Patent Publication Number: US-11382382-B2

Title: Adjustable footwear

Description:
RELATED APPLICATIONS 
     This Application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 62/650,355, filed Mar. 30, 2018, entitled “ADJUSTABLE FOOTWEAR” and U.S. Provisional Application No. 62/756,111, filed Nov. 6, 2018, entitled “ADJUSTABLE FOOTWEAR”. The entire contents of these applications are incorporated herein by reference in their entireties. 
    
    
     FIELD 
     Disclosed embodiments are related to footwear with adjustable portions to accommodate feet of different sizes and shapes. 
     BACKGROUND 
     Traditionally, footwear is manufactured and sold as symmetrical same-size pairs of shoes. Typically, this footwear generally includes a substantially rigid sole and upper, such that the footwear may be worn comfortably if the shoes are correctly sized for a person. Conventional footwear generally has some adjustability or securement element, including laces, straps, etc. which allow a wearer to secure the correctly sized shoe to a foot. However, traditional footwear has a substantially fixed height, width, and length which aren&#39;t independently adjustable to accommodate variations in foot size. 
     SUMMARY 
     According to one embodiment, an adjustable footwear article includes a sole having a lower tread surface, an upper footbed, and an outer periphery. The footwear article also includes an upper portion secured to said outer periphery of said sole and having a top panel that is only releasably or adjustably secured to said outer periphery of said sole. An entirety of said top panel is adjustable upwardly away from said upper footbed. 
     According to another embodiment, an adjustable footwear article includes a sole having a lower tread surface, an upper footbed, and an outer periphery. The footwear article also includes an upper portion secured to said outer periphery of said sole, said upper portion including: a forward panel portion having at least two expandable forward portions positioned on opposite sides of a longitudinal axis of the footwear article, a rearward panel portion at least two expandable rearward portions positioned on opposite sides of the longitudinal axis, and an upwardly-repositionable upper toe portion releasably secured to a lower toe portion that extends upwardly from said outer periphery of said sole at a forward end portion thereof. 
     According to yet another embodiment, an adjustable footwear article includes a sole having a lower tread surface, an upper footbed, and an outer periphery. The footwear article also includes an upper portion secured to said outer periphery of said sole, said upper portion including: a forward toe panel including an upwardly raisable tongue portion, left and right side panels extending upwardly from respective left and right sides of said outer periphery of said sole, and located generally behind said forward toe panel, and left and right forward cross-panels secured to said sole at respective opposite sides of said forward toe panel. Each of the left and right forward cross-panels include a respective distal end portion that is selectively securable at different locations along respective ones of said right and left side panels. The tongue portion is upwardly raisable when said distal end portions of said left and right forward cross-panels are detached from said right and left side panels. The left and right side panels are expandable laterally outwardly when their respective distal end portions are detached from said right and left side panels. 
     According to still yet another embodiment, an adjustable shoe includes a sole with a lower surface and an outer periphery and an adjustable upper secured to at least a portion of the outer periphery. The adjustable upper includes a toe portion constructed and arranged to expand vertically and longitudinally relative to the sole and a heel portion constructed and arranged to expand laterally and longitudinally relative to the sole. The toe portion and heel portion are independently expandable relative to one another. 
     According to still yet another embodiment, an adjustable shoe includes a sole with a lower surface and an outer periphery and an adjustable upper secured to at least a portion of the outer periphery. The adjustable upper includes at least one side panel constructed and arranged to expand laterally and vertically relative to the sole. The at least one side panel includes two separate attachment regions configured to secure the at least one side panel to the outer periphery. The adjustable upper also includes a toe portion constructed and arranged to expand vertically and longitudinally relative to the sole and a stretch liner secured to the at least one side panel and extending between the two separate attachment regions. The at least one side panel and toe portion are independently expandable relative to one another. 
     According to still yet another embodiment, an adjustable shoe includes a sole including a lower surface, a recess, and an outer periphery and an adjustable upper secured to at least a portion of the outer periphery, the adjustable upper expandable vertically, laterally, and longitudinally. The adjustable shoe also includes a removable footbed. An uppermost portion of the outer periphery is aligned with an uppermost portion of the removable footbed. 
