of filter media, filter construction, and/or filter material may be used, such as a flat sheet of filter material, a flat screen, etc. The filter  702  may provide a relatively large exterior area of the connector  700 , potentially providing at least a majority of the surface area of one exposed outer surface of the connector  702 , e.g., as shown in  FIGS.  5 A- 5 E,  11 A,  12 A, and  13 B . Additionally or alternatively, if desired, a filter may be provided at other locations within the connector  700  and/or within the fluid flow paths (e.g., somewhere before inlet to pump(s)  600 H,  600 F, extending at least partially inside the connector  700  body, extending at least partially inside a dedicated fluid path  702 P, etc.). 
     From connector inlet  702 I, fluid travels through the connector body (e.g., through fluid path  702 P or an open interior space  710  inside connector  700 ) and out through port  702 O. In some examples of this technology, a dedicated fluid path  702 P (e.g., a closed fluid tube) could be omitted (or made non-continuous with open ends inside the connector  700  interior space  710 ) such that fluid may enter into open interior space  710  from the connector inlet  702 I and/or flow out of this open interior space  710  at an opening providing as port  702 O. In such examples, the open interior space  710  may be considered as at least part of fluid path  702 P through the connector  700 . Outlet  702 O connects to a fluid path  604  that takes the fluid to the pump system (pump(s)  600 H,  600 F and fluid line  602  connecting them, in this example). From the pump(s)  600 H,  600 F, fluid travels down a fluid line  606  back to an inlet port  704  of the connector  700 . A one-way valve or a check valve along fluid line  606  may be present to prevent fluid from flowing back toward the pump(s)  600 H,  600 F through connector inlet port  704  and/or fluid line  606 . From connector inlet port  704 , fluid flows through the connector  700  via a connector fluid path  704 P (also called a “fourth connector fluid path” herein), to a connector outlet port  704 O (also called a “fourth fluid path connector” herein), and to an incoming fluid port  800 A of the manifold  800 . Fluid flows from the incoming fluid port  800 A, through a fluid inlet path  802  in the manifold  800 , through a fluid inlet port  800 I and into the fluid transfer system  900 . In this operational state, fluid leaves the fluid transfer system  900 , passes through a first manifold port  804 , through a first manifold fluid flow path  806  defined in the manifold  800 , through another manifold port  800 B, to a first fluid path connector (or port)  706  of the connector  700 , through the first connector fluid path  708 , and optionally to the external environment  150 . Additionally or alternatively, fluid passing through first fluid path connector  706  may empty into the interior space  710  within the connector  700  (and thus become part of the external environment) and/or be available for another pump cycle. 
     Alternatively, in some examples of this technology, in this operational state, rather than continuously moving fluid through the fluid distributor  500  with each step when it is simply going to be discharged back into the external environment  150 , a selectively operable fluid path could be provided from the pump(s)  600 H,  600 F directly to the external environment  150 . As another option, when no fluid pressure changes are needed, the pump(s)  600 H,  600 F could be deactivated. 
       FIG.  5 B  shows an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is transferred to the foot support bladder  200 . Again, the fluid flow in this operational state is shown by the thick, arrowed, broken lines. This operational state may be used to increase pressure in the foot support bladder  200 , e.g., for a firmer feel and/or more intense activities (such as running). In this operational state, incoming fluid from the external environment  150  (e.g., air) moves through the connector  700 , through the manifold  800 , and into the fluid transfer system  900  in the same manner (and through the same components) as described above for  FIG.  5 A . In this operational state, however, fluid leaves the fluid transfer system  900 , passes through a second manifold port  808 , through a second manifold fluid flow path  810  defined in the manifold  800 , through another manifold port  800 C, to a second fluid path connector (or port)  712  of the connector  700 , through the second connector fluid path  714 , through another connector port  720 , into a foot support fluid line  202 , and into the foot support bladder  200 . 
     In some instances, it may be desired to remove fluid from the foot support bladder  200  in order to decrease pressure in the foot support bladder  200  (e.g., to provide a softer feel or for less intense activities, such as walking or casual wear). An example of this operational state is shown in  FIG.  5 C , and the fluid flow is shown by the thick, arrowed, broken lines. In this operational state, fluid leaves the foot support bladder  200 , enters foot support fluid line  202 , passes into the second connector fluid path  714  via connector port  720  and to second fluid path connector  712  of the connector  700 . From the second fluid path connector  712 , fluid passes through manifold port  800 C and into the second manifold fluid flow path  810  defined in the manifold  800 , through the second manifold port  808  and into the fluid transfer system  900 . From here, in this example system and operational state, the fluid is discharged to the external environment  150 . This occurs by the fluid leaving the fluid transfer system  900 , passing through the first manifold port  804 , through the first manifold fluid flow path  806  defined in the manifold  800 , through manifold port  800 B to the first fluid path connector (or port)  706  of the connector  700 , and through the first connector fluid path  708  to the external environment  150  (which may constitute an interior space  710  within the connector  700 ). First connector fluid path connector (or port)  706  may form a port for bringing fluid to be released from the overall system (a “fluid release port”) back to the connector  700  to enable the fluid release. 
     Another potential operational state for fluid distributor  500  and foot support systems in accordance with some examples of this technology is shown in  FIG.  5 D . In this operational state, fluid is transferred from the fluid container  400  to the external environment  150 , e.g., to reduce fluid pressure in the fluid container  400 . The fluid flow of this operational state is shown by the thick, arrowed, broken lines. In this operational state, fluid leaves the fluid container  400 , enters a fluid container fluid line  402 , passes into a third connector fluid path  716  via connector port  722  and to a third fluid path connector (or port)  718  of the connector  700 . From the third fluid path connector  718 , fluid passes through manifold port  800 D and into a third manifold fluid flow path  812  defined in the manifold  800 , through a third manifold port  814  and into the fluid transfer system  900 . From here, in this example system and operational state, the fluid is discharged to the external environment  150 . This occurs by the fluid leaving the fluid transfer system  900 , passing through the first manifold port  804 , through the first manifold fluid flow path  806  defined in the manifold  800 , through manifold port  800 B to the first fluid path connector (or port)  706  of the connector  700 , and through the first connector fluid path  708  to the external environment  150  (which may constitute an interior space  710  within the connector  700 ). 
     In some examples of fluid distributors  500  and foot support systems according to aspects of this technology, it may be desired to use the on-board fluid container  400  to adjust (and in this example, increase) fluid pressure in the foot support bladder  200 . This may allow more predictable or controlled fluid transfer over time as less influence in fluid flow from pressure spikes due to foot contact with the ground may be experienced. An example of this operational state is shown in  FIG.  5 E . In this operational state, fluid leaves the fluid container  400 , enters the fluid container fluid line  402 , passes into the third connector fluid path  716  via connector port  722  and to the third fluid path connector  718  of the connector  700 . From the third fluid path connector port  718 , fluid passes through manifold port  800 D into the third manifold fluid flow path  812  defined in the manifold  800 , through the third manifold port  814  and into the fluid transfer system  900 . From here, in this example system and operational state, the fluid is transferred to the foot support bladder  200 . This occurs by the fluid leaving the fluid transfer system  900 , passing through the second manifold port  808 , through the second manifold fluid flow path  810  defined in the manifold  800 , through manifold port  800 C to the second fluid path connector  712  of the connector  700 , through the second connector fluid path  714  to connector port  720 , into foot support fluid line  202 , and into the foot support bladder  200 . 
       FIG.  5 F  shows an example operational state for adding fluid to the fluid container  400  (e.g., to increase fluid volume and/or pressure in the fluid container  400 ). In this operational state, incoming fluid from the external environment  150  (e.g., air) enters the connector  700  via filter  702  and connector inlet  702 I. From connector inlet  702 I, fluid travels through the connector body to connector outlet port  702 O and to a fluid path  604  that takes the fluid to the pump system (pump(s)  600 H,  600 F). From the pump(s)  600 H,  600 F, fluid travels down a fluid line  606  back to an inlet port  704  of the connector  700 . A one-way valve or a check valve along fluid line  606  may be present to prevent fluid from flowing back toward the pump(s)  600 H,  600 F through connector inlet port  704  and/or fluid line  606 . From connector inlet port  704 , fluid flows through the connector  700  via a connector fluid path  704 P, to a connector outlet port  704 O, and to an incoming fluid port  800 A of the manifold  800 . Fluid flows from the incoming fluid port  800 A, through a fluid inlet path  802  in the manifold  800 , through manifold inlet port  800 I and to the fluid transfer system  900 . In this operational state, fluid leaves the fluid transfer system  900 , passes through the third manifold port  814 , through the third manifold fluid flow path  812  defined in the manifold  800 , through manifold port  800 D, to the third fluid path connector (or port)  718  of the connector  700 , through the third connector fluid path  716 , through connector port  722 , into the fluid container fluid line  402 , and into the fluid container  400 . 
     Some portions or all of the fluid distributor  500  (e.g., including some or all of the connector  700 , manifold  800 , and/or fluid transfer system  900 ) may be included in or engaged with a housing  502  (e.g., including a frame  504  and a cap  506 ). See  FIGS.  2 A and  2 B . The housing  502  may be mounted to the sole structure  104  and/or to the footwear upper  102 . When mounted on a side surface of an article of footwear  100 , e.g., as shown in  FIGS.  2 A,  2 B, and  6 - 7 E , the fluid distributor  500  may be located at a lateral, heel area of the upper  102  and/or sole structure  104 , e.g., to help prevent undesired contact between the user’s feet. The example footwear  100  structures of  FIG.  6 - 7 E  show the sole structure  104  including an upwardly extending base surface  700 S that provides a base for attachment of the fluid distributor  500 . The base surface  700 S may form part of lateral cage component  300 L described above in conjunction with  FIG.  2 B . Fluid lines (e.g., from the foot support bladder  200 , from the fluid container  400 , from the fluid source (e.g., pump(s)  600 H,  600 F), and/or from the external environment  150 ) may extend through this base surface  700 S and/or otherwise may be exposed at this base surface  700 S for engagement with the fluid distributor  500 , as will be described in more detail below. 
     As further shown in  FIG.  6    (and as will be described in more detail below), if desired, the cap  506  of the fluid distributor  500  may include an input system, e.g., one or more switches ( 506 A and  506 B shown in  FIG.  6   ). These switches  506 A and  506 B can function as user inputs, e.g., to allow a user to manually increase (switch  506 A) or decrease (switch  506 B) air pressure in the foot support bladder  200 . User interaction with switches  506 A and  506 B, when present, may activate the fluid distributor  500  and fluid transfer system  900  to move fluid as described with respect to one or more of the operational states above.  FIG.  6    further illustrates that the fluid distributor  500  may include one or more lights  506 L (e.g., one or more LED’s (e.g., 12) around a perimeter of its housing  502 ) within a light guide. These light(s)  506 L may be decorative and/or may allow color variations of the displayed light. In some examples, the light(s)  506 L may provide information, e.g., relating to one or more of: (a) an “on” or “off” status of the fluid distributor  500  (e.g., light(s)  506 L on means powered, light(s)  506 L off means unpowered); (b) foot support pressure and/or other pressure status information of the footwear  100  (e.g., depending on light color and/or flashing indicating maximum pressure, minimum pressure, intermediate pressure(s), etc.); (c) system reset status; (d) factory reset status; (e) powering on, powering off, and/or reboot status; (f) pressure adjustment in progress; (g) an error condition; (h) battery charging status; (i) remaining battery charge status; (j) successful and/or unsuccessful electronic communication status information with the other shoe and/or a mobile computing device (BTLE confirmation status); (k) data download, upload, and/or software update progress or status information; (1) operational state identifying and/or status information; etc. Additionally or alternatively, input data (e.g., from speed and/or distance monitoring device, optionally included with the footwear) may be used to control the lights (e.g., the color(s) of the lights(s)  506 L, the number of light(s)  506 L lit, change in lighting arrangement, the arrangement of lit light(s)  506 L, the sequence of lighting, the animation of the lights, etc.). Such data also may enable the lights to provide information, such as foot speed information, distance run information, acceleration information, workout intensity information, battery life status information, decorative features, etc. Light colors, animations, styles, and the like may differ, e.g., between different shoe models, different shoe types, different shoe colorways, etc. Light “animations” as used herein may include, for example one or more of: displayed light colors; changes in displayed light colors; light blinking or flashing rates; changes in light blinking or flashing rates; the number and/or arrangement of the displayed lights; changes in the number and/or arrangement of the displayed lights; etc. While other options are possible, in the specific example of  FIG.  6   , the lights  506 L form an annular ring around the housing  502  (although the entire annular ring need not be lit at the same time). 
     Accelerometer data, speed and/or distance data, impact force data, and/or other data (e.g., detected by “on-board” foot sensors systems, data from sensors included in apparel, and/or data from an external device (such as a smartphone based speed and/or distance monitoring system)) may be communicated to the fluid flow control system and used, e.g., to automatically adjust foot support bladder  200  pressure. Detected faster speeds and/or acceleration may be used as input(s) to initiate a foot support pressure increase, while detected slower speeds and/or deceleration may be used as input(s) to initiate a foot support pressure decrease. These types of additional input data, input data sources, and/or pressure adjustments may be provided in any of the examples of fluid distributors  500 , fluid flow control systems, fluid transfer systems  900 , foot support systems, sole structures  104 , and/or articles of footwear  100  described in this specification. 
       FIGS.  8 A and  8 B  illustrate another example arrangement of a fluid distributor  500  and/or a foot support system in an article of footwear  100 . As shown in these figures, the fluid container  400  (formed as a fluid-filled bladder in this example) is provided at least in a heel support area of the article of footwear  100  and the foot support bladder  200  is provided at least in a forefoot support area of the article of footwear  200 . The opposite arrangement also is possible. For example, in  FIG.  8 A , the fluid container  400  (e.g., formed as a fluid-filled bladder) may be provided at least in a forefoot support area of the article of footwear  100  and the foot support bladder  200  may be provided at least in a heel support area of the article of footwear  200 . Some portions or all of the fluid distributor  500  (e.g., including some or all of the connector  700 , manifold  800 , and/or fluid transfer system  900 ) may be mounted at a rear heel area of the article of footwear  100 . The fluid distributor  500  in this example is engaged with the upper  102 , although it may be engaged, at least in part, with the sole structure  104  at the rear heel area, if desired. Additionally or alternatively, as shown in  FIG.  9   , if desired, at least a portion of the fluid distributor  500  may be releasably secured (see arrow  508 ) within a receptacle  510  provided on the footwear  100  structure (e.g., as part of the sole structure  104  and/or upper  102 , such as a heel counter type component). If necessary or desired, a locking mechanism (e.g., releasable retaining flap  512 ) may be used to hold the fluid distributor  500  in place with respect to the receptacle  510 . Any desired manner of releasably securing the fluid distributor  500  in the receptacle  510  may be used without departing from this technology. 
       FIG.  10    provides a block diagram illustrating features of assembly of an example article of footwear  100  (e.g., including a sole structure  104  like that shown in  FIG.  2 B ), including inclusion of a fluid distributor  500  or fluid flow control system in accordance with some aspects of this technology. In addition to the various components and parts described above,  FIG.  10    provides additional information as to how the components and/or parts may be engaged together. Examples include the use of primers and adhesives, snap fit parts, retention clips, RF welds, and direct tube connections. Any desired manner of engaging the various components and/or parts together may be used without departing from this technology, including connectors, adhesives, and the like as are conventionally known and used in the footwear arts. 
     In some examples of this technology, the fluid distributor  500  may have a configuration like that shown in  FIGS.  11 A and  11 B  (note also the discussion of  FIGS.  5 A- 5 F  above). In this example, the connector  700  includes a filter  702  that accepts fluid from the external environment (e.g., via inlet port  702 I). The connector  700  forms a separate part that is engaged with a housing  750 , and the manifold  800  and fluid transfer system  900  are contained within housing  750 . The connector  700  of this example connects with four external fluid lines (e.g., flexible tubes). One fluid line  604  takes incoming fluid from the external environment, via connector inlet port  702 I and outlet port  702 O, to the pump(s) ( 600 H,  600 F). A second fluid line  606  takes fluid from the pump(s) ( 600 H,  600 F) back to the connector  700  so it can be introduced into the manifold  800  and fluid transfer system  900  under increased pressure from the pump(s)  600 H,  600 F. A third fluid line  202  extends to and is in fluid communication with the foot support bladder  200 . This fluid line  202  is used to move fluid into the foot support bladder  200  from the fluid distributor  500  and out of the foot support bladder  200  into the fluid distributor  500 . A fourth fluid line  402   extends to and is in fluid communication with the fluid container  400 . This fluid line  402  is used to move fluid into the fluid container  400  from the fluid distributor  500  and out of the fluid container  400  into the fluid distributor  500 . Notably, as shown in  FIGS.  11 A and  11 B , the ports  702 O,  704 ,  720 , and  722  of connector  700  connecting with external fluid lines  604 ,  606 ,  202 , and  402 , respectively, may be aligned along one surface  704 S of the connector  700  (and extend, at least in part, in parallel through the connector  700 , if desired). 
       FIGS.  11 A and  11 B  further illustrate that the housing  750  for the manifold  800  and fluid transfer system  900  of this example includes four ports:  800 A,  800 B,  800 C, and  800 D. Port  800 A of this example connects with port  704 O on the connector  700  body in fluid communication with fluid line  704 P to accept incoming fluid from fluid line  606  (and thus from the pump(s) ( 600 H,  600 F)) and takes the incoming fluid into the manifold  800  and/or fluid transfer system  900 . Port  800 B of this example connects with port  706  on the connector  700  body and exhausts excess or undesired fluid back to the external environment (e.g., through the connector  700  body). Port  800 C of this example connects with port  712  on the connector  700  body and exchanges fluid (in either direction) between the foot support bladder  200  and the manifold  800 . Port  800 D of this example connects with port  718  on the connector  700  body and exchanges fluid (in either direction) between the fluid container  400  and the manifold  800 . Notably, as shown in  FIGS.  11 A and  11 B , the ports  800 A,  800 B,  800 C, and  800 D of manifold  800  may be aligned along one surface  750 A of the housing  750  and/or of the manifold  800  (and may extend, at least in part, in parallel through the housing  750  and/or the manifold  800 , if desired). Connector  700  ports  704 O,  706 ,  712 , and  718  (which connect with manifold ports  800 A,  800 B,  800 C, and  800 D, respectively) may be aligned along one surface  704 S of the connector  700  (and extend, at least in part, in parallel through the connector  700 , if desired). In this illustrated example, connector  700  ports  704 O,  706 ,  712 , and  718  may be located somewhat below and offset from connector ports  704 ,  702 O,  720 , and  722 , respectively, on surface  704 B of the connector  700 . Surfaces  704 S and  704 B may constitute a common surface on the connector  700 , may be offset from one another, may be different from one another, may face in different directions, etc. 
       FIG.  11 B  further illustrates that one or more of the connector fluid paths  704 P,  714 ,  716  may define a bent or curved path. One or more connector fluid paths  704 P,  714 ,  716  may include: (a) a first axial direction  700 AX 1 , (b) a second axial direction  700 AX 2 , and (c) a connecting portion  700 CP joining the first axial direction  700 AX 1  and the second axial direction  700 AX 2 . The first axial direction  700 AX 1  and the second axial direction  700 AX 2  extend away from one another from the connecting portion  700 CP at an angle of 70 degrees or less. 
     As further shown in  FIGS.  11 A and  11 B , the connector  700  of this example includes fluid paths  704 P,  714 ,  716  that pass through the connector body to connect connector ports  704 ,  720 ,  722  with manifold ports  800 A,  800 C,  800 D. The fluid paths  704 P,  714 ,  716  form a bent or curved path through the connector  700  body in this example. Fluid may enter and exit the connector  700  from the same general side of the connector  700  and/or in the same general direction (e.g., as shown in  FIG.  11 B ). 
       FIGS.  12 A- 12 C  further illustrate the connector  700 -to-housing  750  connection of  FIGS.  11 A and  11 B  to highlight some additional potential features. As shown in these figures, a sealing system  760  is provided between the ports  800 A,  800 B,  800 C,  800 D of manifold  800  and the ports,  704 O,  706 ,  712 ,  718 , respectively, of connector  700 . The sealing system  760  includes female engagement parts (e.g., channels  760 A,  760 B,  760 C,  760 D) that fit around male engagement parts (e.g., tubular structures forming the outer surfaces of ports  800 A,  800 B,  800 C,  800 D) to sealingly engage the manifold  800  with the connector  700 . The other ends of channels  760 A,  760 B,  760 C,  760 D may sealingly engage the connector  700  and align with (and/or form) connector ports  704 O,  706 ,  712 ,  718 . 
       FIGS.  13 A- 13 C  illustrate a different connection between the housing  750  and the external fluid lines  202 ,  402 ,  604 ,  606 . In this example, the connector  700  is not a separate part engaged with manifold  800 , but rather the connector  700  constitutes part of the manifold  800  and/or is fixed in housing  750 . In this connection, the ends of fluid lines  202 ,  402 ,  604 ,  606  form male connector parts that extend into female openings forming the ports  704 ,  702 O,  720 ,  722  of the connector  700  portion of manifold  800 . In this structure, fluid enters and exits the connector  700  from different sides or surfaces  704 S,  704 B of the connector  700  and/or in different directions. Thus, the connector  700 -to-housing  750   connections shown in  FIGS.  13 A- 13 C  follow a different path shape than the connector  700 -to-housing  750  fluid flow path shapes shown in  FIGS.  11 A- 12 C  (i.e., connector fluid paths  704 P,  714 ,  716  differ in shape in these examples).  FIGS.  13 A- 13 C  further show fluid lines  202 ,  402 ,  604 ,  606  (which extend from internal locations within the article of footwear  100 ) secured to the outer surface  750 S of housing  750  by one or more retainer clips  752  (one clip  752  shown in  FIGS.  13 A- 13 C  engaging all of fluid lines  202 ,  402 ,  604 ,  606 ). The retainer clip(s)  752  helps hold the fluid lines  202 ,  402 ,  604 ,  606  in place with respect to the housing  750 , which can help prevent kinks, disconnections, etc. and/or assist with assembly. The retainer clip(s)  752  may be engaged with housing  750  in any desired manner, including via retaining structures  754  and friction fit, releasable engagements, fixed engagements, adhesives, mechanical connectors, etc. 
       FIGS.  14 A and  14 B  illustrate features of engaging a fluid distributor  500  according to some aspects of this technology with an article of footwear  100  or a component thereof (such as part of a sole structure  104 ). Referring back to the example of  FIGS.  2 A and  2 B , the fluid distributor  500  of that example was engaged with a lateral cage component  300 L of a sole structure  104 . The fluid distributor  500  of this example includes housing  750  that contains at least the manifold  800  and fluid transfer system  900  (optionally engaged with connector  700  as described above). The frame  504  may be engaged or integrally formed with the cage component  300 L or other sole  104  and/or upper  102  component in any desired manner, e.g., such as adhesives, mechanical connectors, 3D printing, etc. Once the housing  750  is engaged with the connector  700  and/or the connector  700  is engaged with the external fluid lines (e.g., as described above and in more detail below), the housing  750  may be engaged within the recess  504 R of the frame  504  and fixed to it (in a permanently fixed or releasable manner). In the illustrated example, housing  750  is engaged with sidewalls  504 W of the frame  504  by retaining elements  750 R extending and fitting into retaining recesses  504 A provided in the interior of sidewalls  504 W of frame  504 . A pressure sensitive adhesive (“PSA”)  770  may be applied to the top surface of the housing  750  and/or the bottom interior surface of the cap  506  to help hold these parts together. Additionally or alternatively, the cap  506  may be engaged (permanently or releasably) with sidewalls  504 W of the frame  504 , e.g., by retaining elements  506 R extending and fitting into retaining recesses  504 B provided in the exterior of sidewalls  504 W of frame  504 . The retaining element(s)  506 R of cap  506 , when present, may be made from a polyether based thermoplastic polyurethane material having good low temperature flexibility and damping characteristics (e.g., to reduce rattling of the cap  506  on the frame  504 ). 
       FIGS.  15 A- 15 C  further illustrate an example of incorporating a fluid distributor  500  into a footwear structure (e.g., into a footwear sole structure  104 ) in accordance with some examples of this technology. The connection shown in  FIGS.  15 A- 15 C  relates to a system having a housing  750  containing the manifold  800  and fluid transfer system  900  engaged with a separate connector  700  structure, e.g., as shown in  FIGS.  11 A- 12 C . As shown in  FIG.  15 A , first the fluid lines from the various footwear component parts are brought to and engaged with connector  700 . In this example, these fluid lines include: (a) fluid line  604  extending from the connector inlet  702 I to the pump(s)  600 H,  600 F, (b) fluid line  606  extending from the pump(s)  600 H,  600 F back to the connector  700 , (c) fluid line  202  extending between the foot support bladder  200  and the connector  700 , and (d) fluid line  402  extending between the fluid container  400  and the connector  700 . Fluid lines  604 ,  606 ,  202 ,  402  may be engaged with their respective connector ports  702 O,  704 ,  720 ,  722  in any desired manner, including via use of adhesives, mechanical connectors, friction fits, engaged male/female connectors, etc. 
     Then, as shown in  FIGS.  15 A and  15 B , the housing  750  including the manifold  800  and the fluid transfer system  900  may be engaged with the connector  700  (e.g., to form the complete fluid distributor  500  of this example). This may occur, for example, by sliding manifold ports  800 A,  800 B,  800 C,  800 D into fluid communication with connector fluid paths  704 P,  708 ,  714 ,  716 , respectively at connector ports  704 O,  706 ,  712 ,  718 , respectively. Note the discussion above relating to  FIGS.  5 A- 5 F and  11 A- 12 C . While not a requirement, this illustrated example includes the sealing system  760  having channels  760 A- 760 D receiving male ports  800 A- 800 D, respectively, of manifold  800 . If necessary or desired, an adhesive may be applied to the manifold ports  800 A,  800 B,  800 C,  800 D, the connector  700  ports  704 O,  706 ,  712 ,  718 , and/or (when present) the sealing channels  760 A,  760 B,  760 C,  760 D to fix the connecting parts together. 
     As shown in  FIGS.  15 A and  15 B , as the housing  750  is being engaged with the connector  700  (in housing recess  750 B), the housing  750 —with engaged connector  700 —may be moved into the recess  504 R of the frame  504  so that the housing  750  engages frame  504  in the manner described above in conjunction with  FIGS.  14 A and  14 B  (e.g., snap fit into place, adhesively bonded, mechanical connectors, etc.). Then, as shown by a comparison of  FIGS.  15 B and  15 C , the cap  506  may be engaged with the housing  750  and/or frame  504 , e.g., in the manner described above in conjunction with  FIGS.  14 A and  14 B  (e.g., snap fit into place, adhesively bonded with pressure sensitive adhesive  770 , mechanical connectors, etc.).  FIG.  15 C  shows the final assembled sole component  104  of this example. The sole component  104  may be engaged with an upper  102  to form the overall article of footwear  100  (before or after the housing  750  is engaged in the frame  504 ). 
       FIGS.  15 D- 15 G  illustrate assembly of a connection in which the connector  700  is formed as part of the manifold  800  structure and included in housing  750  prior to assembly. As shown in  FIGS.  15 D and  15 E , first the fluid lines from the various footwear component parts are brought to and engaged with connector  700  ports located at the interior side of housing  750 . In this example, these fluid lines include: (a) fluid line  604  extending from the connector inlet  702 I to the pump(s)  600 H,  600 F, (b) fluid line  606  extending from the pump(s)  600 H,  600 F back to the connector  700 , (c) fluid line  202  extending between the foot support bladder  200  and the connector  700 , and (d) fluid line  402  extending between the fluid container  400  and the connector  700 . The fluid lines  604 ,  606 ,  202 ,  402  may be engaged with their respective connector ports  702 O,  704 ,  720 ,  722  in any desired manner, including via use of adhesives, mechanical connectors, friction fits, etc. The ends of fluid lines  604 ,  606 ,  202 ,  402  of this example constitute or include female type connectors that fit over male type individual connectors provided with connector ports  702 O,  704 ,  720 ,  722 . Alternatively, the ends of  604 ,  606 ,  202 ,  402  may constitute or include male type connectors and fit within female type individual connectors provided with connector ports  702 O,  704 ,  720 ,  722 . Not all connections on an individual fluid distributor  500  need to be the same type and/or structure. 
     As shown in  FIGS.  15 D and  15 F , after the fluid lines  604 ,  606 ,  402 ,  202  are engaged with the connector  700 , the housing  750  may be moved into the recess  504 R of the frame  504  so that the housing  750  engages frame  504 , e.g., in the manner described above in conjunction with  FIGS.  14 A and  14 B  (e.g., snap fit into place, adhesively bonded, mechanical connectors, etc.). Then, as shown by a comparison of  FIGS.  15 F and  15 G , the cap  506  may be engaged with the housing  750  and/or frame  504 , e.g., in the manner described above in conjunction with  FIGS.  14 A and  14 B  (e.g., snap fit into place, adhesively bonded with pressure sensitive adhesive  770 , mechanical connectors, etc.).  FIG.  15 G  shows the final assembled sole component  104  of this example. The sole component  104  may be engaged with an upper  102  to form the overall article of footwear  100  (before or after the housing  750  is engaged in the frame  504 ). 
     Fluid flow control systems (e.g., fluid distributor  500  and/or portions thereof), foot support systems including such fluid flow control systems, and/or articles of footwear  100  in accordance with aspects of this technology may require a power source, e.g., for powering various components. Components that may require power may include, but are not necessarily limited to, one or more of: a user input system; systems for changing pressure within one or both of the foot support bladder  200  and/or the fluid container  400 ; a system for driving and/or controlling the fluid transfer system  900 ; the lights  506 L (if present); accelerometers and/or other sensors; pumps; compressors; etc. In at least some examples of this technology, the power source may include a rechargeable battery contained in housing  750 .  FIGS.  16 A- 21 C  illustrate various examples of systems (e.g., wireless systems) for recharging a battery in accordance with some examples of this technology. As one example,  FIGS.  16 A- 16 C  show a charge puck  1102  that may be engaged with an AC adapter  1110  (e.g., via power lines  1104  and  1108 ). The charge puck  1102  includes a magnet  1106  that engages with the shoe  100  at a charging station  502 C. The charging station  502 C (which may be included as part of the fluid distributor  500 ) includes a receiver coil  514  that operatively engages the transmitter coil of the charge puck  1102  to wirelessly recharge the battery in conventional manners (e.g., inductive coupling) as are known and used in the relevant art.  FIG.  16 A  shows charge puck  1102  engagable at a rear heel area of the shoe  100 .  FIGS.  16 B and  16 C  show charge puck  1102  engaged at a side (e.g., lateral, heel side) of shoe  100 .  FIG.  16 B  further illustrates a pair of charge pucks  1102  including individual power lines  1104  engaged with a connector  1108 A that extends to a single power line  1108  coupled with AC adapter  1110 . Rather than rechargeable batteries, some examples of this technology may use non-rechargeable batteries. 
       FIGS.  17 A and  17 B  illustrate other examples of charge pucks  1102 A and  1102 B that may be used in some examples of this technology. Charge puck  1102 A of  FIG.  17 A  includes plural magnets  1106  arranged around an annular transmitter coil  1112  to magnetically engage charge puck  1102 A with the charging station  502 C magnet. Charge puck  1102 B of  FIG.  17 B  includes a central magnet  1106  that has an annular transmitter coil  1112  arranged around it. 
       FIGS.  18 A- 18 C  show various manners in which a receiver coil  514  may be incorporated into a fluid distributor  500 , e.g., of the types described above (such as beneath or as part of cap  506 ). The fluid distributor  500  (e.g., its housing  750 , cap  506 , etc.) includes a magnet  520  to releasably couple the charging puck (e.g.,  1102 ,  1102 A,  1102 B, another structure) for inductive coupling and charging. Receiver coil  514  is included to operatively couple to a transmitter coil in the charging puck for inductive charging. A housing  522  (such as a portion of housing  750 , cap  506 , etc.) may prevent direct contact between the receiver coil  514  and the charging puck  1102 ,  1102 A,  1102 B. Electrical output generated by the receiver coil  514  (due to interaction with the transmitter coil in the charge puck) can be used to charge a rechargeable battery, e.g., in ways that are known and used in various arts. 
       FIGS.  18 B and  18 C  show alternative structures for an inductive charging system in fluid distributor  500  (e.g., beneath cap  506 ).  FIG.  18 B  shows the receiver coil  514  separated from printed circuit board  526  with a thin layer of ferrite  524  (e.g., an annular ring of ferrite  524 ).  FIG.  18 C  shows an additional and/or a thicker layer of ferrite  524 , including ferrite  524  extending beneath the magnet  520  and separating the magnet  520  from the printed circuit board  526 . The additional ferrite  524  of the example of  FIG.  18 C  helps shield the charging system from the printed circuit board  526  and/or helps prevent overheating. The additional ferrite  524  of the example of  FIG.  18 C  also may help prevent the magnet(s)  520  from interfering with operation of solenoids, e.g., for fluid transfer systems  900  and/or fluid distributors  500  that include solenoids. Alternatively, if desired, rechargeable batteries that rely on direct electrical contact between the power source and battery may be used (rather than inductive charging systems). 
     One or both shoes  100  of a pair may require a power source and thus may include a rechargeable battery for operating various components of the fluid distributor  500 .  FIGS.  19 A- 21 C  illustrate various examples of charging systems for a pair of shoes  100 .  FIGS.  19 A- 19 D  illustrate an example system  1900  for simultaneously charging a pair of shoes  100 L and  100 R using wireless charging. In this illustrated example, the charging system  1900  resembles a pair of wired earbuds, with a charging puck  1902 L and  1902 R for each shoe  100 L,  100 R, respectively. Wires  1904  from the charging pucks  1902 L,  1902 R (which may be located within an insulating outer cover as is known in the relevant arts) meet at an intermediate connector  1906 , and a wire  1908  extends from the connector  1906  to an AC power adapter  1910 . The term “wire” as used herein in the context of recharging systems for the footwear  100  means any type of electrical connector, including single wires, multiple wires, cables, conductive tracks or tracings, etc. The connector  1906  may distribute power to the two separate wires  1904 , one going to each charging puck  1902 L,  1902 R.  FIG.  19 A  shows the charging pucks  1902 L,  1902 R engaged with the fluid distributor  500  on the lateral sides of each of the left shoe  100 L and the right shoe  100 R, respectively.  FIGS.  19 B and  19 C  show the charging system  1900  parts for storage or travel, both without the AC power adapter  1910  ( FIG.  19 B ) and with the AC power adapter  1910  ( FIG.  19 C ). While other options are possible, as shown in these figures, power wire  1908  may terminate at a USB connector component  1912  and the AC power adapter  1910  may include a port for receiving the USB connector component  1912 . Further, as shown in  FIG.  19 D , in this system, the power wire  1904  engages the body of the puck  1902 L,  1902 R through the side surface  1902 S of the puck  1902 L,  1902 R. 
       FIGS.  19 B and  19 C  further show that, for storage, the magnets of the charging pucks  1902 L,  1902 R may engage with a magnet or magnetic attracting material in the connector  1906  and/or the AC power adapter  1910 . In this manner, the charging pucks  1902 L,  1902 R are releasably fixed to the connector  1906  and/or the AC power adapter  1910  by magnetic engagement and forces, e.g., for storage or travel. If necessary, a magnet or magnetic attracting material may be incorporated into the connector  1906  and/or the AC power adapter  1910  (e.g., to internal or external side surfaces of the connector  1906  and/or the AC power adapter  1910 ) to facilitate this magnetic attractive engagement. Potential locations for magnet or magnetic attracting material the connector  1906  and/or the AC power adapter  1910  for this purpose are shown schematically as broken lines  1914  in  FIGS.  19 B and  19 C  (e.g., provided as one or more small metal plates, panels, rings, etc.). Alternatively, if desired, the two charging pucks  1902 L,  1902 R may engage one another by the magnets included therein. As another option or alternative, if desired, a separate cover may be provided, including, a magnet or magnetic attracting material therein, and the magnets of the charging pucks  1902 L,  1902 R may engage the cover. The cover may constitute a cover or container for holding the AC power adapter  1910 , the connector  1106 , and/or the overall charging system  1900 . 
       FIGS.  19 E- 19 G  show a similar “wired earbud” style charging system  1950  to that described above in conjunction with  FIGS.  19 A- 19 D . Rather than the pucks  1902 L,  1902 R, however, the charging connectors  1952 L and  1952 R are shaped more akin to paddles. More specifically, a rigid plastic “handle”  1960  extends rearward from the charging base  1962 , and the wires  1954  from the charging base  1962  extend through the handle  1960 . The wires  1954  from each charging connector  1952 L,  1952 R (which may be located within an insulating outer cover as is known in the relevant arts) meet at an intermediate connector  1956 , and a wire  1958  extends from the connector  1956  to an AC power adapter  1910 . The connector  1956  may distribute power to the two separate wires  1954 , one going to each charging connector  1952 L,  1952 R.  FIG.  19 E  shows the charging connectors  1952 L,  1952 R engaged with the fluid distributor  500  on the lateral sides of each of the left shoe  100 L and the right shoe  100 R, respectively.  FIGS.  19 F and  19 G  show the charging system  1950  parts for storage or travel, both without the AC power adapter  1910  ( FIG.  19 F ) and with the AC power adapter  1910  ( FIG.  19 G ). The charging system  1950  of  FIGS.  19 E- 19 G  may include a magnet or magnetic attracting material  1914  in the AC power adapter  1910 , e.g., in the same manner described above with respect to  FIGS.  19 B and  19 C . 
       FIGS.  19 E and  19 F  further show that intermediate connector  1956  may releasably connect to wires  1954 , e.g., by end  1956 A from wire  1958  engaging ends  1954 A of wires  1954 . When releasable, any desired type of releasable electrical connection may be used, including sockets, plugs, clips, and/or other releasable connections as are known and used in the relevant arts.  FIG.  19 F  further shows charging connectors  1952 L,  1952 R directly and magnetically engaged with one another for storage or travel by the magnets included in them. Additionally, the wires  1954 ,  1958  may wrap around handles  1960  in a compact manner for storage or travel, e.g., as shown in  FIG.  19 F . 
       FIGS.  20 A- 20 D  illustrate another example system  2000  for simultaneously charging a pair of shoes  100 L and  100 R using wireless charging, e.g., of the various types described above. In this illustrated example, the charging system  2000  resembles a pair of headphones, with a charging puck  2002 L and  2002 R for each shoe  100 L,  100 R, respectively. Wires from the charging pucks  2002 L,  2002 R extend through the interior of a flexible connector  2004  having a normally arched structure. The wires from the charging pucks  2002 L,  2002 R connect to a wire  2008  that extends from the arched connector  2004  to an AC power adapter  2010 . Internal circuitry and/or switching within arched connector  2004  may distribute power to the two charging pucks  2002 L,  2002 R.  FIG.  20 A  shows charging puck  2002 L engaged with the fluid distributor  500  on the lateral side of left shoe  100 L and charging puck  2002 R engaged with the fluid distributor  500  on the lateral side of right shoe  100 R.  FIGS.  20 B and  20 C  show the charging system  2000  parts for storage or travel, both without the AC power source  2010  ( FIG.  20 B ) and with the AC power source  2010  ( FIG.  20 C ). Further, as shown in  FIGS.  20 A and  20 D , in this system  2000 , the arched connector  2004  engages the side (and/or top) surface of the body of the puck  2002 L,  2002 R.  FIG.  20 B  further shows charging connectors  2002 L,  2002 R directly engaged with one another for storage or travel by the magnets included in them. Additionally or alternatively, if desired, the charging system  2000  of  FIGS.  20 A- 20 D  may include a magnet or magnetic attracting material  1914  in the AC power adapter  2010 , e.g., in the same manner described above with respect to  FIGS.  19 B and  19 C . 
       FIGS.  21 A- 21 D  illustrate another example system  2100  for simultaneously charging a pair of shoes  100 L and  100 R using wireless charging, e.g., of the various types described above. In this illustrated example, the charging system  2100  includes a charging puck  2102 L and  2102 R for each shoe  100 L,  100 R, respectively. A wire  2108  from an AC power adapter  2110  connects to one of the charging pucks (puck  2102 R in this illustrated example), and another wire  2104  extends from that charging puck to the other charging puck ( 2102 L in this illustrated example). Thus, as shown in  FIG.  21 D , circuitry within charging puck  2102 R splits incoming power from wire  2108 : (a) to be used for charging at puck  2102 R and (b) to pass through puck  2102 R to wire  2104  and to puck  2102 L. Thus, the wires  2108  and  2014  connect charging pucks  2102 R,  2102 L in series.  FIG.  21 A  shows the charging puck  2102 R engaged with the fluid distributor  500  on the lateral side of right shoe  100 R and the connection of charging puck  2102 L with the lateral side of left shoe  100 L.  FIGS.  21 B and  21 C  show the charging system  2100  parts for storage or travel, both without the AC power adapter  2110  ( FIG.  21 B ) and with the AC power adapter  2110  ( FIG.  21 C ).  FIG.  21 B  further shows charging connectors  2102 L,  2102 R directly engaged with one another for storage or travel by the magnets included in them. Additionally or alternatively, if desired, the charging system  2100  of  FIGS.  21 A- 21 D  may include a magnet or magnetic attracting material  1914  in the AC power adapter  2110 , e.g., in the same manner described above with respect to  FIGS.  19 B and  19 C . 
       FIGS.  21 B and  21 C  further show a different connector  2112  between wire  2108  and AC power adapter  2110 . Connector  2112  includes a mechanical connector to make electrical connection with a corresponding connector provided on the power adapter  2110  (e.g., a plug type connection). Any desired type of connection between connector  2112  (as well as the other connectors described above in  FIGS.  19 A- 20 D ) and its corresponding AC power adapter  2110  can be used without departing from this technology, including fixed electrical connections, releasable electrical connections, USB plug connections, and/or other suitable plugs, sockets, clips, and/or electrical connections as are known and used in the relevant rechargeable electronic and electrical device arts. 
     As mentioned above, the fluid distributor  500  (e.g., including housing  502  made from a rigid plastic material) may include one or more buttons  506 A,  506 B, e.g., used as user input for changing/controlling pressure in the foot support bladder  200  (and/or other portions of the footwear  100 ). The fluid distributor  500  also may include one or more lights  506 L, e.g., as decoration and/or to indicate some status information about the footwear  100  and/or the overall system as described above.  FIGS.  22 A- 22 E  provide additional information regarding potential examples of a user interface switch or system  2200  for unlocking the user interface switch or system  2200  and/or changing the pressure in some portion of the foot support system. The “keep-out” zone shown in  FIG.  22 A  corresponds with an area of the housing  502  that includes the coil for magnetic charging as described above (“keep-out” meaning that the “real estate” beneath that area already is claimed for the coil or other structures, and thus cannot house circuitry and/or components for user interface switch  2200 ). 
       FIG.  22 A  provides a chart of various options for unlocking and using user interface switch or system  2200  and its operation.  FIGS.  22 B- 22 E  provide views of potential structures for such input systems (with Example 4 from  FIG.  22 A  particularly illustrated). In  FIG.  22 A , Example 1, the button is a capacitive type button (e.g., detecting a user’s finger touch by capacitive coupling of structures as is known and used in relevant arts). This example user interface switch or system  2200  is unlocked by a swipe action of the button, and changes in pressure also are input by a swipe action (e.g., swipe right (toward  506 B in  FIG.  22 B ) to decrease pressure by a predetermined amount or step, swipe left (toward  506 A in  FIG.  22 B ) to increase pressure by a predetermined amount or step). A single swipe could be used to both unlock the user interface switch or system  2200  and introduce pressure change input. For example, the initial “touch” and beginning of the swipe could unlock (and if needed, wake up) the user interface switch or system  2200 , and the continuing swiping action (left or right) could provide the pressure change input. Additionally or alternatively, two swipes may be used or required, e.g., the first to unlock and/or wake up the user interface switch or system  2200  and the second to provide the pressure change input. 
     In  FIG.  22 A , Example 2, the button is a capacitive type button (e.g., including a capacitive sense electrode of structure known and used in art relevant arts). This example user interface switch or system  2200  is unlocked by a swipe action of the button, and changes in pressure are input by a touch action on either side of the center (e.g., touch the right side  506 B to decrease pressure by a predetermined amount, touch the left side  506 A left to increase pressure by a predetermined amount). 
     In  FIG.  22 A , each of Examples 3 and 4 illustrates structure for two potential input options. As one option in each of Examples 3 and 4 (the top options shown in the table), the buttons  2200 A,  2200 B may be physical buttons (also called “tactile buttons” herein) that require two physical presses-one press to unlock the user interface switch or system  2200  and another press to enter the desired pressure increase or pressure decrease information. As another option (the bottom options of Examples 3 and 4 shown in the Table), the buttons  2200 A,  2200 B may be a combination of a capacitive touch button (used to unlock the user interface switch or system  2200 ) and a tactile button (used to change pressure setting). In these bottom options of Examples 3 and 4, the systems operate by (a) an initial “touch” action to unlock and/or wake up the user interface switch or system  2200  and then (b) a button press action (at buttons  2200 A,  2200 B) to change pressure settings. One difference between the buttons of  FIG.  22 A  Examples 3 and 4 relates to the locations of the buttons  2200 A,  2200 B with respect to the “keep-out” zone. In Example 3, the buttons  2200 A,  2200 B are adjacent one another on the same side of the button and the same side of the keep-out zone. In Example 4, the buttons  2200 A,  2200 B are separated from one another by the keep-out zone and are on different ends of the button. Buttons having a “button press” or “press” label in  FIG.  22 A  may constitute physical switch type button activators. 
     The tactile buttons (e.g., of structure known and used in the relevant art) may have an outer surface providing a distinct tactile feel. As one example, the exposed pressing surface of one button (e.g., pressure increase button  2200 A) may have a convex outer surface and the exposed pressing surface of the other button (e.g., pressure decrease button  2200 B) may have a concave surface. As another option, as shown in  FIG.  6   , one side of the button  506  may be marked with a recessed or raised “plus” sign (“+”) and the other side may be marked with a recessed or raised “minus” sign (“-”) to provide the distinct tactile feel. In this manner, the user can more easily locate and interact with the correct button, even while wearing the shoes, to make desired pressure changes. 