     According to still yet another embodiment, an adjustable shoe includes a sole including a lower surface and an outer periphery and an adjustable upper secured to at least a portion of the outer periphery. The adjustable upper is expandable vertically, laterally, and longitudinally and is constructed and arranged to expand by up to 1.5 US shoe sizes. 
     According to still yet another embodiment, an adjustable shoe includes a sole including a lower surface and an outer periphery and an adjustable upper secured to at least a portion of the outer periphery. The adjustable upper is expandable in at least two directions selected from the group of vertical, lateral, and longitudinal and has a ball region expandability coefficient between or equal to 8% and 12%. 
     It should be appreciated that the foregoing concepts, and additional concepts discussed below, may be arranged in any suitable combination, as the present disclosure is not limited in this respect. Further, other advantages and novel features of the present disclosure will become apparent from the following detailed description of various non-limiting embodiments when considered in conjunction with the accompanying figures. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component that is illustrated in various figures may be represented by a like numeral. For purposes of clarity, not every component may be labeled in every drawing. In the drawings: 
         FIGS. 1A and 1B  are partial-top and side elevation views, respectively, of one embodiment of an adjustable shoe; 
         FIG. 2  is an exploded perspective view of a sole, toe panel, and heel portion of the adjustable shoe of  FIGS. 1A and 1B ; 
         FIGS. 3A and 3B  are partial-top and side elevation views, respectively, of another embodiment of an adjustable shoe with an enclosed heel portion; 
         FIGS. 4A and 4B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with an upper portion partially made up of separate straps; 
         FIGS. 5A and 5B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with a similar upper portion to the shoe of  FIGS. 1A and 1B ; 
         FIGS. 6A and 6B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable open shoe; 
         FIGS. 7A and 7B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable closed shoe; 
         FIGS. 8A and 8B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe; 
         FIGS. 9A and 9B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with an upper portion partially made up of separate straps; 
         FIGS. 10A and 10B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with an open back and expandable sections shown in a closed configuration; 
         FIG. 10C  is a perspective view of the adjustable shoe of  FIGS. 10A and 10B , in which the expandable sections are shown in an open configuration; 
         FIGS. 11A and 11B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with expandable sections shown in a closed configuration; 
         FIG. 11C  is a perspective view of the adjustable shoe of  FIGS. 11A and 11B , in which the expandable sections are shown in an open configuration; 
         FIGS. 12A and 12B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe similar to that of  FIGS. 11A-11C  and including a laced upper portion with expandable sections shown in a closed configuration; 
         FIG. 12C  is a perspective view of the adjustable shoe of  FIGS. 12A and 12B , in which the expandable sections are shown in an open configuration; 
         FIGS. 13A and 13B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe with expandable sections shown in a closed configuration; 
         FIG. 13C  is a perspective view of the adjustable shoe of  FIGS. 13A and 13B , in which the expandable sections are shown in an open configuration; 
         FIGS. 14A and 14B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe similar to that of  FIGS. 9A and 9B , with an upper portion including separate straps; 
         FIGS. 15A and 15B  are partial-top and side elevation views, respectively, of yet another embodiment of an adjustable shoe similar to that of  FIGS. 8A and 8B , with an upper portion including separate straps; 
         FIG. 15C  is a perspective view of the adjustable shoe of  FIGS. 15A and 15B , in which an adjustable multi-strap section is detached to facilitate upward expansion of a top panel; 
         FIGS. 16A and 16B  are top plan and side elevation views, respectively, of yet another embodiment of an adjustable shoe with a substantially continuous single upper panel; 
         FIG. 17  is a side elevation of yet another embodiment of an adjustable shoe; 
         FIGS. 18A-18D  depict various views of yet another embodiment of an adjustable shoe; 
         FIG. 18E  is a transverse cross-sectional view taken along taken along line  18 E- 18 E of  FIG. 18B . 