       FIGS.  22 B- 22 E  provide various views of an example button construction for the “touch/press” option of Example 4 of  FIG.  22 A .  FIG.  22 B  shows flex areas  2202 A,  2202 B corresponding to the physical tactile button locations  2200 A,  2200 B overmolded by a rubber or other polymer (e.g., silicone or other elastomer) composition (or formed in a two-shot molding process). Grooves  2204 A and  2204 B extending partially through the overmold material  2210  around the button actuator area create a thinner layer of rubber or other material (e.g., elastomer) to better enable flexion when buttons  2200 A,  2200 B are pushed. These grooves  2204 A,  2204 B also may provide the tactile feel features described above. Flex areas  2202 A,  2202 B may include a base portion having elastomer overmold material of a first thickness (e.g., 2 mm to 10 mm thick) and the grooves  2204 A,  2204 B may have a second thickness (e.g., 0.5 mm to 3 mm thick) that is less than the first thickness. The first thickness of the overmold material at the base portion may be from 1.5 to 20 times thicker than the second thickness of overmold material in the grooves  2204 A,  2204 B. 
     In this example, when buttons  2200 A,  2200 B are pressed, the overmold material in the grooves  2204 A,  2204 B stretches somewhat under the applied force. As force from the button push is reduced or removed, the stretched material in grooves  2204 A,  2204 B returns toward its unstretched configuration, providing return energy. This return energy may provide an interesting tactile feel on the user’s finger, somewhat of a “bouncy” or “trampoline” effect. The overmold material  2210  also closes the button area to help prevent water, debris, or other undesirable material from entering the interior of housing  502 . The flex areas  2202 A,  2202 B may be formed as part of the cap  506  placed over the housing  750  of the fluid distributor  500  and/or as the top surface of the housing  750  of the fluid distributor  500 . If desired, however, grooves  2204 A and/or  2204 B in the flex areas  2202 A and/or  2202 B may be replaced by through holes. If necessary or desired, in such systems, other sealing components (e.g., elastomer gaskets, O-rings, etc., see  FIG.  22 E ) may be provided to seal off the button openings and/or provide the bouncy” or “trampoline” effect (if desired). 
     The grooves  2204 A and  2204 B in  FIG.  22 B  may have any desired shape(s) without departing from this technology. They may be located adjacent the button actuator areas (e.g., above and/or around the hardware needed to activate the button). In the illustrated example of  FIG.  22 B , the grooves  2204 A and  2204 B are generally U-shaped, having their free or open ends facing one another. The free or open ends could face in other direction(s) as well, including away from one other, toward the other surfaces of the button, etc. In other examples, the grooves  2204 A and/or  2204 B may form closed paths around the button actuator area. 
       FIG.  23    provides an electrical block diagram  2300  of components in some example fluid distributors  500 , fluid flow control systems, sole structures  104 , and/or articles of footwear  100  in accordance with aspects of this technology. While  FIG.  23    illustrates several components and systems incorporated into fluid distributors  500 , fluid flow control systems, sole structures  104 , and/or articles of footwear  100  in accordance with aspects of this technology, any desired subset or combination of these components and systems may be used in some examples of this technology. More of these components and systems identified in  FIG.  23    will be described in more detail below. 
       FIG.  24    illustrates an example layout of various components within a housing  502  (and/or on a circuit board) of a fluid distributor  500  in accordance with at least some examples of this technology.  FIG.  24    shows various lights  506 L arranged around the exterior perimeter of the housing  502 , as mentioned above. A light driver  2410  (“LED driver”) is provided to control operation of the lights  506 L, which may constitute a 12 RGB LED ring of lights (e.g., under programmed/programmable control).  FIG.  24    further shows that this system may include an antenna  2402  (e.g., a Bluetooth Low Energy (“BLE”) antenna) for receiving wireless input (such as from a computing device, mobile computing device (e.g., a “smart phone”)); for receiving electronic information from the other shoe of a pair; for receiving electronic information from apparel and/or another source; for receiving electronic information from other sensors (e.g., on-board shoe sensor(s), apparel based sensors, sensors included as a speed and/or distance monitor in an external computing device, etc.); etc. A microcontroller  2404  (“MCU”) is provided to run the software and hardware needed to perform the functions described above and those described in more detail below (and optionally any other functions and/or hardware that may be provided). One or more inertial measurement units (“IMU’s”)  2406  also may be provided, such as accelerometers (“ACC”), magnetometers (“MAG”), etc., to detect user motion in the article of footwear  100 . Data from such inertial measurement units or other available sensors may be used to automatically control and/or change pressure settings in the foot support bladder  200  and/or fluid container  400  in one or both shoes. A motor driver  2408  is present in this illustrated example, e.g., to control operation of any motor(s) in the fluid distributor  500  (e.g., as will be described in more detail below). The seemingly “open space” within the housing  502  may be filled, at least in part, with some or all of a manifold  800  and fluid transfer system  900 , the rechargeable battery, and/or other desired components. 
       FIG.  25    illustrates several potential avenues of communication between a central controller  2500  and the shoes of a pair (e.g., being worn by a user). These communications may take place via hardware, systems, communication protocols, and the like, as are conventionally known and used in the relevant art. While both shoes of a pair may include all of the hardware and software needed to provide the desired functions (e.g., as described above and/or as described in more detail below), in some examples of this technology, one shoe of a pair may include all of the desired hardware and software (“connected as central” shoe  2502  in  FIG.  25   ), and that shoe  2502  may communicate with the other shoe (“connected as peripheral” shoe  2504  in  FIG.  25   ), e.g., in a wireless manner, via an antenna  2402 . In this manner, the overall hardware costs may be reduced for a pair of shoes by providing less hardware on one shoe. The central controller  2500  may be included as part of one shoe (e.g., within housing  502  of fluid distributor  500  for that shoe), and it may communicate with that shoe via a wired or wireless connection. The shoe including the central controller  2500 , in turn, may communicate with the other shoe, e.g., via a wireless connection as mentioned above. Additionally or alternatively, if desired, the central controller  2500  may be provided as part of a computing device, e.g., a mobile computing device, such as an application program operating on a smartphone. In this manner, pressure change information may be provided via an external computing device (e.g., the smartphone) and transmitted to one or both shoes, e.g., via antenna  2402  in housing  502 . 
       FIG.  25    further illustrates how the various components operate to go into and out of an “asleep” mode  2506 . The component(s) may go into an “asleep” mode  2506 , for example, when no “foot presence sensor” or “FPS” data is received for a predetermined time period for one or both shoes, when the connection is lost from one or both shoes, after a timeout period (e.g., with no foot pressure sensing), etc. Foot presence within a shoe  2502 ,  2504  may be sensed in any desired manner, such as by capacitance sensors, force/pressure sensors, switch type sensors, etc. The components may “awake” from “asleep” mode, e.g., when foot pressure is sensed in at least one shoe  100 , when user interaction with an input device (e.g., input buttons  506 A,  506 B, an application program on a mobile computing device, etc.) is received, etc. Once awakened, the central controller  2500  may be activated to “advertise” an available wireless connection to engage with at least shoe  2502 . The central controller  2500  also may inform the central shoe  2502  that the peripheral shoe  2504  is available and facilitate connection (and optionally act as a connection intermediary) between the central shoe  2502  and the peripheral shoe  2504 . Other component interaction and communication states are shown in  FIG.  25   , e.g., to show when and how the various components may attempt to connect to one another, attempt to maintain connections with one another, and/or attempt to reconnect to one another. 
     In the arrangement shown in  FIG.  25   , the shoes  2502 ,  2504  can communicate directly with one another. Further, in some connection protocols, when in direct communication: (a) either shoe  2502 ,  2504  is capable as functioning as the “central” communication point (providing input and information to the other shoe) and/or the controller  2500  and (b) either shoe  2502 ,  2504  is capable as functioning as the “peripheral” communication point (receiving input and information from the other shoe and/or controller  2500 ). For a given pair of shoes, the same shoe need not always be the central shoe and/or controller  2500  and the same shoe need not always be the peripheral shoe. Further, in some arrangements like those shown in  FIG.  25   , when communication between the shoes  2502 ,  2504  and an external computing device occurs, such as via wireless communication connection with a mobile telephone, smartphone, etc., both shoes  2502 ,  2504  become peripheral devices and the external computing device becomes the central device. The external computing device may include a user input system, e.g., to receive user input via an application program, and transmit this input (e.g., pressure change input) to the relevant shoe or shoes  2502 ,  2504 . 
     In addition, if desired, either shoe  2502 ,  2504  and/or an external communication device in communication with the shoes  2502 ,  2504  may receive data and/or information from and/or transmit data and/or information to one or more electronic devices integrated into apparel  2510  (e.g., motorized fluid containing sports bra (e.g., in which fluid pressure changes alter the support provided, e.g., by a fluid-tight bladder incorporated into the sports bra), motorized fluid containing compression sleeves (e.g., a hollow tubular sleeve comprising a fluid-tight bladder in which fluid pressure in the fluid-tight bladder of the sleeve alters the level of compression provided), apparel having fluid transfer systems (e.g., with fluid-tight bladders) of the types described herein incorporated into them, motorized shoe lacing components, etc.). Thus, either shoe  2502 ,  2504  and/or an external communication device in communication with the shoes  2502 ,  2504  can receive communications from and/or send communications to other components, such as motorized and/or adaptive lacing and support systems in/on the shoe or in/on apparel (e.g., a sports bra, compression sleeve, and the like). When in communication with other such systems provided in apparel  2510 , the apparel  2510  may function as the central communication point with both shoes  2502 ,  2504  as peripherals, or either shoe  2502 ,  2504  may function as the central communication point with the apparel  2510  and other shoe functioning as peripherals. In such systems, however, if an external computing device comes into the communication loop, that device may serve as the central device and both shoes  2502  and any devices included in the apparel  2510  may function as peripheral devices. Further the wireless connection(s) with shoes  2502 ,  2504  may allow connections to any one or more of automatic and/or motorized shoe securing mechanisms, such as motorized laces, or the like. The apparel  2510  may include any part of or all of the electronics, communications capabilities, and/or fluid transfer capabilities as described herein for similar components in footwear. 
     Various examples of structures and operations of fluid transfer systems  900  are described in more detail in the sections that follow. Some aspects of fluid transfer systems  900  in accordance with this technology relate to valve stems within a valve housing to open and close various fluid pathways through a manifold  800 . Other aspects of fluid transfer systems  900  in accordance with this technology relate to solenoid based systems that selectively open and close to control fluid flow through a manifold  800 . 
     B. Valve Stem Based Fluid Transfer System Features 
       FIGS.  26 A- 26 D  provide various views of an example fluid distributor  500  including a movable valve stem type fluid transfer system  900 A in accordance with aspects of this technology. As described above, this example fluid distributor  500  includes a housing  502  in which a manifold  800  and fluid transfer system  900 A are housed as well as a connector  700  that engages the components within housing  502  with a fluid source (e.g., the external environment, pump(s)  600 H,  600 F, a compressor, etc.), the external environment  150 , at least one foot support bladder  200 , and at least one fluid container  400 .  FIGS.  26 A- 26 D  further show the locations of fluid transfer system  900 A and a rechargeable battery  2602  for powering the various electrical or electronic components. 
       FIG.  27 A- 29    provide additional details regarding components of the example manifold  800  and fluid transfer system  900 A in accordance with some aspects of this technology. The manifold  800  of this example includes a manifold body or housing  820 . Referring also to  FIGS.  5 A- 5 F , one surface  822 A or side of manifold body  820  includes ports  800 A,  800 B,  800 C,  800 D having fluid communicating connections with corresponding ports  704 O,  706 ,  712 ,  718 , respectively, of connector  700 . The opposite surface  822 B of manifold body  820  (although it could be another surface) includes inlet port  800 I, first manifold port  804 , second manifold port  808 , and third manifold port  814 . A fluid inlet path  802  extends between port  800 A and fluid inlet port  800 I, a first fluid flow path  806  extends between port  800 B and first manifold port  804 , a second fluid flow path  810  extends between port  800 C and second manifold port  808 , and a third fluid flow path  812  extends between port  800 D and third manifold port  814 . Thus, in this illustrated example, manifold  800  includes four separate fluid pathways extending through it. The manifold  800  of this example further includes at least one pressure sensor (two pressure sensors  850 A,  850 B shown in  FIG.  27 A- 28   ). The pressure sensor(s)  850 A,  850 B may be positioned for determining fluid pressure in at least one of the first fluid flow path  806 , the second fluid flow path  810 , or the third fluid flow path  812 . In some more specific examples, a first pressure sensor  850 A may be provided to determine fluid pressure in the third fluid flow path  812  (and thus in fluid container  400 ), and a second pressure sensor  850 B may be provided for determining fluid pressure in at least one of the first fluid flow path  806  or the second fluid flow path  810  (e.g., the pressure in foot support bladder  200 ). O-rings  852  (or gaskets and/or other appropriate sealing devices) may be provided to sealingly engage the pressure sensor(s)  850 A,  850 B with the manifold body  820 . 
     The fluid transfer system  900 A of this illustrated example includes a valve housing  902  and a valve stem  910  movably (e.g., rotatably, slidingly, etc.) mounted in the valve housing  902 . The valve stem  910  of this example includes a first end  910 A (e.g., a driven end) and a second end  910 B opposite the first end  910 A (e.g., a free end). A perimeter wall  910 W extends between the first end  910 A and the second end  910 B. The first end  910 A, the second end  910 B, and the perimeter wall  910 W define an internal chamber  910 I of the valve stem  910 . Also, the perimeter wall  910 W of the valve stem  910  includes a plurality of through holes  910 H extending from the internal chamber  910 I to an exterior surface of the perimeter wall  910 W and valve stem  910 . As will be described in more detail below (e.g., in conjunction with  FIGS.  30 A- 30 G ), movement of the valve stem  910  to a plurality of positions selectively places this fluid flow control system (e.g., fluid distributor  500 , fluid transfer system  900 A, the combined manifold  800  and fluid transfer system  900 A, etc.) in a plurality of operational states by placing one or more of the plurality of through holes  900 H in fluid communication with the first fluid flow path  806 , the second fluid flow path  810 , and/or the third fluid flow path  812 . 
       FIG.  27 A -29 further illustrate that this example fluid transfer system  900 A includes a drive system (e.g., a motor  920 ) and a transmission  922  (including output gear, nose pin, cup seal, and other gears, described in more detail below). The transmission  922  components transfer power from the motor  920  to the first end  910 A of the valve stem  910  to move (rotate in this example) the valve stem  910  with respect to the valve housing  902  (and manifold  800 ). A power source (e.g., from rechargeable battery  2602 ) and a microcontroller, e.g., provided with the fluid distributor  500  and not shown in  FIG.  27 A -29, selectively drive the motor  920  to position the valve stem  910  in one of the plurality of positions to enable movement of the fluid from the desired starting points to the desired locations. 
     The fluid transfer system  900 A of this example additionally includes an encoder system (e.g., an on-axis magnetic encoder system, an off-axis magnetic encoder system, etc.), including an encoder magnet  932  and an encoder board  934 , for detecting the position (e.g., rotational position) of the valve stem  910  with respect the housing  902  and/or other component parts. The encoder system provides data indicating this position to the microcontroller. Such encoder systems are commercially available and their operation are known in the relevant arts. 
     In this example fluid transfer system  900 A, the valve housing  902  is engaged with the manifold body  820  in a sealed manner. While this sealing can be accomplished in a variety of ways, in this illustrated example, one or more sealing connectors  840  are provided between the perimeter wall  910 W of the valve stem  910  and one or more of fluid inlet port  800 I, first manifold port  804 , second manifold port  808 , and/or third manifold port  814 . Sealing connector  840  extends into recess  902 R on one side of valve housing  902 . In this illustrated example, a single sealing connector  840  or seal block includes three sealing ports  840 A,  840 B,  840 C. Three sealed channels  842 A,  842 B,  842 C through the sealing connector  840  connect with first manifold port  804 , second manifold port  808 , and third manifold port  814 , respectively. In this manner, sealed channels  842 A,  842 B,  842 C are in fluid communication with first fluid flow path  806 , second fluid flow path  810 , and third fluid flow path  812 , respectively, of the manifold body  820 . Additionally or alternatively, if desired, another sealing port and another sealed channel may be provided in sealing connector  840  to connect the manifold  800  fluid inlet port  800 I with the valve housing  902 . In the specific example of  FIG.  29   , however, the fluid inlet path  802  from manifold port  800 A to fluid inlet port  800 I connects directly with valve housing  902 , and a fluid intake path  902 A extends through valve housing  902  to admit incoming fluid into the internal chamber  910 I of valve stem  910  through the open second end  910 B thereof. See fluid pathway  902 P shown in dashed line in  FIG.  29   . 
     As further shown in  FIG.  29   , the first manifold port  804 , the second manifold port  808 , and the third manifold port  814  align along an exterior side of the manifold  800 . Additionally or alternatively, if desired, manifold ports  800 A,  800 B,  800 C,  800 D align along an exterior side of the manifold  800  (and in this illustrated example, on the opposite side of the manifold  800  from ports  804 ,  808 ,  814 ). Any two or more of the fluid flow paths  802 ,  806 ,  810 , and  812  may align and/or extend in parallel through the manifold body  820 . Additionally or alternatively, any two or more of the sealed channels  842 A,  842 B,  842 C of sealing connector  840  may align and/or extend in parallel through the sealing connector  840  body. 
     The valve stem  910  may place the fluid transfer system  900 A in two or more operational states depending on the position of the valve stem  910  with respect to the housing body  902 . Movement of the valve stem  910  changes positioning of the through holes  910 H through the perimeter wall  910 W of the valve stem  910  and allows different holes  910 H to align with the sealing connector  840  ports  840 A,  840 B,  840 C. The valve stem  910  may be moved, e.g., rotated, under control of a microprocessor controlling a motor  920 .  FIGS.  30 A- 30 G  provide additional details about various operational states that may be provided and used in fluid distributor  500 , foot support systems, sole structures  104 , and articles of footwear  100  including fluid transfer system  900 A in accordance with aspects of this technology. This discussion, as shown in  FIG.  29   , assumes: (a) manifold port  800 A is in fluid communication with a fluid source, such as pump(s)  600 H,  600 F (e.g., via connector ports  702 I and  704 O and the components connecting them or other appropriate fluid lines) to bring fluid into the fluid transfer system  900 A; (b) manifold port  800 B is in fluid communication with the external environment  150  (e.g., via connector port  706  and fluid path  708  and/or other appropriate fluid lines) to exhaust any excess fluid in the fluid transfer system  900 A to the external environment  150 ; (c) manifold port  800 C is in fluid communication with a foot support bladder  200  (e.g., via connector ports  712  and  720  and fluid line  714  and/or other components connecting them) to increase or decrease fluid pressure in the foot support bladder  200 ; and (d) manifold port  800 D is in fluid communication with a fluid container  400  (e.g., via connector ports  718  and  722  and fluid line  716  and/or other components connecting them) to increase or decrease fluid pressure in the fluid container  400 . Note also the connections and discussion of operational states shown and discussed in connection with  FIGS.  5 A- 5 F . 
     As described above, in this example fluid distributor  500 , the valve stem  910  is rotated to different positions to place the fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  in different operational states. While any number of operational states may be provided, in this illustrated example, valve stem  910  may be rotated to six distinct operational states as shown in  FIGS.  30 A- 30 G .  FIG.  30 A  schematically illustrates various positions of valve stem  910  as it is rotated clockwise (e.g., from operational state 1 to operational state 6) or counter-clockwise (e.g., from operational state 6 to operational state 1). In some pressure control methods in accordance with aspects of this technology, the “standby” state may be the typical state during most times (when no pressure changes occur). The valve stem  910  rotates the proper amount to go into the desired operational state (e.g., operational states 2-6), waits for the pressure to reach the desired level (as measured by pressure sensor(s)  850 A,  850 B), and then rotates back to the standby state. 
     Operational state 1 of this example is the “standby” or “idle” state in which fluid pumped with each step simply passes through the system, e.g., from pump(s)  600 H,  600 F, through manifold  800 , through fluid transfer system  900 A, back through manifold  800 , and to the external environment  150 . See  FIG.  30 B . Operational state 1 prevents any part of the overall foot support system from becoming over pressurized, e.g., when a foot-activated pump is used and activated in each step to move fluid. 
     Operational state 2 (e.g., with the valve stem  910  rotated 60 degrees clockwise from operational state 1) is a “pumping” state for moving fluid from the pump(s) (or other fluid source) to the foot support bladder  200 . In operational state 2, fluid pumped during a step passes through the system (e.g., from pump(s)  600 H,  600 F, through manifold  800 , through fluid transfer system  900 A, back through manifold  800 ) and into the foot support bladder  200 . See  FIG.  30 C . This operational state may be used to quickly and/or directly increase fluid pressure in the foot support bladder  200  (e.g., a foot support bladder  200  “inflate” configuration). 
     Operational state 3 (e.g., with the valve stem  910  rotated 60 degrees clockwise from operational state 2) is a “live” state for moving fluid from the foot support bladder  200  to the external environment  150 . In operational state 3, fluid passes through the system (e.g., from foot support bladder  200 , through manifold  800 , through fluid transfer system  900 A, back through manifold  800 ) and to external environment  150 . See  FIG.  30 D . This operational state may be used to release fluid and decrease fluid pressure in the foot support bladder  200  (e.g., a foot support bladder  200  “deflate” configuration). 
     Operational state 4 (e.g., with the valve stem  910  rotated 60 degrees clockwise from operational state 3) also is a “live” state for moving fluid from the fluid container  400  to the external environment  150 . In operational state 4, fluid passes through the system (e.g., from fluid container  400 , through manifold  800 , through fluid transfer system  900 A, back through manifold  800 ) and to external environment  150 . See  FIG.  30 E . This operational state may be used to release fluid and decrease fluid pressure in the fluid container  400  (e.g., a fluid container  400  “deflate” configuration). 
     Operational state  5  (e.g., with the valve stem  910  rotated 60 degrees clockwise from operational state 4) also is a “live” state for moving fluid from the fluid container  400  to the foot support bladder  200 . In operational state  5 , fluid passes through the system (e.g., from fluid container  400 , through manifold  800 , through fluid transfer system  900 A, back through manifold  800 ) and to the foot support bladder  200 . See  FIG.  30 F . This operational state may be used to increase fluid pressure in the foot support bladder  200  by moving fluid from the fluid container  400  into the foot support bladder  200  (e.g., a foot support bladder  200  “inflate” configuration). This operational state allows fluid pressure changes in the foot support bladder  200  without the need for the user to take one or more steps to activate a pump  600 H,  600 F (e.g., while the user is standing or sitting still and/or off his/her feet). This operational state also may allow for more controlled and fine-tuned pressure changes in the foot support bladder  200 , e.g., because large pressure spikes resulting from the wearer landing a step or jump are closed off from direct fluid communication with the foot support bladder  200  in this operational state (e.g., because the fluid line  606  from the foot-activated pump(s)  600 H,  600 F is closed). 
     Operational state 6 (e.g., with the valve stem  910  rotated 60 degrees clockwise from operational state  5 ) is a “pumping” state from the pump(s) (or other fluid source) to the fluid container  400 . In operational state 6, fluid passes through the system (e.g., from pump(s)  600 H,  600 F, through manifold  800 , through fluid transfer system  900 A, back through manifold  800 ) and into the fluid container  400 . See  FIG.  30 G . This operational state may be used to quickly and/or directly increase fluid pressure in the fluid container  400  (e.g., a fluid container  400  “inflate” configuration). 
     Some pressure sensing algorithms and methods in accordance with aspects of this technology may rely on sensor input in addition to pressure sensing in the foot support bladder  200  and/or fluid container  400  to determine the operational state to use. For example, data from an accelerometer, foot force sensor, and/or speed and/or distance monitor may be used to determine whether a pressure increase in the foot support bladder  200  should be accomplished by operational state 2 (with fluid transferred from a foot activated pump system  600 H,  600 F) or by operational state  5  (with fluid transferred from the fluid container  400 ). For example, if the user is moving relatively slowly, transfer via operational state 2 may be desirable, particularly if the fluid container  400  is at a relatively low pressure. But if the user is moving fast and/or applying high contact forces on the foot pumps  600 H,  600 F, operational state  5  may be preferred (e.g., to produce more even fluid flow without pressure spikes due to contact of the sole with the ground). Additionally or alternatively, accelerometer, foot force sensor, and/or speed and/or distance monitor data may be used to automatically change operational states, e.g., to increase or decrease foot support pressure in the foot support bladder depending on movement speed, contact force, etc. Still additionally or alternatively, in at least some examples of systems and methods in accordance with this technology, the system can start to “learn” (e.g., identify patterns) how a user moves (e.g., tends to run or exercise at certain time(s) of the day, tends to run on specific types of surfaces, tends to run at varying speeds (e.g., based on a workout program), etc.) and, based on this information, predict and apply changes in operational states to match predicted changes in motion. In this manner, pressure changes to the foot support system may better align to changes in the user’s motion in “real time” or seemingly real time. Alternatively, when linked to a digital coaching system, automatic (or system generated) operational state changes can be aligned to desired changes in movement received from the digital coaching system to match desired performance or to mitigate injury risk, thereby also being a communication system to the user. 
     Additionally or alternatively, if desired, systems and methods in accordance with at least some aspects of this technology may determine and/or use various step metrics, including step-by-step metrics relating to various features of user contact force with the ground and/or user motion (e.g., metrics relating to the user’s running or other motion technique(s)). Such metrics may include one or more of: (a) contact time per foot per step (e.g., using a foot force signal, such as the time period when vertical force applied by the foot is greater than 50N); (b) swing time period per foot per step (e.g., using a foot force signal, such as the time per foot when vertical force applied by the foot is less than 50N until that foot again creates a force greater than 50N); (c) step cadence (e.g., using a foot force signal, such as the inverse of the sum of the contact and swing time for each foot); (d) step length (e.g., using a foot force signal, such as the sum of contact and swing time x average speed); (e) impact (e.g., using a foot force signal, such as the peak rate of rise of the vertical ground reaction force, the active peak of the vertical ground reaction force, etc.); (f) impulse per foot per step (e.g., using a foot force signal, such as the integral of the ground reaction force magnitude during contact); and (g) contact type per foot per step (e.g., using motion capture data, such as foot angle relative to horizontal at the time of foot contact per step, rearfoot contact angle, midfoot contact ankle, forefoot contact angle, etc.). 
     A fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  may have (or may be placed in) any one or more of (and any combination of) these operational states. Some specific examples of this technology may include all six operational states. Alternatively, some specific examples of this technology may include operational states 1, 3,  5 , and 6 or 1, 3, 4,  5 , and 6 (and any desired pressure increases in the foot support bladder  200  are accomplished using fluid supplied from the fluid container  400 ). If necessary or desired, fluid distributors  500 , foot support systems, sole structures  104 , and/or articles of footwear in accordance with some examples of this technology may include a relief valve in fluid communication with the foot support bladder  200  and/or the fluid container  400  (optionally in place of operational states 3 and/or 4, respectively), e.g., to prevent over-pressurization of these components. 
     More details of fluid flow through the fluid distributor  500  including fluid transfer system  900 A now will be described in conjunction with  FIGS.  5 A- 5 F,  29 , and  30 B- 30 G . In operational state 1 shown in  FIGS.  5 A,  29 , and  30 B , at this first rotational position of the valve stem  910 , fluid moves: (a) from the fluid supply (e.g. from external environment  150 , through connector inlet  702 I, through fluid path  702 P, through connector outlet  702 O, through fluid path  604 , through heel pump  600 H, through fluid path  602 , through forefoot pump  600 F, through fluid line  606 ), (b) through the connector inlet port  704 , (c) through connector fluid path  704 P, (d) through connector outlet port  704 O, (e) through manifold port  800 A, (f) through manifold fluid inlet path  802 , (g) through manifold fluid inlet port  800 I, (h) through fluid intake path  902 A, (i) into the open end  910 B of valve stem  910 , (j) through the internal chamber  910 I, (k) through a first through hole  940 A, (1) through sealing port  840 A, (m) through first sealed channel  842 A, (n) through first manifold port  804 , (o) through first manifold fluid flow path  806 , (p) through manifold port  800 B, (q) through first fluid path connector port  706 , (r) through first connector fluid path  708 , and (s) to the external environment  150  (e.g., through the interior space  710  of connector  700 ). If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of these parts (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     In operational state 2 shown in  FIGS.  5 B,  29 , and  30 C , at this second rotational position of the valve stem  910 , fluid moves: (a) from the fluid supply (e.g. from external environment  150 , through connector inlet  702 I, through fluid path  702 P, through connector outlet  702 O, through fluid path  604 , through heel pump  600 H, through fluid path  602 , through forefoot pump  600 F, through fluid line  606 ), (b) through the connector inlet port  704 , (c) through connector fluid path  704 P, (d) through connector outlet port  704 O, (e) through manifold port  800 A, (f) through manifold fluid inlet path  802 , (g) through manifold fluid inlet port  800 I, (h) through fluid intake path  902 A, (i) into the open end  910 B of valve stem  910 , (j) through the internal chamber  910 I, (k) through a second through hole  940 B, (1) through sealing port  840 B, (m) through second sealed channel  842 B, (n) through second manifold port  808 , (o) through second manifold fluid flow path  810 , (p) through manifold port  800 C, (q) through second fluid path connector port  712 , (r) through second connector fluid path  714 , (s) through connector port  720 , (t) through bladder fluid line  202 , and (u) into the foot support bladder  200 . If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of these parts (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     In operational state 3 shown in  FIGS.  5 C,  29 , and  30 D , at this third rotational position of the valve stem  910 , fluid moves: (a) from foot support bladder  200 , (b) through bladder fluid line  202 , (c) through connector port  720 , (d) through second connector fluid path  714 , (e) through second fluid path connector port  712 , (f) through manifold port  800 C, (g) through second manifold fluid flow path  810 , (h) through second manifold port  808 , (i) through second sealed channel  842 B, (j) through sealing port  840 B, (k) through a third through hole  940 C, (1) through the internal chamber  910 I, (m) through a fourth through hole  940 D, (n) through sealing port  840 A, (o) through first sealed channel  842 A, (p) through first manifold port  804 , (q) through first manifold fluid flow path  806 , (r) through manifold port  800 B, (s) through first fluid path connector port  706 , (t) through first connector fluid path  708 , and (u) to the external environment  150  (e.g., through the interior space  710  of connector  700 ). If necessary or desired, a one-way valve somewhere in the fluid pathway from the fluid supply (e.g., in fluid line  606 ) may prevent fluid from flowing out of the second end  910 B of valve stem  910  and into channel  902 A, through fluid inlet  800 I, and/or through fluid inlet path  802 . If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of the parts identified above (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     In operational state 4 shown in  FIGS.  5 D,  29 , and  30 E , at this fourth rotational position of the valve stem  910 , fluid moves: (a) from fluid container  400 , (b) through container fluid line  402 , (c) through connector port  722 , (d) through third connector fluid path  716 , (e) through third fluid path connector port  718 , (f) through manifold port  800 D, (g) through third manifold fluid flow path  812 , (h) through third manifold port  814 , (i) through third sealed channel  842 C, (j) through sealing port  840 C, (k) through a fifth through hole  940 E, (1) through the internal chamber  910 I, (m) through a sixth through hole  940 F, (n) through sealing port  840 A, (o) through first sealed channel  842 A, (p) through first manifold port  804 , (q) through first manifold fluid flow path  806 , (r) through manifold port  800 B, (s) through first fluid path connector port  706 , (t) through first connector fluid path  708 , and (u) to the external environment  150  (e.g., through the interior space  710  of connector  700 ). If necessary or desired, a one-way valve somewhere in the fluid pathway from the fluid supply (e.g., in fluid line  606 ) may prevent fluid from flowing out of the second end  910 B of valve stem  910  and into channel  902 A, through fluid inlet  800 I, and/or through fluid inlet path  802 . If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of the parts identified above (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     In operational state  5  shown in  FIGS.  5 E,  29 , and  30 F , at this fifth rotational position of the valve stem  910 , fluid moves: (a) from fluid container  400 , (b) through container fluid line  402 , (c) through connector port  722 , (d) through third connector fluid path  716 , (e) through third fluid path connector port  718 , (f) through manifold port  800 D, (g) through third manifold fluid flow path  812 , (h) through third manifold port  814 , (i) through third sealed channel  842 C, (j) through sealing port  840 C, (k) through a seventh through hole  940 G, (1) through the internal chamber  910 I, (m) through an eighth through hole  940 H, (n) through sealing port  840 B, (o) through second sealed channel  842 B, (p) through second manifold port  808 , (q) through second manifold fluid flow path  810 , (r) through manifold port  800 C, (s) through second fluid path connector port  712 , (t) through second connector fluid path  714 , (u) through connector port  720 , (v) through bladder fluid line  202 , and (w) into the foot support bladder  200 . If necessary or desired, a one-way valve somewhere in the fluid pathway from the fluid supply (e.g., in fluid line  606 ) may prevent fluid from flowing out of the second end  910 B of valve stem  910  and into channel  902 A, through fluid inlet  800 I, and/or through fluid inlet path  802 . If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of the parts identified above (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     In operational state 6 shown in  FIGS.  5 E,  29 , and  30 G , at this sixth rotational position of the valve stem  910 , fluid moves: (a) from the fluid supply (e.g. from external environment  150 , through connector inlet  702 I, through fluid path  702 P, through connector outlet  702 O, through fluid path  604 , through heel pump  600 H, through fluid path  602 , through forefoot pump  600 F, through fluid line  606 ), (b) through the connector inlet port  704 , (c) through connector fluid path  704 P, (d) through connector outlet port  704 O, (e) through manifold port  800 A, (f) through manifold fluid inlet path  802 , (g) through manifold fluid inlet port  800 I, (h) through fluid intake path  902 A, (i) into the open end  910 B of valve stem  910 , (j) through the internal chamber  910 I, (k) through a ninth through hole  940 I, (1) through sealing port  840 C, (m) through third sealed channel  842 C, (n) through third manifold port  814 , (o) through third manifold fluid flow path  812 , (p) through manifold port  800 D, (q) through third fluid path connector port  718 , (r) through third connector fluid path  716 , (s) through connector port  722 , (t) through container fluid line  402 , and (u) into fluid container  400 . If a specific fluid distributor  500 , foot support system, sole structure  104 , and/or article of footwear  100  does not include all of these parts (e.g., no separate connector  700 , no sealing block  840 , one or fewer foot activated pumps  600 H,  600 F, etc.), then the fluid flow through those parts would not be present in the fluid flow path described above. 
     Thus, as described above, the valve stem  910  includes a plurality of through holes  910 H (and  940 A to  940 I) defined through its perimeter wall  910 W. As evident from  FIGS.  30 B- 30 G , rotation of valve stem  910  aligns various specific holes  910 H with ports  840 A,  840 B,  840 C in the sealing connector  840  (and/or with ports  804 ,  808 ,  814  in manifold  800 , if a separate sealing connector  840  is omitted and/or if the manifold  800  itself functions as a sealing connector). The holes  910 H that align with the ports  840 A,  840 B,  840 C,  804 ,  808 ,  814  in the individual operational states of the valve stem  910  are circumferentially offset from one another so that only the one or more holes needed to make the desired fluid flow connection and pathway align with the correct ports. For operational states that rely on two (or more) through holes  910  through the perimeter wall  910 W (e.g., operational states 3, 4, and  5  above), the through holes needed to make the fluid flow connection may: (a) align along the axial length and direction of the valve stem  910 , and/or (b) extend in parallel through the perimeter wall  910 W. 
     Fluid flow rates into and/or out of the fluid transfer system  900 A may be controlled in various ways. For example, when the perimeter of a through hole  910 H in the valve stem  910  fully aligns with the port to which it is connected (e.g., sealing connector ports  840 A,  840 B,  840 C), the maximum flow rate through the hole  910 H and aligned port may be realized (e.g., depending on the pressure differential between the fluid source direction and the fluid destination direction). 
     In some instances, however, the maximum flow rate may not be desired. This may occur, for example, when a user wants to make a small pressure change in the foot support bladder  200 , when a potential overpressure situation is approaching, etc. Thus, when desired, in any operational state, valve stem  910  may be moved (e.g., rotated) to a position with respect to the corresponding connecting port (e.g.,  840 A,  840 B,  840 C,  804 ,  808 ,  814 ) so that the through hole  910 H does not completely align with the port to which it is connected.  FIGS.  31 A- 31 D  provide various examples of this type of “offset” in the axial directions of a through hole  910 H with respect to its connecting port to reduce and control the flow rate through and fluid exchange rate between the components.  FIGS.  31 A- 31 D  show examples in which two through holes  940 G,  940 H are partially aligned with a corresponding two seal ports  840 B,  840 C and two sealed channels  842 B,  842 C from operational state  5  above in  FIG.  30 F . These same types of variations, however, may be applied at the other operational states and/or when only one and/or when other through holes are to be at least partially aligned with a port. The examples of  FIGS.  31 A- 31 D  show seal connector port  840 A and sealed channel  842 A not aligned with a through hole (and thus the perimeter wall  910 W is visible through the port  840 A and channel  842 A). 
     In  FIG.  31 A , the valve stem  910  is rotationally positioned such that the central axes of through holes  940 G,  940 H are offset from the central axes of seal ports  840 C,  840 B, respectively, by 10 rotational degrees. In at least some arrangements (e.g., depending on fluid pressures, hole sizes, relative hole sizes, etc.), the offset amount results in a fluid flow rate reduction to about 41% of the full flow rate when the holes and parts are fully aligned. In  FIG.  31 B , the valve stem  910  is rotationally positioned such that the central axes of through holes  940 G,  940 H are offset from the central axes of seal ports  840 C,  840 B, respectively, by 15 rotational degrees. This example results in a fluid flow rate reduction to about 25% of the full flow rate when the holes and parts are fully aligned. In  FIG.  31 C , the valve stem  910  is rotationally positioned such that the central axes of through holes  940 G,  940 H are offset from the central axes of seal ports  840 C,  840 B, respectively, by 20 rotational degrees. This example results in a fluid flow rate reduction to about 10% of the full flow rate when the holes and parts are fully aligned. In  FIG.  31 D , the valve stem  910  is rotationally positioned such that the central axes of through holes  940 G,  940 H are offset from the central axes of seal ports  840 C,  840 B, respectively, by 25 rotational degrees. This example results in a fluid flow rate reduction to about 1% of the full flow rate when the holes and parts are fully aligned. Only a small sliver of holes  940 G,  940 H are visible in  FIG.  31 D . The reduced flow rates can be used, for example, to make minor or slow pressure adjustments, e.g., to the foot support bladder  200  and/or the fluid container  400 , to fine-tune to a desired pressure, etc. 
       FIGS.  32 A and  32 B  provide a perspective view and cross-sectional view, respectively, of the combined manifold  800  (rigid plastic) and cartridge style sealing connector  840  of one example. As shown, this example manifold  800  has: (a) four ports  800 A,  800 B,  800 C,  800 D (optionally aligned) at one surface  800 E, (b) fluid inlet port  800 I, (c) first port  804 , second port  808 , and third port  814  at another surface  800 F (e.g., the opposite surface from surface  800 E), e.g., with ports  804 ,  808 ,  814  aligned, and (d) four fluid flow paths  802 ,  806 ,  810 ,  812  through the manifold body  820  (optionally aligned and/or extending in parallel). While  FIGS.  32 A and  32 B  show end surfaces  800 E and  800 F at opposite sides of the manifold body  820  and fluid flow paths  806 ,  810 ,  812  extending straight through the manifold body  820  from surface  800 E to surface  800 F, other arrangements are possible. For example, one or more of the fluid flow paths  802 ,  806 ,  810 ,  812  may be curved and/or angled such that one or more ports  800 A,  800 B,  800 C,  800 D at one end of the fluid flow paths are not located on an opposite surface from the corresponding port  800 I,  804 ,  808 ,  814  at the other end of the fluid flow path. Any desired arrangement of ports and/or path shapes may be used. The illustrated arrangement helps maintain the manifold  800  at a relatively compact size and shape. 
     Ports  804 ,  808 ,  814  of this example (as well as surface  800 F) are located within a recess  800 R defined in the manifold body  820 . The sealing connector  840  is received in that recess  800 R and is secured by chemical bonds or opposing face seals (and optionally not just perimeter seals). The sealing connector  840  of this example includes: (a) three ports  840 A,  840 B,  840 C at one surface  840 E and (b) three sealed channels  842 A,  842 B,  842 C extending from ports  840 A,  840 B,  840 C to openings at surface  840 F (the openings in the sealing connector at surface  840 F also may be considered “ports” of the sealing connector  840 ). Surface  840 F of sealing connector  840  abuts against surface  800 F of manifold  800 , and sealed channels  842 A,  842 B,  842 C align with manifold  800  fluid flow paths  806 ,  810 ,  812 , respectively, to place the sealing connector  840  and manifold  800  in fluid communication. While  FIGS.  32 A and  32 B  show end surfaces  840 E and  840 F at opposite sides of the sealing connector  840  and sealed channels  842 A,  842 B,  842 C extending straight through the sealing connector  840  from surface  840 E to surface  840 F, other arrangements are possible. For example, one or more of the sealed channels  842 A,  842 B,  842 C may be curved and/or angled such that one or more ports  840 A,  840 B,  840 C, at one end of the fluid flow path are not located on an opposite surface from the corresponding opening at the other end of the fluid flow path. Any desired arrangement of ports, openings, and/or path shapes may be used. The illustrated arrangement helps maintain the sealing connector  840  at a relatively compact size and shape. 
     The example structures shown in  FIG.  29   -32B include sealing connector  840  having three sealed channels  842 A,  842 B,  842 C in fluid communication with three fluid flow paths  806 ,  810 ,  812  in manifold  800 . In these structures, the fluid inlet path  802  through manifold  800  does not pass through the sealing connector  840 . Rather, it directly connects with fluid intake path  902 A of housing  900  (housing  900  not shown in  FIGS.  32 A and  32 B ). As another alternative, as shown in  FIG.  32 C , the sealing connector  840  may include four ports  840 A,  840 B,  840 C,  840 D at one surface  840 E and (b) four sealed channels  842 A,  842 B,  842 C,  840 D extending from ports  840 A,  840 B,  840 C,  840 D to openings at surface  840 F (the openings in the sealing connector at surface  840 F also may be considered “ports”). The additional port  840 D and sealed channel  842 D of the example of  FIG.  32 C  may engage with fluid inlet port  800 I and flow in fluid communication with fluid inlet path  802 . The manifold  800  recess  800 R in such a structure could be increased in size and/or changed in shape to extend to include fluid inlet port  800 I and to accommodate the additional port  840 D, sealed channel  842 D, and fluid communication with fluid inlet path  802 . As another alternative, if desired, the additional port  840 D and sealed channel  842 D of the example of  FIG.  32 C  may engage with a fluid passageway in fluid communication with another component of the overall foot support system, such as another foot support bladder (if present), another fluid container (if present), etc. 
     As described above in conjunction with  FIGS.  28 A- 31 G , in some examples of this technology, the sealing connector ports  840 A,  840 B,  840 C directly engage the outer surface of the perimeter wall  910 W of the valve stem  910 . Valve stem  910  moves (e.g., rotates) to place the fluid transfer system  900 A of this example into the various operational states.  FIG.  32 C  shows features of sealing connector ports  840 A,  840 B,  840 C (and  840 D, in this example) that may assist in maintaining a sealed connection between sealing connector  840  and the valve stem  910  perimeter wall  910 W. In the illustrated examples, the outer surface of the perimeter wall  910 W of the valve stem  910  has a circular cylindrical shape and a curved perimeter (e.g., circular circumference) and cross sectional shape. To maintain better contact and seal between the sealing connector  840  and the perimeter wall  910 W, even while in relative rotation, the sealing connector ports  840 A,  840 B,  840 C (and  840 D) have an arched outer surface shape ( 840 S). This arched outer surface shape  840 S is shaped to correspond to the curvature of the perimeter wall  910 W. The arched outer surface shapes  840 S of this example have two opposed curve inflection points (e.g., local maxima)  844 A on opposite sides of the ports  840 A,  840 B,  840 C in the rotational direction of the valve stem  910  and two opposed curve inflection points (e.g., local minima)  844 B on opposite sides of the ports  840 A,  840 B,  840 C in the axial direction of the valve stem  910 . The arched outer surface shapes  840 S of this example are raised up from base surface  840 E to give the arched outer surface shapes  840 S somewhat of a “fishlips” type appearance. These shapes correspond to and maintain better contact with the curved surface of perimeter wall  910 W. If necessary or desired, the perimeter wall  910 W and/or ports  840 A,  840 B,  840 C may be treated with a lubricant (or made from materials having relatively low coefficients of friction with respect to one another, e.g., polytetrafluoroethylene containing materials, etc.) to facilitate the sliding and sealing actions of the perimeter wall  910 W with respect to  840 A,  840 B, and/or  840 C. 
       FIGS.  33 A through  37 B  illustrate aspects of this technology relating to incorporating one or more pressure sensors into the fluid flow control system and/or foot support system, e.g., to enable determination of fluid pressure within the foot support bladder  200 , the fluid container  400 , and/or other components of the system. Various types of pressure sensors may be used without departing from this technology, including, for example MPR Series pressure sensors (e.g., piezoresistive silicon pressure sensors) available from Honeywell. As some examples, pressure sensors useful in accordance with at least some aspects of this technology will have one or more of: (a) a sensing pressure range from atmospheric pressure to at least +40 psi (e.g., 14.7 to 54.7 psi); (b) a small size (e.g., 5 mm by 5 mm or less), (c) a relative accuracy or error level of less than 0.15 psi (including non-linearity, hysteresis, and non-repeatability), (d) an absolute accuracy of less than 1 psi, (e) a digital output with on-board temperature compensation, and/or (f) an update rate of 50 Hz or more. 