         FIGS. 19A-19D  depict various views of yet another embodiment of an adjustable shoe; 
         FIGS. 20A and 20B  are perspective and side elevation views, respectively, of yet another embodiment of an adjustable shoe; 
         FIGS. 21A and 21B  depict side elevation and bottom plan views, respectively, of one embodiment of a last for last testing an adjustable shoe; 
         FIGS. 22A-22B  depict a transverse cross-sectional view and a side elevation view, respectively, of one embodiment of an internal volume of an adjustable shoe calculated through last testing using the last of  FIGS. 21A-21B ; 
         FIG. 23A  depicts a bottom plan view of another embodiment of a last for last testing an adjustable shoe; and 
         FIG. 23B  depicts a side elevation view of another embodiment of an internal volume of an adjustable shoe calculated through last testing using the last of  FIG. 23A . 
     
    
    
     DETAILED DESCRIPTION 
     Footwear is traditionally manufactured and sold in symmetrical pairs. In many cases, people have asymmetrical and/or differently sized feet. Feet may have variations in length, width, or height permanently or as a part of a temporary condition. Various conditions may cause asymmetric size variations in feet, including foot or ankle surgery, bone spurs, bunions, hammer toe, or edemas caused by arthritis, diabetes, treatment of cancer, or other circulatory and vascular conditions. When size change of the feet occurs, either symmetric or asymmetric, people will commonly purchase additional pairs of shoes of different sizes. In the case of asymmetric swelling, a person may use one shoe from a differently sized pair or will purchase one pair of shoes that is large enough for the larger foot (i.e., swollen foot) and wear an oversized shoe on the unswollen foot. In certain cases, people may resort to a medical boot on the larger or more swollen foot, thereby creating an obvious asymmetrical appearance and potentially drawing undesired public attention to asymmetry and/or a medical condition. 
     In view of the above, the inventors have recognized the benefits of adjustable footwear which allows for length, width, and height adjustment of a shoe. More specifically, the inventors have recognized the benefits of adjustable footwear which allows for expansion of the toe portion, upper, and heel portion to accommodate temporary or permanent variations in foot size or shape. 
     According to one embodiment, an adjustable shoe includes an adjustable upper with a toe portion, side panel, and heel portion which can be adjusted inwardly or outwardly to accommodate size variations (e.g., swelling) in different regions of a wearer&#39;s foot. The adjustable shoe can have the adjustable components tightened or loosened in multiple directions to allow a wearer to accommodate temporary or chronic swelling or other foot shape variations. Once adjusted as desired, matching pairs of adjustable shoes or other footwear articles may be worn in such a way as to present a generally symmetrical appearance to an outside viewer. That is, the adjustable shoe may accommodate foot size variations without the need for differently sized shoe pairs or specialized medical footwear. The adjustable shoe may be readjusted as needed to accommodate various permanent or temporary foot conditions. 
     In some embodiments, an adjustable shoe includes an adjustable toe portion. The toe portion may be adjustable upwardly, lengthwise, or laterally relative to a sole or footbed of the shoe. Accordingly, the toe portion region may be adjusted to accommodate size variations or swelling at the front of the foot in three dimensions: height, width, and length. In certain embodiments, different portions of the toe portion region may have different adjustment directions. For example, a first region may be arranged for height adjustment, whereas a second region is arranged for height, length, and lateral adjustment. Accordingly, the first region may be constrained to accommodate variations in a single direction (i.e., height) of an adjacent first foot portion where the second region may be able to accommodate variations in all three directions (i.e., height, length, and width) of an adjacent second foot portion. Such an arrangement may allow the adjustable shoe to maintain additional support and protection for the foot in foot portions less likely to have size variations without compromising adjustability of the shoe in areas likely to accommodate said variations. 