     In at least some examples of this technology, typically: (a) one pressure sensor  850 A is in fluid communication with third fluid flow path  812  for measuring fluid pressure in the fluid container  400  (which is in fluid communication with fluid flow path  812  via connector fluid path  716  and container fluid path  402  in at least some of the illustrated examples) and (b) another pressure sensor  850 B is in fluid communication with second fluid flow path  810  for measuring fluid pressure in the foot support bladder  200  (which is in fluid communication with fluid flow path via connector fluid path  714  and foot support fluid path  202  in at least some of the illustrated examples). Some of the figures may appear to show the pressure sensors in other labeled paths. This is done, at least in part, so that the depictions of the pressure sensors  850 A,  850 B and their ports are sufficiently separated to maintain clarity. The same types of pressure sensors, structures, and/or mountings may be used irrespective of the specific fluid channel in which the pressures are mounted. Any desired arrangement of fluid paths—coming from or going to any location—through the sealing connector  840 , manifold  800 , and/or connector  700  may be used. In addition or as an alternative to the “typical” pressure sensors  850 A,  850 B mentioned above, if desired, a pressure sensor (including one of pressure sensors  850 A,  850 B) may be placed in fluid communication with first fluid flow path  806  for measuring fluid pressure in the fluid line extending to the external environment  150  and/or in fluid inlet path  802  (e.g., from the fluid source, such as pump(s)  600 H,  600 F). 
       FIGS.  33 A- 33 F  illustrate examples of combined valve housing  902 , valve stem,  910 , sealing block  840 , and manifold  800  in which two pressure sensors  850 A and  850 B (e.g., of the types described above) are provided within separate recesses  820 R formed in the manifold body  820 . The recesses  820 R provide pressure sensor mounts in this illustrated example and extend inward from a base surface of the manifold body  820 . The pressure sensors  850 A,  850 B are sealingly engaged within the recesses  820 R of manifold body  820  with O-rings  852 . An open channel  3302  extends from the recess  820 R to the fluid channel ( 812  shown in  FIG.  33 A ) to expose the pressure sensor  850 A,  850 B to fluid pressure in the channel (similar arrangements of an open channel may be provided in other pressure sensor mount recesses  820 R). In the  FIG.  33 A  example, manifold  800  is provided as a separate component part from the valve housing  902  and is engaged with valve housing  902  (e.g., via mechanical connectors, adhesive, etc.). In the example structure shown in  FIG.  33 A , the pressure sensor mount recess(es)  820 R for receiving the pressure sensor(s)  850 A,  850 B extend into the manifold body  820  in a direction substantially perpendicular to a fluid flow direction (arrow  812 F) through the manifold fluid path (e.g.,  812 ) at the open channel 3302’s location(s). The open channel(s)  3302  may be considered an extension of the recess  820 R. 
       FIGS.  33 B- 33 F  provide various views of another example combined valve housing  902 , valve stem,  910 , sealing block  840 , and manifold  800  in which two pressure sensors  850 A and  850 B (e.g., of the types described above) are provided. In this example structure  3300 , the manifold body  820  and the valve housing  902  are formed as a one-piece construction. Sealing block  840  and valve stem  910  may be inserted into this combined manifold body  820  and the valve housing  902  structure, e.g., at the open end where encoder board or sensor  934  later may be mounted. The various parts shown in  FIGS.  33 B- 33 F  use the same reference numbers used above for the same or similar parts (and thus much of the overlapping or redundant description has been omitted). 
     One or more pressure sensors  850 A and/or  850 B may be placed at other locations in an overall system without departing from this technology.  FIGS.  34 A and  34 B  show an example structure having one or more pressure sensor mounts, e.g., tubes (two tubes  854 A,  854 B shown in  FIGS.  34 A and  34 B ) that define a recess  840 R for mounting a pressure sensor (e.g.,  850 A,  850 B), as part of a sealing connector  840 . The sealing connector  840  of this example includes: (a) a base surface  840 E including the ports  840 A,  840 B,  840 C,  840 D; (b) an outlet surface  840 F including openings (or ports)  846 A,  846 B,  846 C,  846 D for engaging ports  800 I,  804 ,  808 ,  814  of manifold  800  (manifold not shown in  FIGS.  34 A and  34 B ); and (c) sealed fluid channels  842 A,  842 B,  842 C,  842 D extending between surfaces  840 E and  840 F. Surface  840 F is provided at the free end of a block  848  of material in which the pressure sensor tube(s) (e.g.,  854 A,  854 B) is/are defined and to which the pressure sensor(s) (e.g.,  850 A,  850 B) is/are mounted. If desired, the tubular structures defining the sealed fluid channels  842 A,  842 B,  842 C,  842 D may be flexible so that the block  848  can be moved with respect to the connection to the housing  902  at surface  840 E, e.g., to ease assembly, provide tolerance, etc. The pressure sensor tube(s) (e.g.,  854 A,  854 B) may be in fluid communication with any of sealed fluid channels  842 A,  842 B,  842 C,  842 D extending between surfaces  840 E and  840 F, e.g., via open channels as described above in conjunction with  FIG.  33 A , to measure pressure in any of channels  842 A,  842 B,  842 C,  842 D and/or devices in fluid communication with them. In some examples, pressure sensors  850 A,  850 B will provide pressure readings in foot support bladder  200  and fluid container  400 . While not shown in  FIGS.  33 A- 33 F , if desired, pressure sensor mounts in a manifold body  820  may have tubular structures of the types shown in  FIGS.  34 A- 34 B  (as well as pressure sensor mounts like those shown in  FIGS.  35 A- 37 B ). 
       FIGS.  35 A and  35 B  illustrate another example in which pressure sensor(s) (e.g.,  850 A,  850 B) is/are engaged with sealing connector  840 . Different from the example of  FIGS.  34 A and  34 B , this sealing connector  840  is more like that shown in  FIG.  32 C , e.g., without flexible and/or individually apparent sealed fluid channels  842 A,  842 B,  842 C,  842 D. Rather, the sealing connector  840  of this example is more of a block  848  of material through which sealed fluid channels  842 A,  842 B,  842 C,  842 D are formed. While shown in fluid communication with sealed channels  842 B,  842 D in  FIGS.  35 A and  35 B , the pressure sensor tube(s) (e.g.,  854 A,  854 B)—and thus pressure sensor(s) (e.g.,  850 A,  850 B)—may be in fluid communication with any of sealed fluid channels  842 A,  842 B,  842 C,  842 D  extending between surfaces  840 E and  840 F, e.g., to measure pressure in any of channels  842 A,  842 B,  842 C,  842 D and/or devices in fluid communication with them. In some examples, pressure sensors  850 A,  850 B will provide pressure readings in foot support bladder  200  and fluid container  400 . 
       FIGS.  36 A and  36 B  illustrate another example in which pressure sensor(s) (e.g.,  850 A,  850 B) is/are engaged with sealing connector  840 . Different from the examples of  FIGS.  34 A- 35 B , this sealing connector  840  may be made from a somewhat more rigid material and has various connections with the valve housing  902  sealed by O-rings, gaskets, and/or other types of seals. In this illustrated example, the junction of surface  840 E with housing  902  is sealed by one or more O-rings, gaskets, and/or other types of seals  858 A, and the junctions of ports  840 A,  840 B,  840 C,  840 D with perimeter wall  910 W of valve stem  910  are sealed with O-rings, gaskets, and/or other types of seals  858 B (only one seal  858 B shown in  FIGS.  36 A- 36 B ). The sealing connector  840  of this example is a block  848  of material through which sealed fluid channels  842 A,  842 B,  842 C,  842 D are formed. While shown in fluid communication with sealed channels  842 B,  842 D in  FIG.  36 - 36 B , recess(es) (e.g.,  856 A,  856 B) defined in the block  848  of sealing connector material—and thus pressure sensor(s) (e.g.,  850 A,  850 B) received in the recess(es) (e.g.,  856 A,  856 B)— may be in fluid communication with any of sealed fluid channels  842 A,  842 B,  842 C,  842 D extending between surfaces  840 E and  840 F, e.g., to measure pressure in any of channels  842 A,  842 B,  842 C,  842 D and/or devices in fluid communication with them. In some examples, pressure sensors  850 A,  850 B will provide pressure readings in foot support bladder  200  and fluid container  400 . Pressure sensors  850 A,  850 B are engaged with sealing connector  840  within the recesses  856 A,  856 B by O-rings  852  (or gaskets or other appropriate seals). 
     Also,  FIGS.  36 A- 36 B  illustrate sealing connector  840  engaged with a manifold  800 . The manifold  800  of this example is relatively short as compared to others described above. The manifold  800  includes a base  820 A having a base surface  820 B to engage surface  840 F of the sealing connector  840  and four manifold ports  800 A,  800 B,  800 C,  800 D projecting outward from the base  820 A. These manifold ports  800 A,  800 B,  800 C,  800 D may engage a connector  700  as described above and/or may directly engage fluid tubes, e.g., coming from the fluid supply (e.g., pumps  600 H,  600 F), external environment  150 , foot support bladder  200 , and fluid container  400  (e.g., if no connector  700  is present). 
       FIGS.  37 A and  37 B  illustrate an example structure including a two part sealing connector 840—one part  840 G relatively flexible and the other part  840 H more rigid. More specifically, as shown in  FIGS.  37 A and  37 B , the flexible part  840 G of sealing connector  840  forms the direct interface with valve housing  902  and valve stem  910  perimeter wall  910 W. Seal ports  840 A,  840 B,  840 C,  840 D are provided on an extension  840 I of flexible part  840 G that extends inward from surface  840 E and into a recess  902 R defined in housing  902 . Further, this example flexible part  840 G includes tubes  854 A and  854 B for engaging pressure sensors  850 A,  850 B. This example flexible part  840 G forms the top half of a portion of the sealed channels  842 A,  842 B,  842 C,  842 D between the pressure sensors  850 A,  850 B and the valve housing  902 . The flexible part  840 G also defines the entire sealed channels  842 A,  842 B,  842 C,  842 D between the pressure sensors  850 A,  850 B and the surface  840 F of sealing connector  840  including the openings  846 A,  846 B,  846 C,  846 D for connecting to manifold  800  (or other appropriate component, e.g., if the manifold  800  and sealing connector  840  are formed as a single part). 
     The rigid part  840 H forms the bottom half of a portion of the sealed channels  842 A,  842 B,  842 C,  842 D between the pressure sensors  850 A,  850 B and the valve housing  902 . Thus, between the pressure sensors  850 A,  850 B and the valve housing  902 , the flexible part  840 G and the rigid part  840 H cooperate to define the portion of the sealed channels  842 A,  842 B,  842 C,  842 D between the pressure sensors  850 A,  850 B and the valve housing  902 . The rigid part  840 H also defines a portion of the sealed channels  842 A,  842 B,  842 C,  842 D immediately opposite the pressure sensor(s)  850 A,  850 B across the channels  842 A- 842 D. This two part sealing connector  840  may provide some flexibility, e.g., for ease of assembly, while still providing a solid overall structure. 
     As described above in conjunction with  FIGS.  28 - 30 G,  32 A,  32 B, and  33   , in some examples of this technology, the valve housing  902  may be engaged with a rigid manifold  800  component that includes recess  800 R into which a sealing connector  840  is inserted. The valve housing  902  and the manifold  800  may be joined together using any desired technique(s), such as mechanical connectors, adhesives, ultrasonic welding, laser welding, and/or other fusing techniques, etc.  FIGS.  38 A and  38 B  illustrate one example of such a connection (although similar connections may be used, if desired, to engage a sealing connector  840  with a valve housing  902 , e.g., as shown in  FIGS.  34 A- 37 B ). Each of the four corners and/or edges of the valve housing  902  and the manifold  800  of this example snap together mechanically to hold the parts together. At the interface of valve housing  902  and manifold  800 , as shown in  FIG.  38 B , flat faces  3800  are provided on each of the valve housing  902  and the manifold  800  (although grooved surfaces could be provided, if desired), e.g., around the various interfacing side surfaces. Prior to snapping the parts together, adhesive (e.g., a liquid dispensed adhesive) may be provided at the interfacing surfaces  3800  to permanently fix the valve housing  902  to the manifold  800 . Small chamfers  3802  may be included in one or both of interfacing surfaces  3800  of valve housing  902  and the manifold  800 , e.g., to provide room for any excess adhesive to be squeezed out from the interfacing surfaces  3800 . Overlapping lips  3804  also may be provided between the parts, e.g., inward from the flat faces  3800 . 
     Fluid transfer systems  900 A in accordance with at least some examples of this technology include one or more sensors for determining a position (e.g., a rotational position) of the valve stem  910  with respect to the valve housing  902  (and/or with respect to any one of more of the sealing connector  840  and/or manifold  800  (when either or both are present)).  FIG.  39    illustrates an example fluid transfer system  900 A in which a position sensor  930  is provided. Position sensing may be performed, in at least some examples of this technology, by an encoding system capable of measuring an absolute rotational position, or a relative positioning sensor with an additional index channel that denotes a specific absolute rotational position. In this illustrated example, the position sensor constitutes a magnetic encoder system  930  (e.g., an on-axis magnetic encoder system, an off-axis magnetic encoder system, etc.) including an encoder magnet  932  and a sensor  934 . This magnetic encoder system  930  is an absolute position sensor. The encoder magnet  932  is engaged with the movable (e.g., rotatable) valve stem  910  (e.g., within internal chamber  910 I at the second end  910 B) and rotates with the valve stem  910 . Changes in magnetic field strength measured at the sensor  934  indicate the position of the magnet  932  (and thus the position of the valve stem  910 ) with respect to the housing  902  or other component. The relative position of the magnet  932  (and valve stem  910 ) with respect to the housing  902  or other component also determines (and/or allows determination of) the operational state of the fluid transfer system  900 A as described above. Other types of position sensors  930  may be used without departing from at least some aspects of this technology (e.g., optical encoders, other rotational sensors, etc.). Magnetic encoder systems  930 , however, provide some advantages in that they do not require physical contact of parts and they typically will be less susceptible to failure due to adhesive, lubricant, debris, or other undesired material that may work its way into internal chamber  910 I. Optical encoders are more susceptible to failure, e.g., due to undesired material potentially masking or blocking an optical source or optical detector. Magnetic encoder systems  930  as well as other positional sensor systems are known and commercially available. 
       FIGS.  40 A- 40 C  (together with  FIG.  28    and others) provide various views of a drive system, including a motor  920  and a transmission  922  to transfer power to the first end  910 A of the valve stem  910  and to move (rotate in this example) the valve stem  910  with respect to the valve housing  902  (and/or manifold  800  and/or sealing connector  840 , etc.). A power source (e.g., from a battery) and a microcontroller, e.g., provided with the fluid distributor  500  (and not shown in  FIGS.  40 A and  40 B ), selectively drive the motor  920  to position the valve stem  910  in one of the various plurality of positions and operational states to thereby move fluid between the desired locations as described above. The motor  920  may constitute a DC coreless brushed motor (e.g., commercially available from Constar Micromotor Co., Ltd. or other commercial source). 
     The transmission  922  is mounted, at least in part, on a frame  924  (e.g., a die cast zinc frame) and may be covered by a cover plate  926  (e.g., made from metal). This specific example transmission  922 —a three stage transmission—will be described in more detail with reference to  FIGS.  40 A- 40 C . The shaft  920 S of the motor  920  engages a motor pinion  928 . The motor pinion  928  engages a large gear  928 A of a first intermediate gear cluster  928 B that additionally includes a small gear  928 C mounted on a common rotary pin  928 D (e.g., a steel pin) with large gear  928 A. The small gear  928 C of the first intermediate gear cluster  928 B engages a large outer gear  928 E of a second intermediate gear cluster  928 F. Large outer gear  928 E of second intermediate gear cluster  928 F is mounted on a common rotary pin  928 G (e.g., a steel pin) with a smaller gear  928 H of the second intermediate gear cluster  928 F. The smaller gear  928 H of the second intermediate gear cluster  928 F engages an outer geartrain  928 I of output gear  928 J. The central opening  928 K of output gear  928 J includes an inner geartrain that engages the geared end  910 G of valve stem  910 . One or more cup seals  910 S, O-rings, gaskets, or other sealing devices may be provided at the first end  910 A of valve stem  910  to prevent fluid from leaking out of the housing  902 . A nose pin  928 L secures the output gear  928 J and its associate components with the frame  922 . 
     In the example transmission system  922  shown in  FIGS.  40 A and  40 B , the axis  920 T of motor shaft  920 S extends parallel to and spaced apart from the rotational axis  910 T of the valve stem  910 .  FIGS.  41 A and  41 B  show a fluid transfer system  900 D having different arrangements of the motor  920  and valve stem  910  in which axis  920 T of motor shaft  920 S is aligned and co-linear with the rotational axis  910 T of the valve stem  910 . A planetary transmission  922 B or planetary gearbox may be used in that situation to transmit power and rotational motion from the motor  920  to the valve stem  910 . Typical planetary transmissions  922 B include a central “sun gear” (e.g., driven by motor  920  shaft  920 S) and plural “planet gears” that rotate in a cooperative manner to transmit rotational energy from the motor to a driven shaft (e.g., valve stem 910’ gear  910 G). Planetary transmissions  922 B of this type are known and commercially available. 
     The foot support systems and fluid distributors  500  described above with respect to fluid transfer system  900 A include a single foot support bladder  200  and a single fluid container  400 . If desired, however, foot support systems, fluid distributors  500 , sole structures  104 , and/or articles of footwear  100  in accordance with at least some aspects of this technology may include structures for supporting fluid pressure changes to more than one foot support bladder  200  and/or more than one fluid container  400 . When two or more foot support bladders  200  are present, fluid could be introduced to all bladders simultaneously. This could be accomplished in various ways. For example, all foot support bladders may be filled simultaneously by branching fluid line  202  into individual foot support supply lines running to corresponding individual foot support bladders. As another example, all foot support bladders in an article of footwear  100  may be filled simultaneously by fluid lines connecting the foot support bladders in series or parallel. Similarly, two or more fluid containers  400  may be filled simultaneously in the same manners, but by branching container fluid line  402  into individual lines and/or connecting the fluid containers in series or parallel. 
     If multiple foot support bladders  200  and/or fluid containers  400  are present in a single shoe  100  and it is desired to potentially provide different fluid pressures in the bladders  200  and/or containers  400 , appropriate valving or switching mechanisms may be provided, e.g., after fluid leaves connector  700  and enters foot support fluid line  202  and/or container fluid line  402 . Alternatively, if desired, a separate fluid pathway through the connector  700 , manifold  800 , and sealing connector  840  (if present) may be provided for each individual foot support bladder  200  and/or fluid container  400 ; separate through holes  910 H for the additional foot support bladder(s) and/or fluid container(s) may be provided in the valve stem  910  (e.g., axially spaced from the other through holes  910 H); and additional operational states may be provided. In other words, an additional set of ports, fluid channels, and the like as shown to move fluid into and out of foot support bladder  200  may be provided for each additional foot support bladder in the shoe  100  and/or an additional set of ports, fluid channels, and the like as shown to move fluid into and out of fluid container  400  may be provided for each additional fluid container in the shoe. The input system (e.g., on an external computing device, part of the “on-board” switching system  2200 , etc.) also may be modified to allow separate inputs and control of each additional foot support bladder and/or fluid container. 
     C. Solenoid Based Fluid Transfer System Features 
     The fluid transfer system  900 A described above utilizes a movable (e.g., rotatable) valve stem  910  that is movable to various positions to place the fluid distributor  500 , fluid flow control system, foot support system, sole structure  104 , and/or article of footwear  100  in two or more different operational states. Other types of fluid transfer systems  900 , however, may be used to place such systems and components in two or more different operational states, including any two or more of the operational states described above with respect to  FIGS.  5 A to  5 F . The following discussion relates to solenoid based fluid transfer systems  900 B in accordance with at least some aspects of this technology. 
     Various types of solenoids and/or combinations of solenoids may be used in fluid transfer systems  900 B in accordance with some aspects of this technology. Some solenoids that may be used in accordance with this technology are “latching solenoids.” Some latching solenoids, like latching solenoid  4200  shown in  FIG.  42   , include two stable states—an open state and a closed state. Such solenoids can maintain either of these stable states when no power is applied.  FIG.  42    shows solenoid  4200  in the open state in which plunger  4202  is moved rearward to allow fluid to flow through the solenoid body  4204  between one port  4206  and the other port  4208  (in either direction). See fluid flow arrow  4212 . In the closed state, spring  4210  or other biasing means forces plunger  4202  forward to close off (seal) either or both of ports  4206 ,  4208 . In that state, fluid does not flow through the solenoid body  4204 . 
     For latching solenoids, power is required to initiate movement of the plunger  4204  and change the solenoid  4200  from one state to another state. Typically, a short power pulse is applied to move the plunger  4202  of the solenoid  4200  from one position to another position. Latching solenoids also typically have a “normal state.” The “normal state” is the state the plunger  4200  will default to (e.g., due to biasing force on the plunger  4204 ) when no “latches” are activated to hold the plunger  4200  in one of the states. 
     For two-way latching solenoids, the solenoid may be “normally open” (or “NO”) in which fluid can flow through the solenoid or “normally closed (or “NC”) in which fluid cannot flow through the solenoid. Power may be applied to a normally open solenoid in a relatively short pulse to: (a) move the plunger from the open configuration to the closed configuration and (b) activate the latching mechanism to hold the solenoid in the closed position without continuous use of power. To return this solenoid back to its open configuration, power is applied to release the latch or “unlatch” the plunger in a relatively short pulse and a biasing system (e.g., spring) then returns the plunger to its open configuration. A “normally closed” solenoid works in somewhat the opposite manner. Power may be applied to a normally closed solenoid in a relatively short pulse to: (a) move the plunger from the closed configuration to the open configuration and (b) activate the latching mechanism to hold the solenoid in the open position without continuous use of power. To return this solenoid back to its closed configuration, power is applied to release the latch or “unlatch” the plunger in a relatively short pulse and a biasing system (e.g., spring) then returns the plunger to its closed configuration. In this manner, relatively low amounts of power are consumed to move the latching solenoid between its different configurations and continuous application of power for long periods of time is not needed. Because of the position of spring  4210  in  FIG.  42   , the illustrated solenoid  4200  is a “normally closed” solenoid. If spring  4210  was moved to apply its biasing force between port  4206  and the front surface  4202 S of the plunger  4202  (area A), then the solenoid would be a “normally open” solenoid. 
     Like latching solenoids, non-latching solenoids also may have one “normal” position (e.g., NO or NC) and one (or more) non-normal positions. Unlike latching solenoids, non-latching solenoids require continued application of power to maintain the valve in one of the two (or more) states. For example, a normally open (“NO”) non-latching valve requires continuous application of power to move and maintain the valve in a closed state, but it returns back to the open state when the power is shut down (e.g., under biasing force applied to the plunger). Similarly, a normally closed (“NC”) valve requires continuous application of power to move and maintain the valve in the open state, but it returns back to the closed state when the power is shut down (e.g., under biasing force applied to the plunger). Thus, in use, it can be advantageous from a power consumption and/or battery life point of view to select a normally open non-latching solenoid for applications where the valve only needs to be closed for relatively short time periods and/or to select a normally closed non-latching solenoid for applications where the valve only needs to be open for relatively short time periods. 
     As described above in conjunction with  FIGS.  4 A and  4 B  (and other figures), fluid distributors  500 , fluid flow control systems, foot support systems, sole structures  104 , and/or articles of footwear  100  in accordance with some examples of this technology include a fluid transfer system  900  for controlling the fluid flow direction and for opening/closing fluid pathways. Solenoid based fluid transfer systems  900 B (as will be described in more detail below) may be used as the fluid transfer system  900  shown in  FIG.  4 A . Thus, solenoid based fluid transfer systems  900 B in accordance with some aspects of this technology may use any of the features of the foot support bladder(s)  200 , fluid container(s)  400 , housing  502 , connector  700 , manifold  800 , sealing connector  840 , etc. described above (e.g., in conjunction with  FIGS.  1 - 41   ), except fluid transfer system(s)  900 A,  900 D is/are replaced with the fluid transfer systems  900 B described below. 
       FIG.  43    provides a schematic illustration of a solenoid based fluid transfer system  900 B that may be used as fluid transfer system  900  in the example of  FIGS.  4 A and  4 B  (and other figures). The fluid transfer system  900 B of  FIG.  43    includes three 2x2 latching solenoid valves  4300 A,  4300 B,  4300 C. While other options are possible, in this specific example, solenoid valve  4300 A is a normally open latching solenoid valve, and solenoid valves  4300 B and  4300 C are normally closed latching solenoid valves. The fluid transfer system  900 B is connected to a manifold  800  (e.g., at interface  4302 , optionally via a sealed connector  840 , if desired) that includes: (a) ports  800 A and  800 I and fluid inlet path  802  (from a fluid source, such as one or more pumps  600 H,  600 F); (b) ports  800 B and  804  and first fluid path  806  (to the external environment); (c) ports  800 C and  808  and second fluid path  810  (to and from the foot support bladder  200 ); and (d) ports  800 D and  814  and third fluid path  812  (to and from the fluid container  400 ). The solenoid valves  4300 A,  4300 B,  4300 C may be contained in a common housing  4304  that includes ports (e.g., like ports  800 A,  800 B,  800 C,  800 D, other types of connector structures, etc.) for engaging ports  800 I,  804 ,  808 ,  814  of the manifold  800 . The structure and operation of solenoid valves  4300 A,  4300 B,  4300 C and their connections with manifold  800  are described in more detail below. 
       FIG.  44 A  is an exploded view of fluid distributor  500  similar to the view of  FIG.  26 C , but the valve stem based fluid transfer system  900 A of  FIG.  26 B  is replaced with a solenoid based fluid transfer system  900 B.  FIG.  44 B  provides an assembled view of such a fluid distributor  500 . This example fluid distributor  500  includes a housing  502  in which a manifold  800  and fluid transfer system  900 B are housed. Housing  502  further defines a space  500 A for engaging a connector  700  that connects the components within housing  502  with a fluid source (e.g., the external environment, pump(s)  600 H,  600 F, a compressor, etc.), the external environment  150 , at least one foot support bladder  200 , and at least one fluid container  400 .  FIGS.  44 A and  44 B  further show potential locations of fluid transfer system  900 B within the housing  502  and a rechargeable battery  2602 , e.g., for powering the various electrical components shown and described above or below including the solenoids. Example switching components  506 A,  2200 A,  506 B,  2200 B also are shown in  FIG.  44 A  (and may have the same structures and/or functions as described for these components above). 
       FIG.  45   -47B illustrate example physical structures of solenoid based fluid transfer systems  900 B engaged with a manifold  800  and a schematic view of the fluid pathways in accordance with some aspects of this technology. As shown, these example fluid transfer systems  900 B and fluid flow control systems include: (a) a first solenoid  4300 A having a first port  4310 A and a second port  4310 B and switchable between an open configuration and a closed configuration; (b) a second solenoid  4300 B having a first port  4312 A and a second port  4312 B and switchable between an open configuration and a closed configuration; and (c) a third solenoid  4300 C having a first port  4314 A and a second port  4314 B and switchable between an open configuration and a closed configuration. 
     The first ports  4310 A,  4312 A,  4314 A of solenoids  4300 A,  4300 B,  4300 C, respectively, in this example fluid transfer system  900 B are in fluid communication with a common fluid line  4320 . Thus, common fluid line  4320  also places the first ports  4310 A,  4312 A,  4314 A of the solenoids  4300 A,  4300 B,  4300 C in fluid communication with one another (at least under some conditions). As an example, common fluid line  4320  may branch into: (a) fluid line  4310 F (going to the first port  4310 A of first solenoid  4300 A), (b) fluid line  4312 F (going to the first port  4312 A of second solenoid  4300 B), and (c) fluid line  4314 F (going to the first port  4314 A of third solenoid  4300 C). Additionally, the common fluid line  4320  also is in fluid communication with a fluid source (e.g., one or more of pump(s)  600 H,  600 F, a compressor, the external environment  150 , etc.), e.g., via one or more of manifold  800  port  800 A, fluid inlet path  802 , fluid inlet port  800 I, connector  700 , etc. 
     The second port  4310 B of first solenoid  4300 A of this example is in fluid communication with the external environment  150 , e.g., via one or more of manifold port  804 , first fluid flow path  806 , manifold port  800 B, connector  700 , etc. First solenoid  4300 A in this example is a latching solenoid having a normally open configuration. The second port  4312 B of second solenoid  4300 B of this example is in fluid communication with a foot support bladder  200 , e.g., via one or more of manifold port  808 , second fluid flow path  810 , manifold port  800 C, connector  700 , etc. Second solenoid  4300 B in this example is a latching solenoid having a normally closed configuration. The second port  4314 B of third solenoid  4300 C of this example is in fluid communication with a fluid container  400 , e.g., via one or more of manifold port  814 , third fluid flow path  812 , manifold port  800 D, connector  700 , etc. Third solenoid  4300 C in this example also is a latching solenoid having a normally closed configuration. 
     As shown in  FIG.  47 A , in this example structure, each of solenoids  4300 A,  4300 B, and  4300 C is arranged to have its first port  4310 A,  4312 A,  4313 A at one end of the solenoid and its second port  4310 B,  4312 B,  4313 B at the opposite end of the solenoid (e.g., “dual sided” solenoids). In this manner, the first ports  4310 A,  4312 A,  4313 A may be aligned at one end of the fluid transfer system  900 B and the second ports  4310 B,  4312 B,  4313 B may be aligned at the opposite end of the fluid transfer system  900 B. As shown in  FIG.  47 B , in this example structure, each of solenoids  4300 A,  4300 B, and  4300 C is arranged to have its first port  4310 A,  4312 A,  4314 A at one end of the solenoid and its second port  4310 B,  4312 B,  4314 B at a side surface of the solenoid (e.g., “single sided” solenoids). Note also the “single sided” arrangement of solenoid ports  4206  and  4208  in  FIG.  42    and the solenoid ports of  FIG.  43   . In this manner, the first ports  4310 A,  4312 A,  4314 A may be aligned at one end of the fluid transfer system  900 B and all ports are located toward this same end. These types of “single sided” arrangements can provide a compact footprint, e.g., suitable for engagement with an article of footwear  100  and/or sole structure  104 . 
       FIGS.  48 A- 48 F  provide schematic views of one example solenoid based fluid transfer system  900 B placed in the six operational states described above in conjunction with  FIGS.  5 A- 5 F .  FIG.  48 A  (along with  FIG.  5 A ) shows an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is discharged back to the external environment  150 . The fluid flow in this operational state is shown by the thick, arrowed, broken lines in  FIGS.  5 A and  48 A . This operational state may be used as a “standby” or “steady state” operational state to keep the pumped fluid moving through the fluid distributor  500  even when no pressure changes are needed to the foot support bladder  200  and/or the fluid container  400 . In this operational state, incoming fluid from the external environment  150  (e.g., air) moves, e.g., as described above with respect to  FIG.  5 A , until it goes through the manifold  800  and reaches the fluid transfer system  900 B. In this first operational state, the first solenoid  4300 A is in the open configuration, the second solenoid  4300 B is in the closed configuration, and the third solenoid  4300 C is in the closed configuration. Thus, fluid flows from the source (e.g., pumps  600 H,  600 F, a compressor, etc.), through manifold port  800 A, through common fluid line  4320 , through fluid line  4310 F, through the first port  4310 A of the first solenoid  4300 A, through the first solenoid  4300 A, through the second port  4310 B of the first solenoid  4300 A, through manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     Alternatively, in some examples of this technology, in this operational state, rather than continuously moving fluid through the fluid distributor  500  with each step when it is simply going to be discharged back into the external environment  150 , a fluid path could be provided from the pump(s)  600 H,  600 F directly to the external environment  150 . As another option, the pump(s)  600 H,  600 F could be deactivated to provide this operational state. 
       FIG.  48 B  (along with  FIG.  5 B ) shows an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is transferred to the foot support bladder  200 . The fluid flow in this operational state is shown by the thick, arrowed, broken lines in  FIGS.  5 B and  48 B . This operational state may be used to increase pressure in the foot support bladder  200 , e.g., for a firmer feel and/or to support more intense activities (such as running). In this operational state, incoming fluid from the external environment  150  (e.g., air) moves, e.g., as described above with respect to  FIGS.  5 A and  5 B , until it goes through the manifold  800  and reaches the fluid transfer system  900 B. In this second operational state, the first solenoid  4300 A is in the closed configuration, the second solenoid  4300 B is in the open configuration, and the third solenoid  4300 C is in the closed configuration. Thus, fluid flows from the source (e.g., pumps  600 H,  600 F, a compressor, etc.), through manifold port  800 A, through common fluid line  4320 , through fluid line  4312 F, through the first port  4312 A of the second solenoid  4300 B, through the second solenoid  4300 B, through the second port  4312 B of the second solenoid  4300 B, through manifold port  800 C, and to its ultimate destination (the foot support bladder  200  in this example). 
     In some instances, it may be desired to remove fluid from the foot support bladder  200  in order to decrease pressure in the foot support bladder  200  (e.g., to provide a softer feel or for less intense activities, such as walking or casual wear).  FIG.  48 C  (along with  FIG.  5 C ) shows an example of this operational state. Again, the fluid flow in this operational state is shown by the thick, arrowed, broken lines in  FIGS.  5 C and  48 C . In this third operational state, the first solenoid  4300 A is in the open configuration, the second solenoid  4300 B is in the open configuration, and the third solenoid  4300 C is in the closed configuration. Thus, fluid flows from the foot support bladder  200 , through second manifold port  800 C, through the second port  4312 B of the second solenoid  4300 B, through the second solenoid  4300 B, through the first port  4312 A of the second solenoid, through fluid line  4312 F, through the common fluid line  4320 , through fluid line  4310 F, through the first port  4310 A of the first solenoid  4300 A, through the first solenoid  4300 A, through the second port  4310 B of the first solenoid  4300 A, through manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     Another potential operational state for fluid transfer systems  900 B and foot support systems in accordance with some examples of this technology is shown in  FIG.  48 D  (along with  FIG.  5 D ). In this operational state, fluid is transferred from the fluid container  400  to the external environment, e.g., to reduce fluid pressure in the fluid container  400 . The fluid flow of this operational state is shown by the thick, arrowed, broken lines in  FIGS.  5 D and  48 D . In this fourth operational state, the first solenoid  4300 A is in the open configuration, the second solenoid  4300 B is in the closed configuration, and the third solenoid  4300 C is in the open configuration. Thus, fluid flows from the fluid container  400 , through the third manifold port  800 D, through the second port  4314 B of the third solenoid  4300 C, through the third solenoid  4300 C, through the first port  4314 A of the third solenoid  4300 C, through fluid line  4314 F, through common fluid line  4320 , through fluid line  4310 F, through the first port  4310 A of the first solenoid  4300 A, through the first solenoid  4300 A, through the second port  4310 B of the first solenoid  4300 A, through the manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     In some examples of fluid transfer systems  900 B and foot support systems according to aspects of this technology, it may be desired to use the on-board fluid container  400  to adjust (and in this example, increase) pressure in the foot support bladder  200 . An example of this operational state is shown in  FIG.  48 E  (along with  FIG.  5 E ). In this fifth operational state, the first solenoid  4300 A is in the closed configuration, the second solenoid  4300 B is in the open configuration, and the third solenoid  4300 C is in the open configuration. Thus, when the fluid container  400  pressure is higher than the foot support bladder  200  pressure, fluid flows from the fluid container  400 , through the third manifold port  800 D, through the second port  4314 B of the third solenoid  4300 C, through the third solenoid  4300 C, through the first port  4314 A of the third solenoid  4300 C, through fluid line  4314 F, through common fluid line  4320 , through fluid line  4312 F, through the first port  4312 A of the second solenoid  4300 B, through the second solenoid  4300 B, through the second port  4312 B of the second solenoid  4300 B, through manifold port  800 C, and to its ultimate destination (the foot support bladder  200  in this example). 
       FIG.  48 F  (along with  FIG.  5 F ) shows an example operational state for adding fluid to the fluid container  400  (e.g., to increase fluid volume and/or pressure in the fluid container  400 ). In this sixth operational state, the first solenoid  4300 A is in the closed configuration, the second solenoid  4300 B is in the closed configuration, and the third solenoid  4300 C is in the open configuration. Thus, fluid flows from the source (e.g., pumps  600 H,  600 F, a compressor, etc.), through manifold port  800 A, through common fluid line  4320 , through fluid line  4314 F, through the first port  4314 A of the third solenoid  4300 C, through the third solenoid  4300 C, through the second port  4314 B of the third solenoid  4300 C, through manifold port  800 D, and to its ultimate destination (the fluid container  400  in this example). 
     As mentioned above, fluid distributors  500 , fluid flow control systems, foot support systems, sole structures  104 , and/or articles of footwear  100  in accordance with some examples of this technology need not provide all six of the operational states described above. Rather, more operational states, less operational states, and/or different operational states may be available in some examples of this technology.  FIGS.  49 A- 49 D  illustrate an example solenoid based fluid transfer system  900 C having four operational states when one foot support bladder  200  and one fluid container  400  are present. 
     This example fluid transfer system  900 C includes two solenoids: (a) a first solenoid  4900 A including a first port  4910 A, a second port  4910 B, and a third port  4910 C; and (b) a second solenoid  4900 B including a first  4912 A port and a second port  4912 B. The first ports  4910 A and  4912 A of solenoids  4900 A,  4900 B, respectively, in this example fluid transfer system  900 C are in fluid communication with a common fluid line  4920 . Thus, common fluid line  4920  also places the first ports  4910 A,  4912 A of the solenoids  4900 A,  4900 B in fluid communication with one another (at least under some conditions). As an example, common fluid line  4920  may branch into: (a) fluid line  4910 F (going to the first port  4910 A of first solenoid  4900 A) and (b) fluid line  4912 F (going to the first port  4912 A of second solenoid  4900 B). Additionally, the common fluid line  4920  also is in fluid communication with a fluid source (e.g., one or more of pump(s)  600 H,  600 F, a compressor, the external environment  150 , etc.), e.g., via one or more of manifold  800  port  800 A, fluid inlet path  802 , fluid inlet port  800 I, connector  700 , etc. In this example, the first solenoid  4900 A may be a latching three port, two state solenoid (a 3/2 solenoid) and the second solenoid  4900 B may be a normally closed non-latching solenoid (a 2/2 solenoid), although other specific types of solenoids may be used, if desired. The fluid transfer system  900 C may engage with a manifold  800 , e.g., of the various types described above (e.g., a four port and four fluid path manifold of the types described above). 
     In this illustrated example (and as will be described in more detail below), the first solenoid  4900 A is independently switchable to: (a) a first configuration in which fluid flows through the first solenoid  4900 A between the first port  4910 A and the second port  4910 B and (b) a second configuration in which fluid flows through the first solenoid  4900 A between the first port  4910 A and the third port  4910 C. Thus, in this example, first port  4910 A and first solenoid  4900 A always remain open and the plunger  4910 P moves between: (a) one position in which second port  4910 B is open and third port  4910 C is closed and (b) another position in which second port  4910 B is closed and third port  4910 C is open. The first solenoid  4900 A in the illustrated example is biased to “normally” be in the first configuration (with the biasing system closing third port  4910 C). The second solenoid  4900 B of this example is independently switchable between an open configuration (in which fluid flows through solenoid  4900 B between the first port  4912 A and the second port  4912 B) and a closed configuration (in which fluid does not flow through solenoid  4900 B). In this fluid transfer system  900 C, simultaneous selective placement of: (a) the first solenoid  4900 A in one of the first configuration or the second configuration and (b) the second solenoid  4900 B in one of the open configuration or the closed configuration selectively places this fluid transfer system  900 C in a plurality of (e.g., two or more) operational states. Examples of these operational states are described in more detail below. 
       FIGS.  49 A- 49 D  provide schematic views of the solenoid based fluid transfer system  900 C placed in four operational states.  FIG.  49 A  (along with  FIG.  5 A ) shows an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is discharged back to the external environment  150 . The fluid flow in this operational state is shown by the thick, arrowed, broken lines in  FIGS.  5 A and  49 A . This operational state may be used as a “standby” or “steady state” operational state to keep the pumped fluid moving through the fluid distributor  500  even when no pressure changes are needed to the foot support bladder  200  and/or the fluid container  400 . In this operational state, incoming fluid from the external environment  150  (e.g., air) moves, e.g., as described above with respect to  FIG.  5 A , until it goes through the manifold  800  and reaches the fluid transfer system  900 C. In this first operational state, the first solenoid  4900 A is in the first configuration and the second solenoid  4900 B is in the closed configuration. Thus, fluid flows from the source (e.g., pumps  600 H,  600 F, a compressor, etc.), through manifold port  800 A, through common fluid line  4920 , through fluid line  4910 F, through the first port  4910 A of the first solenoid  4900 A, through the first solenoid  4900 A, through second port  4910 B of the first solenoid  4900 A, through manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     Alternatively, in some examples of this technology, in this operational state, rather than continuously moving fluid through the fluid distributor  500  with each step when it is simply going to be discharged back into the external environment  150 , a fluid path could be provided from the pump(s)  600 H,  600 F directly to the external environment  150 . As another option, pump(s)  600 H,  600 F could be deactivated to accomplish this operational state. 
       FIG.  49 B  (along with  FIG.  5 F ) shows an example operational state for adding fluid to the fluid container  400  (e.g., to increase fluid volume and/or pressure in the fluid container  400 ). In this second operational state, the first solenoid  4900 A is in the second configuration and the second solenoid  4900 B is in the closed configuration. Thus, fluid flows from the source (e.g., pumps  600 H,  600 F, a compressor, etc.), through manifold port  800 A, through common fluid line  4920 , through fluid line  4910 F, through the first port  4910 A of the first solenoid  4900 A, through the first solenoid  4900 A, through third port  4910 C of the first solenoid  4900 A, through manifold port  800 D, and to its ultimate destination (the fluid container  400  in this example). 
     In this example fluid transfer system  900 C, the on-board fluid container  400  is used to adjust (and in this example, increase) fluid pressure in the foot support bladder  200 . An example of this operational state is shown in  FIG.  49 C  (along with  FIG.  5 E ). In this third operational state, first solenoid  4900 A is in the second configuration and the second solenoid  4900 B is in the open configuration. Thus, when the fluid container  400  pressure is higher than the foot support bladder  200  pressure, fluid flows from the fluid container  400 , through the third manifold port  800 D, through the third port  4910 C of the first solenoid  4900 A, through the first solenoid  4900 A, through the first port  4910 A of the first solenoid  4900 A, through fluid line  4910 F, through common fluid line  4920 , through fluid line  4912 F, through the first port  4912 A of the second solenoid  4900 B, through the second solenoid  4900 B, through second port  4912 B of the second solenoid  4900 B, through manifold port  800 C, and to its ultimate destination (the foot support bladder  200  in this example). 
     In some instances, it may be desired to remove fluid from the foot support bladder  200  in order to decrease pressure in the foot support bladder  200  (e.g., to provide a softer feel or for less intense activities, such as walking or casual wear).  FIG.  49 D  (along with  FIG.  5 C ) shows an example of this operational state. The fluid flow in this operational state is shown by the thick, arrowed, broken lines. In this fourth operational state, the first solenoid  4900 A is in the first configuration and the second solenoid  4900 B is in the open configuration. Thus, fluid flows from the foot support bladder  200 , through second manifold port  800 C, through the second port  4912 B of the second solenoid  4900 B, through the second solenoid  4900 B, through the first port  4912 B of the second solenoid  4900 B, through fluid line  4912 F, through the common fluid line  4920 , through fluid line  4910 F, through the first port  4910 A of the first solenoid  4900 A, through the first solenoid  4900 A, through the second port  4910 B of the first solenoid  4900 A, through manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     Thus, as compared to fluid transfer system  900 B, fluid transfer system  900 C includes up to four operational states rather than the six operational states described above for fluid transfer system  900 B. Specifically, fluid transfer system  900 C of  FIGS.  49 A- 49 D  does not have an operational state in which fluid moves into the fluid distributor  500  from the external environment  150  and is transferred directly into the foot support bladder  200  (the states shown in  FIGS.  5 B and  48 B ). Rather, in the fluid transfer system  900 C of  FIGS.  49 A- 49 D , fluid pressure is increased in the foot support bladder  200  only by fluid transfer from the fluid container  400  to the foot support bladder  200  (as shown by the operational state of  FIG.  49 C ). Further, as compared to fluid transfer system  900 B, fluid transfer system  900 C does not have an operational state in which fluid moves from the fluid container  400  to the external environment  150  (the states shown in  FIGS.  5 D and  48 D ). If necessary or desired, fluid container  400  may include a check valve that opens to the external environment to prevent over-pressurization of the fluid container  400  (rather than having excess fluid from container  400  passing through fluid transfer system  900 C to reduce pressure in the fluid container  400 ). Additionally or alternatively, if fluid pressure from the fluid source (e.g., fluid pressure generated by one or more foot activated pumps  600 H,  600 F) is insufficient or below the fluid pressure in open fluid pathways to the fluid container  400 , fluid will not transfer from the source to the fluid container  400 . Still additionally or alternatively, other pressure relief valves and/or fluid pathways may be provided at one or more locations in the overall fluid transfer system  900 C, fluid distributor  500 , fluid flow control system, foot support system, sole structure  104 , and/or article of footwear  100  to prevent over-pressurization of any part of the systems (e.g., to relieve pressure from fluid discharged by pump(s)  600 H,  600 F if there is no other place for the fluid to go). 
     Fluid transfer system  900 C has some advantages, however, in that it uses only two solenoids as compared to three used in fluid transfer system  900 B. Thus, fluid transfer system  900 C may be somewhat lighter, smaller, less expensive, and/or more energy efficient (e.g., consume less battery power) as compared to fluid transfer system  900 B. 