     In some embodiments, an adjustable shoe includes an adjustable side panel. The side panel may be adjustable upwardly or laterally relative to a sole or footbed of the shoe. Accordingly, the side panel may be adjusted to accommodate width or height size variations in a midfoot region of a wearer&#39;s foot. In certain embodiments, the adjustable shoe may include two side panels formed as two independent walls separated by a longitudinal opening. According to this embodiment, as the walls are not directly connected, the walls may be adjusted laterally independent of the other. Thus, the side panel may accommodate different size variations that may occur on different sides of the midfoot region. In some embodiments, the side panel may include one or more sole attachment regions which connect the side panel to the sole of the shoe. The sole attachment regions may have a substantially short longitudinal length relative to the length of the sole such that the portion of the side panel attached to the sole is reduced. Such an arrangement may promote additional lateral adjustability without compromising structural support. Of course, the one or more sole attachment regions may have any suitable arrangement and length, as the present disclosure is not so limited. 
     In some embodiments, an adjustable shoe includes an adjustable heel portion. The adjustable heel portion may be adjustable laterally or longitudinally (i.e., lengthwise) relative to the sole or footbed of the shoe. Accordingly, the adjustable heel portion may accommodate length or width size variations in the heel or ankle region of a wearer&#39;s foot. The heel portion may include one or more regions which have different flexibility. For example, a region of the heel portion near the sole of the shoe may be stiffer than a region of the heel portion near the side panel. Accordingly, support for the foot may be provided while allowing for adjustability in areas prone to swelling or other foot size variations. 
     In some embodiments, an adjustable shoe with adjustable upper components including a toe portion, side panel, and heel portion may be independently (i.e. separated) from one another. For example, each of the adjustable shoe upper components may be attached to the sole or footbed separately, allowing each piece to move and be adjusted independently of the others. Accordingly, different portions of the shoe may be adjusted to accommodate different size variations in different areas of the foot. That is, a wearer can adjust a specific portion to improve the fit of the shoe without compromising the fit of other portions. In some embodiments, the toe portion, side panel, and heel portion may be connected by one or more connecting elements. The connecting elements may be laces, elastic bands, or any another suitable arrangement which allow the wearer to secure the shoe to the wearer&#39;s foot and adjust the shoe components relative to one another. In certain embodiments, the connecting elements may be releasably attachable between shoe components, such that the shoe components may be entirely separated for additional adjustability. According to this embodiment, the connecting elements may be secured with a knot, hook and loop fastener (e.g., Velcro), buttons, snaps, buckles, or any other suitable arrangement that allows for adjustable fastening. In some embodiments, the shoe components may be indirectly interconnected with stretch material (e.g., elastane, spandex, etc.) which allow the components to be expanded without reducing the volume of the shoe in another region. 
     In some embodiments, at least one of an adjustable toe portion, side panel, and heel may include one or more stretch portions. The stretch portions may be made of stretch material (e.g., elastane, spandex, etc.) which is distinct from the material for the toe portion, side panel, and heel. The one or more stretch portions may be positioned in areas of the shoe likely to accommodate foot size variations, especially in areas likely to accommodate temporary foot size variations due to swelling. For example, flexible portions may be beneficial around the upper forefoot, around the lower sides of the midfoot, or around the sides of the ankle. Of course, the stretch portions may be positioned at any suitable location, as the present disclosure is not so limited. 
     In some embodiments, an adjustable shoe may include a removable inset footbed. More specifically, the shoe may include a recessed cavity in the sole of the shoe to receive the footbed. Such an arrangement may have numerous benefits, including alignment of the bottom of the foot with the bottom of adjustable shoe components and support for custom orthotics. Without wishing to be bound by theory, alignment of the bottom of the foot and the bottom of the adjustable upper allows for adjustability of the upper without any interference from rigid components that may form the footbed or sole of the shoe. That is, there are no rigid shoe components that interfere with lateral, longitudinal, or vertical size variations of the foot. The recess in the sole of the adjustable shoe may provide support for foot orthoses (i.e., orthotics) which may be used in combination with the adjustable shoes to change the support provided for the wearer&#39;s foot. The orthotics may provide a substantially separate and independent function than the adjustable upper portions of the shoes. Due to the recess in the sole, the orthotic or conventional footbed may be received and held securely in the shoe, thereby improving comfort and function of the footbed. Of course, the sole and footbed may have any suitable arrangement to allow for adjustability and expansion of an adjustable upper, as the present disclosure is not so limited. 