     Fluid transfer systems  900 B and  900 C described above include a single foot support bladder  200  and a single fluid container  400 . If desired, however, fluid transfer systems, foot support systems, fluid distributors  500 , sole structures  104 , and/or articles of footwear  100  in accordance with at least some aspects of this technology may include structure for supporting fluid pressure changes to more than one foot support bladder  200  and/or more than one fluid container  400 . When two or more foot support bladders  200  are present, fluid could be introduced to all bladders simultaneously. This could be accomplished in various ways. For example, all foot support bladders may be filled simultaneously by branching fluid line  202  into individual foot support supply lines running to corresponding individual foot support bladders. As another example, all foot support bladders in an article of footwear  100  may be filled simultaneously by fluid lines connecting the foot support bladders in series or parallel. Similarly, two or more fluid containers  400  may be filled simultaneously in the same manners, but by branching container fluid line  402  into individual lines and/or connecting the fluid containers in series or parallel. 
     If multiple foot support bladders  200  and/or fluid containers  400  are present in a single shoe  100  and it is desired to potentially provide different fluid pressures in the bladders  200  and/or containers  400 , appropriate valving or switching mechanisms may be provided, e.g., after fluid leaves connector  700  and enters foot support fluid line  202  and/or container fluid line  402 . Alternatively, if desired, a separate fluid pathway through the connector  700 , manifold  800 , and sealing connector  840  (if present) may be provided for each individual foot support bladder  200  and/or fluid container  400 ; separate solenoids may be provided for each additional foot support bladder  200  and/or fluid container  400 ; and additional operational states may be provided. In other words, an additional set of ports, fluid channels, solenoids, and the like as shown to move fluid into and out of foot support bladder  200  may be provided for each additional foot support bladder and/or an additional set of ports, fluid channels, solenoids, and the like as shown to move fluid into and out of fluid container  400  may be provided for each additional fluid container in the shoe. The input system (e.g., on an external computing device, part of the “on-board” switching system  2200 , etc.) also may be modified to allow separate inputs and control of each additional foot support bladder and/or fluid container. 
       FIGS.  49 A- 49 D  schematically illustrate (as “optional”) a second foot support bladder  250  in fluid transfer system  900 C. Thus, in this fluid transfer system  900 C, a third solenoid  4900 C is provided to transfer fluid into and out of second foot support bladder  250 . This third solenoid  4900 C includes a first port  4914 A and a second port  4914 B, and it may be structured as a normally closed non-latching solenoid, e.g., a 2/2 solenoid. The first port  4914 A of third solenoid  4900 C may have a fluid line  4914 F in fluid communication with the common fluid line  4920 . The second port  4914 B of the third solenoid  4900 C is in fluid communication with the second foot support bladder  250  in any desired manner. Specifically, the fluid pathway from second port  4914 B to foot support bladder  250  may have a separate set of ports and fluid paths through manifold  800 , sealing connector  840  (if present), connector  700  (if present), etc., that generally correspond in structure and/or function to the fluid pathway between second port  4912 B of second solenoid  4900 B and foot support bladder  200 . 
     The fluid transfer system  900 C of  FIGS.  49 A- 49 D  may be placed in all the operational states shown in  FIGS.  49 A- 49 D  by placing the first solenoid  4900 A and second solenoid  4900 B in the configurations shown in  FIGS.  49 A- 49 D  and maintaining third solenoid  4900 C in the closed configuration. But, this example fluid transfer system  900 C may include two additional operational states to accommodate: (a) increases in fluid pressure in the second foot support bladder  250  and (b) decreases in fluid pressure in the second foot support bladder  250 . A fifth operational state used to increase fluid pressure in the second foot support bladder  250  utilizes the first solenoid  4900 A in the second configuration, the second solenoid  4900 B in the closed configuration, and the third solenoid  4900 C in the open configuration. Thus, in a manner similar to the configuration shown in  FIG.  49 C , fluid moves from fluid container  400 , through the third manifold port  800 D, through the third port  4910 C of the first solenoid  4900 A, through the first solenoid  4900 A, through the first port  4910 A of the first solenoid  4900 A, through fluid line  4910 F, through common fluid line  4920 , through fluid line  4914 F, through the first port  4914 A of the third solenoid  4900 C, through the third solenoid  4900 C, through second port  4914 B of the third solenoid  4900 B, and from there to its ultimate destination (the foot support bladder  250  in this example). 
     Similarly, a sixth operational state used to decrease fluid pressure in the second foot support bladder  250  utilizes the first solenoid  4900 A in the first configuration, the second solenoid  4900 B in the closed configuration, and the third solenoid  4900 C in the open configuration. Thus, in a manner similar to the configuration shown in  FIG.  49 D , fluid moves from the foot support bladder  250  (through whatever fluid pathways are provided) through the second port  4914 B of the third solenoid  4900 C, through the third solenoid  4900 C, through the first port  4914 A of the third solenoid  4900 C, through fluid line  4914 F, through the common fluid line  4920 , through fluid line  4910 F, through the first port  4910 A of the first solenoid  4900 A, through the first solenoid  4900 A, through the second port  4910 B of the first solenoid  4900 A, through manifold port  800 B, and to its ultimate destination (the external environment  150  in this example). 
     An additional solenoid (e.g., 2/2 non-latching solenoid) and appropriate structures and operational states may be provided for any additional foot support bladders beyond bladders  200  and  250  discussed above. 
     As described herein, aspects of this technology relate to controlling and changing pressure in various footwear components, such as one or more foot support bladders  200  and/or one or more fluid reservoirs  400  (which also may be fluid filled bladders). In the various example structures described above, however, the pressure sensors (e.g.,  850 A,  850 B) are not located directly inside or directly engaged with the corresponding foot support bladder  200  and/or fluid container  400 . Incorporating pressure sensor(s)  850 A,  850 B directly into or with a foot support bladder  200  and/or fluid container  400  of the types described herein may be practically difficult, e.g., due to the pliable bladder structures, due to their locations within the footwear, due to footwear assembly difficulties, etc. Thus, as described above, systems and methods in accordance with at least some aspects of this technology provide pressure sensor(s)  850 A,  850 B at locations to measure pressure in fluid lines within manifold  800  or within sealing connector  840 . These fluid lines, in turn, are in fluid communication with foot support bladder  200  and/or fluid container  400 . In this manner, the pressure sensor(s)  850 A,  850 B may be provided with external fluid distributor  500  (as described above) and may be more easily and conveniently incorporated into the overall footwear  100  structure as the fluid distributor  500  is connected with the shoe  100 . 
     When no fluid is flowing through the relevant fluid lines equipped with sensors  850 A,  850 B, those sensors  850 A,  850 B generally will accurately measure pressure in the foot support bladder  200  and/or fluid container  400  (because the sensors  850 A,  850 B are mounted at fluid lines in open fluid communication with the foot support bladder  200  and/or fluid container  400 ). But, because the pressure sensor(s)  850 A,  850 B are not directly included with the foot support bladder  200  and/or fluid container  400 , the pressure measurements made at pressure sensor(s)  850 A,  850 B within the manifold  800  or sealing connector  840  when fluid is flowing through the relevant fluid lines may not correspond to the actual pressure present within the foot support bladder  200  and/or fluid container  400 . For example, there may be significant flow restriction on fluid flowing through the manifold  800  and/or sealing connector  840  because the fluid flows through relatively small sized (e.g., small cross sectional area and/or diameter) fluid lines within the manifold  800   and/or sealing connector  840 . This flow resistance at the pressure sensor  850 A,  850 B locations causes corresponding differences in the pressure readings taken at the sensors  850 A,  850 B (and at the manifold  800  and/or sealing connector  840 ) as compared to the actual pressures at foot support bladder  200  and/or fluid container  400 . This “difference” in sensed pressure v. actual pressure may be referred to as “offset.” During fluid flow, this flow resistance offset also may be affected by flow rate past the pressure sensors  850 A,  850 B (i.e., flow rate dependent offset). Flow resistance offset also may be more pronounced shortly after fluid flow starts, stops, and/or changes rate significantly. 
     For these reasons, systems and methods in accordance with at least some aspects of this technology may determine an “adjusted” pressure (e.g., adjusted for offset) based on the pressure readings taken at the pressure sensor(s) (e.g.,  850 A,  850 B) within the manifold  800  and/or sealing connector  840 . These adjusted pressure(s) then may be used as input (e.g., input data to the microprocessor of an on-board fluid distributor  500 , input data to an external computing device controlling pressure change operations, etc.) for determining when to start and stop fluid flow (e.g., when to rotate valve stem  910  and/or when to change the configuration of one or more solenoids (e.g.,  4300 A- 4300 C,  4900 A- 4900 C) when adjusting pressure in the foot support bladder  200  and/or the fluid container  400 ). Use of adjusted pressure(s) for controlling pressure changes may allow the fluid flow control system to better arrive at a target pressure in response to pressure change input. For example, use of the adjusted pressure, as opposed to directly using the sensor  850 A,  850 B measured pressures, may allow the systems and/or methods to arrive at the target pressure more directly and/or with less pressure change “overshoot” (i.e., inflating too much) or “undershoot” (deflating too much) in the foot support bladder  200  and/or fluid container  400  (as compared to using the actual pressure sensor  850 A,  850 B readings). Additionally or alternatively, this may allow the systems and/or methods to arrive at the target pressure with less cycles of “starting” and “stopping” the fluid flow to arrive at the final target pressure (and especially with fewer short bursts of starts to fine tune and adjust pressure to the final target pressure). 
     In some examples of this aspect of the present technology, adjusted pressures due to flow rate dependent offset may be determined using a state observer model. A state observer model uses a system that provides an estimate of the internal state of a given real system (in this example, the actual pressure in foot support bladder  200  and/or fluid container  400 , P ACTUAL ) from measurements of a real system (in this example, pressure measurements at pressure sensors  850 A,  850 B (P 850A,   850B ) at manifold  800  and/or sealing connector  840 ).  FIGS.  50 A and  50 B  provide figures helping explain one potential state observer model.  FIG.  50 A  shows an electrical equivalent model  5000  of a pneumatic pressure control system of the types described herein in which the actual system includes one foot support bladder  200  (“cushion”) and one fluid container  400  (“tank”). In this model, the fluid container  400  and the foot support bladder  200  are modeled as capacitors and store pressure. Fluid flow through the various parts of the system is modeled as resistors (e.g., fluid flow between the fluid container  400  and the fluid transfer system  900  is shown as resistor  5020 , fluid flow through the fluid transfer system  900  is shown as resistor  5022 , and fluid flow between the foot support bladder  200  and the fluid transfer system  900  is shown as resistor  5024 ). 
       FIG.  50 B  illustrates how the state observer model  5000  of  FIG.  50 A  corresponds to the actual pressure measurements in sensors  850 A,  850 B (and other related information). Line  5002  represents desired target pressure in the foot support bladder  200  and shows a desired pressure change from about 18 psi to about 27 psi shortly before time 358.5. Lines  5004  and  5006  represent operation of solenoid valves for fluid container  400  and the foot support bladder  200 , respectively. These lines  5004 ,  5006  show that both solenoid valves change configuration when the desired pressure change is triggered (shortly before time 358.5). The valve configuration changes configure the solenoids to allow fluid to transfer from the fluid container  400  to the foot support bladder  200  (thereby increasing pressure in the foot support bladder  200  and decreasing pressure in the fluid container  400 ). Curve  5008  shows the actual pressure measurements taken by sensor  850 A in the manifold/sealing connector fluid line in fluid communication with the fluid container  400 , and curve  5010  shows the actual pressure measurements taken by sensor  850 B in the manifold/sealing connector fluid line in fluid communication with the foot support bladder  200 . As evident from curves  5008 ,  5010 , the actual sensor  850 A,  850 B measurements jump significantly when flow starts and stops due to flow resistance offset. This flow resistance offset typically becomes even more pronounced as the fluid line cross sectional area decreases. 
     Curves  5012  and  5014 , on the other hand, show the pressure values predicted/calculated by the model  5000  of  FIG.  50 A . As shown, these curves  5012 ,  5014  lack the substantial “jumps” and thus better correspond to the actual fluid pressures within the fluid container  400  and/or foot support bladder  200 . From the actual measured pressure readings at pressure sensors  850 A and/or  850 B, state observer pressure values may be calculated using the model  5000 . For example, based on the pressure sensor measurements  850 A,  850 B (which correlate to voltage measured by the sensors  850 A,  850 B), and in view of the known values assigned to the various resistors  5020 ,  5022 ,  5024  and capacitances (Tank and Cushion) in model  5000 , the voltages at fluid container model location  5026  and foot support bladder model location  5028  can be calculated. These calculated voltages correspond to the pressure calculated state observer pressure values. 
     Then these calculated state observer pressure values may be used as inputs corresponding to pressure in the foot support bladder  200  and/or fluid container  400 . The use of the calculated state observer pressure values as pressure input and data allows systems and methods in accordance with some examples of this technology to better control pressure changes, arrive at target pressures more directly and/or with less pressure change “overshoot” (i.e., inflating too much) or “undershoot” (deflating too much), and/or with less cycles of “starting” and “stopping” the fluid flow to arrive at the target pressure (e.g., due to the lack of “jumps”). 
     Other ways of using actual pressure readings from pressure sensors  850 A,  850 B to determine an adjusted pressure value (and estimate actual pressure in foot support bladder  200  and/or fluid container  400 ) may be used. As one example, a laboratory physical model of the overall foot support system may be formed including the same interconnected foot support bladder  200 , fluid lines  400 , fluid distributor  500  components, but the model could be made to additionally include pressure sensors with the foot support bladder  200  and fluid container  400  to measure the actual pressure in those components. Then, using this physical model, pressure measurements may be taken: (a) at the pressure sensor(s)  850 A,  850 B located at manifold  800  and/or sealing connector  840  (P 850A,   850B ), and (b) at the additional pressure sensor(s) included with the foot support bladder  200  and/or fluid container  400  as part of the physical model (P ACTUAL ) under various operating conditions (e.g., using different flow rates, using different starting pressures, using different pressure change amounts, etc.). By comparing the actual pressure measurements of part (a) with those of part (b), the differences in the actual measured pressures can be used to develop correction factors to be used in systems and methods where actual pressure measurements are available only at manifold  800  and/or sealing connector  840  (i.e., in actual shoes in use where no additional pressure sensor(s) is (are) included directly with the foot support bladder  200  and/or fluid container  400 ). The correction factor may take on the form of a look-up table, a mathematical formula or equation for convertingP 850A,   850B  to P ACTUAL , a “best fit” curve, etc., and may be applied by the microprocessor to the actual pressure readings P 850A,   850B . Applying an appropriate correction factor for the conditions to the pressure sensor measurements at manifold  800  and/or sealing connector  840  (P 850A,   850B ) provides an adjusted pressure value that may be used as input for controlling pressure changes, e.g., as described above. 
       FIGS.  51 A- 51 F  schematically illustrate movement of fluid in various operational states or modes of other example fluid distribution systems, foot support systems  5100 , and/or articles of footwear in accordance with some aspects of this technology. These example fluid distribution systems and/or foot support systems  5100  may be used in articles of footwear and/or sole structures, e.g., of any of the types described above. Similar to other examples described above, this example foot support system  5100  includes: (a) two independent foot support bladders  200 A,  200 B (e.g., a heel support bladder and a forefoot support bladder; a medial side bladder and a lateral side bladder; etc.), (b) a pump (e.g., one or more foot-activated pumps  600 F,  600 H, a powered pump, a compressor, etc.), and (c) a fluid tank  400  (or reservoir) (e.g., one or more fluid-filled bladders included with the footwear upper  102  and/or sole structure  104 ). The foot support bladder(s)  200 A,  200 B may be incorporated into an article of footwear and/or sole structure (e.g., part of a midsole component, embedded in or engaged with a foam component, etc.), e.g., in any of the manners described above. Additionally or alternatively, the pump(s) (e.g.,  600 H,  600 F) may be incorporated into or engaged with an article of footwear and/or sole structure, e.g., in any of the manners described above. Still additionally or alternatively, the fluid tank  400  (e.g., a reservoir, a fluid-filled bladder, etc.) may be incorporated into an article of footwear, a footwear upper, and/or a sole structure (e.g., part of a midsole component, embedded in a foam midsole component, part of a footwear upper, engaged with a footwear upper component, etc.), e.g., in any of the manners described above. Information relating to potential different operational states provided below will assist in understanding the component parts of the fluid distributor  720 , foot support systems, and articles of footwear according to aspects of this present technology. 
     The example foot support system  5100  of  FIGS.  51 A- 51 F  includes two solenoids: (a) a first solenoid  5100 A including a first port  5110 A, a second port  5110 B, and a third port  5110 C; and (b) a second solenoid  5100 B including a first port  5112 A, a second port  5112 B, and a third port  5112 C. The first solenoid  5100 A in this illustrated example may constitute a 3/2 solenoid (e.g., a latching 3/2 solenoid valve (a three port, two state solenoid)), and the second solenoid  5100 B also may constitute a 3/2 solenoid (e.g., a three port, two state solenoid, latching or non-latching). Another valve  5100 C is provided in this example, and this valve  5100 C may constitute a 2/2 solenoid valve (e.g., a normally closed (“NC”) solenoid (e.g., latching or non-latching)). Valve  5100 C includes a first port  5114 A and a second port  5114 B. The first ports  5110 A and  5114 A of solenoid  5100 A and valve  5100 C, respectively, are in fluid communication with each other via fluid distribution line  5120 . Additionally, fluid distribution line  5120  also is in fluid communication with fluid line  606  from a fluid source (e.g., pump  600 H,  600 F, a compressor, the external/ambient environment  150 , through a filtered fluid supply inlet  732 , etc.). Fluid line  606  further includes a one-way or check valve  606 V to prevent fluid from flowing back into the fluid supply (e.g., pump  600 H,  600 F) through fluid line  606 . 
     In this illustrated example (and as will be described in more detail below), the first solenoid  5100 A is independently switchable to: (a) a first configuration in which fluid flows through the first solenoid  5100 A between the first port  5110 A and the second port  5   110 B (in either direction) and (b) a second configuration in which fluid flows through the first solenoid  5100 A between the first port  5110 A and the third port  5110 C. Thus, in this example, first port  5110 A and first solenoid  5100 A always remain open and the plunger  5110 P moves between: (a) one position in which second port  5110 B is open and third port  5110 C is closed (see  FIGS.  51 B- 51 D ) and (b) another position in which second port  5110 B is closed and third port  5110 C is open (see  FIGS.  51 A,  51 E,  51 F ). The first solenoid  5100 A in the illustrated example may be biased to “normally” be in the second configuration (with the biasing system (e.g., a spring applying force to plunger  5110 P) closing second port S110B). The second port  5110 B in this example is connected to the fluid tank  400  via fluid line  5116 A, and the third port  5110 C in this example is open to (e.g., connected via a fluid line  5116 B) to the ambient environment  150 . 
     The second solenoid  5100 B of this illustrated example is independently switchable to: (a) a first configuration in which fluid flows through the second solenoid  5100 B between the first port  5112 A and the second port  5112 B (in either direction) and (b) a second configuration in which fluid flows through the second solenoid  5100 B between the first port  5112 A and the third port  5112 C (in either direction). Thus, in this example, first port  5112 A and second solenoid  5100 B always remain open and the plunger  5112 P moves between: (a) one position in which second port  5112 B is open and third port  5112 C is closed (see  FIGS.  51 A- 51 C,  51 E ) and (b) another position in which second port  5112 B is closed and third port  5112 C is open (see  FIGS.  51 D,  51 F ). The second solenoid  5100 B in the illustrated example is biased to “normally” be in the first configuration (with the biasing system (e.g., a spring applying force to plunger  5112 P) closing third port  5112 C). The second port  5112 B in this example is connected to the first foot support bladder  200 A via fluid line  5118 A, and the third port  5112 C in this example is connected to the second foot support bladder  200 B via fluid line  5118 B. Alternatively, if desired, second solenoid  5100 B could be “normally” in the second configuration. 
     As noted above, valve  5100 C of this example may constitute a solenoid valve (e.g., a two port, two state solenoid, normally closed, latching or non-latching). Valve  5100 C is independently switchable to: (a) an open configuration in which fluid flows through the valve  5100 C (between first port  5114 A and second port  5114 B in either direction—see  FIGS.  51 C- 51 F ) and (b) a closed configuration in which fluid does not flow through the valve  5100 C (see  FIGS.  51 A,  51 B ). Plunger  5114 P moves in this example to open or close first port  5114 A to change between its open and closed configurations, although the plunger  5114 P could open and/or close second port  5114 B in other examples of this technology. 
     In this example foot support system  5100 , simultaneous selective placement of: (a) the first solenoid  5100 A in one of its first configuration or second configuration, (b) the second solenoid  5100 B in one of its first configuration or second configuration, and (c) the third solenoid  5100 C in one of its open configuration or closed configuration selectively places this foot support system  5100  in a plurality of (e.g., two or more) operational states. Examples of these operational states are described in more detail below. 
       FIGS.  51 A- 51 F  provide schematic views of this example solenoid based foot support system  5100  placed in six operational states.  FIG.  51 A  shows an operational state in which fluid moves from the external environment  150  (e.g., through filtered fluid inlet  732 ) and is discharged back to the external environment  150 . The fluid flow in this operational state (as well as the fluid flow in the operational states of  FIGS.  51 B- 51 F ) is shown by the thick, arrowed, broken lines in  FIG.  51 A . This operational state may be used as a “standby” or “steady state” operational state to keep the pumped fluid (e.g., from a foot-activated pump  600 H,  600 F) moving through the foot support system  5100  even when no pressure changes are needed to the foot support bladders  200 A,  200 B and/or the fluid container  400 . In this operational state, the first solenoid  5100 A is in the second configuration and the valve  5100 C is in the closed configuration. Because valve  5100 C is closed, second solenoid  5100 B can be either in its first configuration or second configuration. In this operational state, incoming fluid from the external environment  150  (e.g., air) moves from the external environment  150  (e.g., via fluid supply inlet  732  of the fluid distributor  720 ), through fluid line  604 , through pump(s)  600 H,  600 F, through fluid line  606 , through fluid distribution line  5120 , through the first port  5110 A of the first solenoid  5100 A, through the first solenoid  5100 A, through the third port  5110 C of the first solenoid  5100 A, into the fluid release fluid line  5116 B, and to its ultimate destination (back to the external environment  150  in this example). 
     Alternatively, in some examples of this technology, in this operational state (e.g., a “standby” state), rather than continuously moving fluid through the foot support system  5100  with each step when it is simply going to be discharged back into the external environment  150 , a fluid path could be provided from the pump(s)  600 H,  600 F directly to the external environment  150 . As another option, pump(s)  600 H,  600 F could be deactivated to accomplish this operational state. 
       FIG.  51 B  shows an example operational state for adding fluid to the fluid container  400  (e.g., to increase fluid mass, volume, and/or pressure in the fluid container  400 ). In this second operational state, the first solenoid  5100 A is in the first configuration and the valve  5100 C is in the closed configuration. Because valve  5100 C is closed, second solenoid  5100 B can be either in its first configuration or second configuration. In this configuration and operational state, fluid flows from the external environment  150  (e.g., through air inlet  732  of the fluid distributor  720 ) through fluid line  604 , through pump(s)  600 H,  600 F, through fluid line  606 , through fluid distribution line  5120 , through the first port  5110 A of the first solenoid  5100 A, through the first solenoid  5100 A, through second port  5110 B of the first solenoid  5100 A, through tank line  5116 A, and to its ultimate destination (the fluid container  400  in this example). 
     In this example foot support system  5100 , the fluid container  400  is used to adjust (and in this example, increase) fluid mass, volume, and/or pressure in the first foot support bladders  200 A and  200 B. An example of an operational state for increasing fluid mass, volume, and/or pressure in first foot support bladder  200 A is shown in  FIG.  51 C . In this third operational state, first solenoid  5100 A is in the first configuration, the second solenoid  5100 B is in the first configuration, and the valve  5100 C is in the open configuration. Thus, when the fluid container  400  pressure is higher than the foot support bladder  200 A pressure, fluid flows from the fluid container  400 , through fluid line  5116 A, through the second port  5110 B of the first solenoid  5100 A, through the first solenoid  5100 A, through the first port  5110 A of the first solenoid  5100 A, through the fluid distribution line  5120 , through the first port  5114 A of the valve  5100 C, through the valve  5100 C, through the second port  5114 B of the valve  5100 C, through fluid line  5122 , through the first port  5112 A of the second solenoid  5100 B, through the second solenoid  5100 B, through the second port  5112 B of the second solenoid  5100 B, through fluid line  5118 A, and to its ultimate destination (the first foot support bladder  200 A in this example). 
     Additionally, in this example foot support system  5100 , the fluid container  400  is used to adjust (and in this example, increase) fluid mass, volume, and/or pressure in the second foot support bladder  200 B. An example of an operational state for increasing fluid mass, volume, and/or pressure in second foot support bladder  200 B is shown in  FIG.  51 D . In this fourth operational state, first solenoid  5100 A is in the first configuration, the second solenoid  5100 B is in the second configuration, and the valve  5100 C is in the open configuration. Thus, when the fluid container  400  pressure is higher than the foot support bladder  200 A pressure, fluid flows from the fluid container  400 , through the fluid line  5116 A, through the second port  5110 B of the first solenoid  5100 A, through the first solenoid  5100 A, through the first port  5110 A of the first solenoid  5100 A, through the fluid distribution line  5120 , through the first port  5114 A of the valve  5100 C, through the valve  5100 C, through the second port  5114 B of the valve  5100 C, through fluid line  5122 , through the first port  5112 A of the second solenoid  5100 B, through the second solenoid  5100 B, through the third port  5112 C of the second solenoid  5100 B, through fluid line  5118 B, and to its ultimate destination (the second foot support bladder  200 B in this example). 
     In some instances, it may be desired to remove fluid from the first foot support bladder  200 A in order to decrease pressure in the first foot support bladder  200 A (e.g., to provide a softer feel or for less intense activities, such as walking or casual wear).  FIG.  51 E  shows an example of this operational state. In this fifth operational state, the first solenoid  5100 A is in the second configuration, the second solenoid  5100 B is in the first configuration, and the valve  5100 C is in the open configuration. Thus, fluid flows from the first foot support bladder  200 A, through fluid line  5118 A, through the second port  5112 B of the second solenoid  5100 B, through the second solenoid  5100 B, through the first port  5112 A of the second solenoid  5100 B, through fluid line  5122 , through the second port  5114 B of the valve  5100 C, through the valve  5100 C, through the first port  5114 A of the valve  5100 C, through fluid distribution line  5120 , through the first port  5110 A of the first solenoid  5100 A, through the first solenoid  5100 A, through the third port  5   110 C of the first solenoid  5100 A, through fluid release line  5116 B, and to its ultimate destination (the external environment  150  in this example). 
     Also, in some instances, it may be desired to remove fluid from the second foot support bladder  200 B in order to decrease pressure in the second foot support bladder  200 B (e.g., to provide a softer feel or for less intense activities, such as walking or casual wear).  FIG.  51 F  shows an example of this operational state. In this sixth operational state, the first solenoid  5100 A is in the second configuration, the second solenoid  5100 B is in the second configuration, and the valve  5100 C is in the open configuration. Thus, fluid flows from the second foot support bladder  200 B, through fluid line  5118 B, through the third port  5112 C of the second solenoid  5100 B, through the second solenoid  5100 B, through the first port  5112 A of the second solenoid  5100 C, through the fluid line  5122 , , through the second port  5114 B of the valve  5100 C, through the valve  5100 C, through the first port  5114 A of the valve  5100 C, through fluid distribution line  5120 , through the first port  5110 A of the first solenoid  5100 A, through the first solenoid  5100 A, through the third port  5110 C of the first solenoid  5100 A, through fluid release line  5116 B, and to its ultimate destination (the external environment  150  in this example). 
     This example foot support system  5100  of  FIGS.  51 A- 51 F  does not have an operational state in which fluid moves from the external environment  150  directly into a foot support bladder  200 A,  200 B. Rather, in the foot support system  5100  of  FIGS.  51 A- 51 F , fluid pressure is increased in the foot support bladders  200 A,  200 B only by fluid transfer from the fluid container  400  to the foot support bladder  200 A,  200 B (as shown by the operational states of  FIGS.  51 C and  51 D ). Further, this example foot support system  5100  of  FIGS.  51 A- 51 F  does not have an operational state in which fluid moves from the fluid container  400  directly to the external environment  150  (e.g., to reduce pressure in container  400 ). Rather, the pressure in container  400  can be reduced, for example, by moving fluid from the container  400  to one of the foot support bladders  200 A,  200 B ( FIGS.  51 C and  51 D ) and then moving fluid from the bladder  200 A,  200 B to the external environment  150  ( FIGS.  51 E and  51 F ). If necessary or desired, fluid container  400  may include a check valve or a pressure relief valve (“PRV”) that opens to the external environment  150  to prevent over-pressurization of the fluid container  400  (rather than having excess fluid from container  400  passing through bladder(s)  200 A and/or  200 B to reduce pressure in the fluid container  400 ). Additionally or alternatively, if fluid pressure from the fluid source (e.g., fluid pressure generated by one or more foot activated pumps  600 H,  600 F) is insufficient or below the fluid pressure in open fluid pathways to the fluid container  400 , fluid will not transfer from the source to the fluid container  400 . Still additionally or alternatively, other pressure relief valves and/or fluid pathways may be provided at one or more locations in the overall fluid flow control system, foot support system  5100 , sole structure  104 , and/or article of footwear  100  to prevent over-pressurization of any part of the systems (e.g., to relieve pressure from fluid discharged by pump(s)  600 H,  600 F if there is no other place for the fluid to go without causing and/or risking damage). 
     The foot support systems  5100  described above in conjunction with  FIGS.  51 A- 51 F  may be used in articles of footwear, footwear sole structures, systems, and/or methods of any of the types described above in conjunction with  FIG.  1 - 50 B . Further, such foot support systems  5100  may include a power source, e.g., for powering one or more of solenoids  5100 A,  5100 B, and/or valve  5100 C. The power source may constitute one or more batteries  2602 , e.g., as described above. When necessary (e.g., under operation of a microprocessor of the types described above), the power source may: (a) switch the first solenoid  5100 A between its first configuration and its second configuration, (b) switch the second solenoid  5100 B between its first configuration and its second configuration, (c) unlatch the first solenoid  5100 A to allow it to change from its first configuration to its second configuration (or vice versa), (d) unlatch the second solenoid  5100 B to allow it to change from its first configuration to its second configuration (or vice versa), and/or (e) hold (e.g., temporarily) the valve  5100 C in the open configuration, etc. 
     As described above, the fluid distribution systems and foot support systems  5100  of  FIGS.  51 A- 51 F  may include one or more pumps  600 H,  600 F, e.g., as part of a fluid supply. When two pumps  600 H,  600 F are provided, e.g., as described above in conjunction with  FIG.  3 A , an outlet  600 HO of the first pump  600 H may be in fluid communication with an inlet  600 FI of the second pump  600 F, and an outlet  600 FO of the second pump  600 F may be in fluid communication with the first port  5110 A of the first solenoid  5100 A. 
     Additionally or alternatively, fluid distribution systems and/or foot support systems  5100  of the types described above in conjunction with  FIGS.  51 A- 51 F  may be contained or at least partially contained within a housing, engaged with a manifold, and/or otherwise engaged together or “packaged” as a component to enable incorporation into a sole structure and/or article of footwear as a unit. Note, for example, housings  502  and/or  750  of fluid distributors  500  described above.  FIG.  51 A  shows various examples of components that may be at least partially contained within and/or engaged with a housing  502 ,  750  in accordance with at least some examples of this technology. For example, the interior dashed line box (with long dashes)  5150 A schematically illustrates a housing (e.g.,  502 ,  750 ) that may contain solenoids  5100 A,  5100 B and valve  5100 C and the fluid lines connecting solenoids  5100 A,  5100 B and valve  5100 C. Another potential housing is schematically illustrated in  FIG.  51 A  by central “long dash-short dash” box  5150 B. The components contained within box  5150 B includes the components within box  5150 A and additionally the check valve  606 V.  FIG.  51 A  schematically illustrates another housing as broken line  5150 C. The example housing illustrated by broken line  5150 C includes the components contained within box  5150 B and additionally the pump(s) (e.g., a compressor, an electrically powered pump, etc.). Such housings (containing equipment within boxes  5150 A,  5150 B,  5150 C) may include openings, ports, hardware, fluid lines, and/or connectors for engaging fluid lines and/or for otherwise moving fluid into and out of the housings (e.g., moving fluid into and/or out of the ambient environment  150 , moving fluid into and/or out of tank  400 , moving fluid into and/or out of first foot support bladder  200 A, and/or moving fluid into and/or out of second foot support bladder  200 B, etc.). 
     III. Conclusion 
     The present invention is disclosed above and in the accompanying drawings with reference to a variety of embodiments. The purpose served by the disclosure, however, is to provide an example of the various features and concepts related to the invention, not to limit the scope of the invention. One skilled in the relevant art will recognize that numerous variations and modifications may be made to the embodiments described above without departing from the scope of the present invention, as defined by the appended claims. 
     For the avoidance of doubt, the present application, technology, and invention includes at least the subject matter described in the following numbered Clauses: 
     Clause 1. A fluid distribution system for an article of footwear, comprising:
     a first solenoid including a first port, a second port, and a third port;   a valve in fluid communication with the first port of the first solenoid; and   a second solenoid including a first port in fluid communication with the valve, a second port, and a third port;   wherein the first solenoid is independently switchable to: (a) a first configuration in which fluid flows through the first solenoid between the first port and the second port and (b) a second configuration in which fluid flows through the first solenoid between the first port and the third port,   wherein the valve is independently switchable to: (a) an open configuration in which fluid flows through the valve and (b) a closed configuration in which fluid does not flow through the valve,   wherein the second solenoid is independently switchable to: (a) a first configuration in which fluid flows through the second solenoid between the first port and the second port and (b) a second configuration in which fluid flows through the second solenoid between the first port and the third port, and   wherein simultaneous selective placement of: (a) the first solenoid in one of the first configuration or the second configuration, (b) the valve in one of the open configuration or the closed configuration, and (c) the second solenoid in one of the first configuration or the second configuration selectively places the fluid distribution system in a plurality of operational states.   

     Clause 2. The fluid distribution system according to Clause 1, wherein the plurality of operational states includes two or more of:
     (a) a first operational state in which the first solenoid is in the second configuration and the valve is in the closed configuration to move fluid from a fluid supply, through the first port of the first solenoid, and through the third port of the first solenoid,   (b) a second operational state in which the first solenoid is in the first configuration and the valve is in the closed configuration to move fluid from the fluid supply, through the first port of the first solenoid, and through the second port of the first solenoid,   (c) a third operational state in which the first solenoid is in the first configuration, the valve is in the open configuration, and the second solenoid is in the first configuration to move fluid from the second port of the first solenoid, through the first port of the first solenoid, through the valve, through the first port of the second solenoid, and through the second port of the second solenoid,   (d) a fourth operational state in which the first solenoid is in the first configuration, the valve is in the open configuration, and the second solenoid is in the second configuration to move fluid from the second port of the first solenoid, through the first port of the first solenoid, through the valve, through the first port of the second solenoid, and through the third port of the second solenoid,   (e) a fifth operational state in which the first solenoid is in the second configuration, the valve is in the open configuration, and the second solenoid is in the first configuration to move fluid from the second port of the second solenoid, through the first port of the second solenoid, through the valve, through the first port of the first solenoid, and through the third port of the first solenoid, and   (f) a sixth operational state in which the first solenoid is in the second configuration, the valve is in the open configuration, and the second solenoid is in the second configuration to move fluid from the third port of the second solenoid, through the first port of the second solenoid, through the valve, through the first port of the first solenoid, and through the third port of the first solenoid.   

     Clause 3. The fluid distribution system according to Clause 1 or 2, further comprising a first fluid line placing the first port of the first solenoid in fluid communication with the valve. 
     Clause 4. The fluid distribution system according to Clause 3, further comprising a check valve in the first fluid line to prevent fluid flow from the first solenoid or the from valve to a location outside the first fluid line. 
     Clause 5. The fluid distribution system according to any one of Clauses 1 to 4, wherein the fluid distribution system is switchable to be selectively placed in each of the first operational state, the second operational state, the third operational state, the fourth operational state, the fifth operational state, and the sixth operational state. 
     Clause 6. The fluid distribution system according to any one of Clauses 1 to 5, wherein the first solenoid is a latching three port, two state solenoid, wherein the valve is a normally closed non-latching solenoid, and wherein the second solenoid is a three port, two state solenoid. 
     Clause 7. The fluid distribution system according to any one of Clauses 1 to 5, wherein the first solenoid is a three port, two state solenoid, wherein the valve is a normally closed non-latching solenoid, and wherein the second solenoid is a three port, two state solenoid. 
     Clause 8. The fluid distribution system according to any one of Clauses 1 to 5, wherein the valve is a solenoid valve. 
     Clause 9. The fluid distribution system according to any one of Clauses 1 to 8, further comprising a power source for switching the first solenoid between the first configuration and the second configuration, for holding the valve in the open configuration, and for switching the second solenoid between the first configuration and the second configuration. 
     Clause 10. The fluid distribution system according to any one of Clauses 1 to 8, further comprising a power source for switching the first solenoid between the first configuration and the second configuration and for switching the second solenoid between the first configuration and the second configuration. 
     Clause 11. The fluid distribution system according to any one of Clauses 1 to 8, further comprising a power source supplying power at least to the first solenoid and the second solenoid. 
     Clause 12. The fluid distribution system according to any one of Clauses 9 to 11, wherein the power source includes a battery. 
     Clause 13. The fluid distribution system according to any one of Clauses 1 to 12, further comprising a first pump. 
     Clause 14. The fluid distribution system according to Clause 13, further comprising a second pump. 
     Clause 15. The fluid distribution system according to Clause 14, wherein an outlet of the first pump is in fluid communication with an inlet of the second pump, and wherein an outlet of the second pump is in fluid communication with the first port of the first solenoid. 
     Clause 16. The fluid distribution system according to any one of Clauses 1 to 15, further comprising a fluid supply line in fluid communication with the first port of the first solenoid. 
     Clause 17. The fluid distribution system according to any one of Clauses 1 to 16, further comprising a housing, wherein the first solenoid, the valve, and the second solenoid are at least partially contained in the housing. 
     Clause 18. The fluid distribution system according to any one of Clauses 1 to 17, further comprising a fluid line engaged with the second port of the first solenoid and configured to place the second port of the first solenoid in fluid communication with a fluid container. 
     Clause 19. The fluid distribution system according to any one of Clauses 1 to 18, further comprising a fluid line engaged with the third port of the first solenoid and configured to place the third port of the first solenoid in fluid communication with an ambient environment location. 
     Clause 20. The fluid distribution system according to any one of Clauses 1 to 19, further comprising a fluid line engaged with the second port of the second solenoid and configured to place the second port of the second solenoid in fluid communication with a first foot support bladder. 
     Clause 21. The fluid distribution system according to any one of Clauses 1 to 20, further comprising a fluid line engaged with the third port of the second solenoid and configured to place the third port of the second solenoid in fluid communication with a second foot support bladder. 
     Clause 22. A foot support system, comprising:
     a first foot support bladder;   a second foot support bladder;   a fluid container;   a fluid supply;   a first solenoid including a first port in fluid communication with the fluid supply, a second port in fluid communication with the fluid container, and a third port for releasing fluid from the foot support system;   a valve in fluid communication with the first port of the first solenoid; and   a second solenoid including a first port in fluid communication with the valve, a second port in fluid communication with the first foot support bladder, and a third port in fluid communication with the second foot support bladder;   wherein the first solenoid is independently switchable to: (a) a first configuration in which fluid flows through the first solenoid between the first port and the second port and (b) a second configuration in which fluid flows through the first solenoid between the first port and the third port,   wherein the valve is independently switchable to: (a) an open configuration in which fluid flows through the valve and (b) a closed configuration in which fluid does not flow through the valve,   wherein the second solenoid is independently switchable to: (a) a first configuration in which fluid flows through the second solenoid between the first port and the second port and (b) a second configuration in which fluid flows through the second solenoid between the first port and the third port, and   wherein simultaneous selective placement of: (a) the first solenoid in one of the first configuration or the second configuration, (b) the valve in one of the open configuration or the closed configuration, and (c) the second solenoid in one of the first configuration or the second configuration selectively places the foot support system in a plurality of operational states.   

     Clause 23. The foot support system according to Clause 22, wherein the plurality of operational states includes two or more of:
     (a) a first operational state in which the first solenoid is in the second configuration and the valve is in the closed configuration to move fluid from the fluid supply, through the first port of the first solenoid, through the third port of the first solenoid, and to a location outside the foot support system,   (b) a second operational state in which the first solenoid is in the first configuration and the valve is in the closed configuration to move fluid from the fluid supply, through the first port of the first solenoid, through the second port of the first solenoid, and into the fluid container,   (c) a third operational state in which the first solenoid is in the first configuration, the valve is in the open configuration, and the second solenoid is in the first configuration to move fluid from the fluid container, through the second port of the first solenoid, through the first port of the first solenoid, through the valve, through the first port of the second solenoid, through the second port of the second solenoid, and into the first foot support bladder,   (d) a fourth operational state in which the first solenoid is in the first configuration, the valve is in the open configuration, and the second solenoid is in the second configuration to move fluid from the fluid container, through the second port of the first solenoid, through the first port of the first solenoid, through the valve, through the first port of the second solenoid, through the third port of the second solenoid, and into the second foot support bladder,   (e) a fifth operational state in which the first solenoid is in the second configuration, the valve is in the open configuration, and the second solenoid is in the first configuration to move fluid from the first foot support bladder, through the second port of the second solenoid, through the first port of the second solenoid, through the valve, through the first port of the first solenoid, through the third port of the first solenoid, and to a location outside the foot support system, and   (f) a sixth operational state in which the first solenoid is in the second configuration, the valve is in the open configuration, and the second solenoid is in the second configuration to move fluid from the second foot support bladder, through the third port of the second solenoid, through the first port of the second solenoid, through the valve, through the first port of the first solenoid, through the third port of the first solenoid, and to a location outside the foot support system.   

     Clause 24. The foot support system according to Clause 22 or 23, further comprising a first fluid line placing the fluid supply in fluid communication with the first port of the first solenoid. 
     Clause 25. The foot support system according to Clause 22 or 23, further comprising a first fluid line placing the fluid supply in fluid communication with the first port of the first solenoid and placing the first port of the first solenoid in fluid communication with the valve. 
     Clause 26. The foot support system according to Clause 24 or 25, further comprising a check valve in the first fluid line to prevent fluid flow from the first solenoid or the from valve into the fluid supply through the first fluid line. 
     Clause 27. The foot support system according to any one of Clauses 22 to 26, wherein the foot support system is switchable to be selectively placed in each of the first operational state, the second operational state, the third operational state, the fourth operational state, the fifth operational state, and the sixth operational state. 
     Clause 28. The foot support system according to any one of Clauses 22 to 27, wherein the first solenoid is a latching three port, two state solenoid, wherein the valve is a normally closed non-latching solenoid, and wherein the second solenoid is a three port, two state solenoid. 
     Clause 29. The foot support system according to any one of Clauses 22 to 27, wherein the first solenoid is a three port, two state solenoid, wherein the valve is a normally closed non-latching solenoid, and wherein the second solenoid is a three port, two state solenoid. 
     Clause 30. The foot support system according to any one of Clauses 22 to 27, wherein the valve is a solenoid valve. 
     Clause 31. The foot support system according to any one of Clauses 22 to 30, further comprising a power source for switching the first solenoid between the first configuration and the second configuration, for holding the valve in the open configuration, and for switching the second solenoid between the first configuration and the second configuration. 
     Clause 32. The foot support system according to any one of Clauses 22 to 30, further comprising a power source for switching the first solenoid between the first configuration and the second configuration and for switching the second solenoid between the first configuration and the second configuration. 
     Clause 33. The foot support system according to any one of Clauses 22 to 30, further comprising a power source supplying power at least to the first solenoid and the second solenoid. 
     Clause 34. The foot support system according to any one of Clauses 31 to 33, wherein the power source includes a battery. 
     Clause 35. The foot support system according to any one of Clauses 22 to 34, wherein the fluid supply includes a first pump. 
     Clause 36. The foot support system according to Clause 35, wherein the fluid supply further includes a second pump. 
     Clause 37. The foot support system according to Clause 36, wherein an outlet of the first pump is in fluid communication with an inlet of the second pump, and wherein an outlet of the second pump is in fluid communication with the first port of the first solenoid. 
     Clause 38. The foot support system according to any one of Clauses 22 to 37, wherein the fluid supply includes an input line in fluid communication with external environment. 
     Clause 39. The foot support system according to any one of Clauses 22 to 38, wherein the fluid container includes a bladder for containing fluid. 
     Clause 40. The foot support system according to any one of Clauses 22 to 39, further comprising a housing, wherein the first solenoid, the valve, and the second solenoid are at least partially contained in the housing. 
     Clause 41. The foot support system according to any one of Clauses 22 to 40, wherein the first foot support bladder includes a heel support bladder region. 
     Clause 42. The foot support system according to any one of Clauses 22 to 41, wherein the second foot support bladder includes a forefoot support bladder region. 
     Clause 43. A sole structure, comprising:
     a sole base member; and   a foot support according to any one of Clauses 22 to 42, wherein at least one of the first foot support bladder and the second foot support bladder is engaged with and/or at least partially contained in the sole base member.   

     Clause 44. The sole structure according to Clause 43, wherein the sole base member comprises a midsole component. 
     Clause 45. The sole structure according to Clause 44, wherein the midsole component includes a foam material. 
     Clause 46. The sole structure according to any one of Clauses 43 to 45, wherein both of the first foot support bladder and the second foot support bladder are engaged with and/or at least partially contained in the sole base member. 
     Clause 47. The sole structure according to any one of Clauses 43 to 46, wherein the fluid container is engaged with and/or at least partially contained in the sole base member. 
     Clause 48. The sole structure according to any one of Clauses 43 to 47, wherein at least a portion of the fluid supply is engaged with and/or at least partially contained in the sole base member. 
     Clause 49. The sole structure according to any one of Clauses 43 to 48, wherein the first solenoid, the valve, and the second solenoid are at least partially contained in a housing, and wherein the housing is engaged with the sole base member. 
     Clause 50. An article of footwear, comprising:
     an upper; and   a sole structure according to any one of Clauses 43 to 49 engaged with the upper.