     In some embodiments, an adjustable shoe upper including an adjustable toe portion, side panel, and heel may be composed of a strong, flexible material. For example, the upper may be made of canvas, leather, or any other suitable material that allows for adjustability. As discussed previously, the adjustable shoe may also include stretch materials in at least a portion of the adjustable upper, including, but not limited to, spandex, neoprene, elastane, latex, stretch fiber blends, or any other suitable stretch material. In some embodiments, the stretch material may be two-way stretch or four-way stretch depending on the position of the stretch material in the upper. Such an arrangement may allow for additional support or additional expansion for different areas of the foot. For example, it may be beneficial to have four-way stretch material in the toe portion area around the top of the foot to allow for additional expansion, while it may be beneficial to have two-way stretch material around the ankle to provide more ankle support. Of course, the stretch material may have any suitable stretch direction and be positioned in any suitable location in the adjustable upper, as the present disclosure is not so limited. In some embodiments, the sole of the shoe may be composed of rubber, polyurethane, leather, plastic, thermoplastic rubber, or any other suitable material with a desirable durability and flexibility for a given activity (e.g., walking, hiking, athletics, etc.). 
     In some embodiments, an adjustable shoe with an adjustable upper may allow for size expansion of the shoe, such that a shoe may effectively accommodate multiple nominal sizes of feet. For example, an adjustable upper may be expanded such that the overall length, width, and/or height of the foot containing volume corresponds to an increased nominal shoe size as measured in US shoe size, European shoe size, UK shoe size, Mondopoint, or any other suitable metric. Such an arrangement may be beneficial to accommodate permanent, chronic, or temporary foot size variations which may cause a nominal size change of the foot. In some embodiments, an adjustable upper may expand longitudinally and laterally to increase the nominal size of the adjustable shoe by up to 1.5 US shoe sizes. 
     Adjustable shoes as described herein may be beneficial for a wide variety of people. For example, those with medical conditions that may have frequent temporary swelling or size variations in their feet may wish to wear a single pair of shoes without personal modification or the need to buy multiple pairs. Similarly, those with differently sized feet or more permanent conditions like bunions or heel spurs may also want a single pair of shoes which adjust to the different shapes of their feet. Adjustable shoes may also be desirable for children, where a single pair of shoes may be worn for longer than a non-adjustable pair of shoes. Additionally, shoe wearers without significant foot size variations may also find the adjustable shoe more comfortable to wear than traditional footwear due to a more customized fit. Of course, adjustable shoes may be used for any desirable application, as the present disclosure is not so limited. 
     It should be appreciated that the flexibility of an upper of an adjustable shoe and any connecting elements will permit some limited relative movement of the panels when the shoe is secured to a foot. Accordingly, the terms “secure” or “secured”, as used herein, are intended to be relative and do not necessarily refer to rigidly fixed positions unless specifically stated as such. 
     Referring now to the drawings and the illustrative embodiments depicted therein, various types of adjustable shoes are disclosed, ranging from open sandals or sandal-like footwear ( FIGS. 1A-2, 4A, 4B, 5A, 5B, 14A and 14B ) to closed or substantially closed shoes ( FIGS. 3A, 3B, 7A-9B, 11A-12C, 15A-15C, 16A and 16B ), boots ( FIGS. 13A-13C and 18 ), and clogs ( FIGS. 10A-10C ). Each of the adjustable shoes may have a substantially conventional sole, which may have an average thickness as shown in  FIGS. 1A-2, 7A-18 , or which may be thinner or thicker than the average thickness as shown in  FIGS. 3A-6B , as desired. In each of the depicted embodiments, the adjustable shoes include an adjustable upper portion which is adjustable in at least one different areas (e.g., toe portion, side panel, heel portion), and in different directions in order to accommodate permanent or temporary size variations in feet (e.g., feet having temporarily or chronically swollen regions). Thus, matching pairs of adjustable shoes can be adjusted as desired to accommodate any feet asymmetries and size variations without a significant outward asymmetrical appearance. 
       FIGS. 1A-2  depict one embodiment of an adjustable shoe  100  which includes a conventional sole  102  with a lower tread surface  104 , an upper footbed  106 , and an outer periphery or perimeter region  108 , plus an upper portion  110  that is secured to the sole&#39;s outer periphery  108 . Upper portion  110  includes a top panel  112  that is adjustably secured to the outer periphery  108 . The top panel  112  forms a side panel and toe portion of the shoe. As shown in  FIG. 2 , top panel  112  is not sewn or otherwise permanently attached to the sole  102 , or to an upwardly-extending perimeter panel  114  of upper portion  110 . Instead, the top panel  112  is arranged as a separate, independent piece that is adjustable upwardly away from the upper footbed  106 . In addition, a separate heel portion  116  forming the heel portion is entirely separate and, together with top panel  112 , is secured to sole  102  with a flexible elongate connecting element  118  such as a lace, cord, cable, or any other suitable arrangement. The connecting element  118  extends through sole-mounted loops  120  and openings  122  formed in top panel  112  and heel portion  116 , and can be tied at a location above top panel  12  in order to secure top panel  112  and heel portion  116  relative to each other and relative to sole  102 . Accordingly, by adjusting the tension of the connecting element  118 , the top panel  112  and heel portion  116  may be adjusted or expanded relative to each out to accommodate foot size variations that may occur in the different regions of the foot. That is, the connecting element  118  may be loosened near particular openings  122  and tightened near other openings to substantially modify the shape of the interior volume of the upper portion  110  and accommodate foot size and shape variations. 
     As shown in  FIG. 2 , top panel  112  and heel portion  116  are entirely separate components that are only releasably or adjustably secured relative to sole  102 , with adjustability provided by adjusting the effective length of connecting element  118 , and with releasability provided by entirely removing connecting element  118  from the openings  112 . In some embodiments, the upper panels may be further secured to the sole, either in a non-releasable manner (e.g., by sewing) or in a releasable manner (e.g., with hook and loop fasteners). 
     As shown in  FIGS. 3A and 3B , another embodiment of a shoe  200  includes an adjustable upper which enables the shoe to accommodate foot size variations as described above. The shoe  200  includes releasable a top panel  212  with openings  222 . Shoe  200  includes a thick sole  202  that is substantially thicker than the sole of the shoe of  FIGS. 1A-2 . Shoe  200  further includes an upwardly-extending perimeter panel  214  that extends around an outer periphery  208  of sole  202 , to thereby surround a rear or heel portion of a wearer&#39;s foot for additional support. 
     In the embodiment depicted in  FIGS. 3A and 3B , top panel  212  is entirely separate from sole  202  and perimeter panel  214 , and is secured to perimeter panel  214  via a lace (not shown) or other connecting element that extends through corresponding pairs of openings  222  found in perimeter panel  214  and top panel  212 . Thus, by adjusting the tension and/or effective length of the lace or other flexible elongate securing member, the height of top panel  212  may be adjusted relative to sole  202  and perimeter panel  214 . This adjustment permits the wearer to increase or decrease the volume of space available for the wearer&#39;s foot inside the shoe  200 , and permits the wearer to selectively adjust the volume of space available for specific regions of the wearer&#39;s foot, by moving additional lace length in any regions of desired additional volume or space. For example, the wearer may slide additional lace length into the right side region of the shoe to permit lateral (i.e., rightward) expansion of the foot-receiving volume of the shoe  200 , such as to accommodate a foot that is swollen along its right-hand side. 
       FIGS. 4A and 4B  depict yet another embodiment of a shoe  300  for selective expandability of certain footwear regions achieved with the use of elastic materials including elastic strap portions. The shoe  300  includes at least four top straps  330  located rearward of a substantially fixed and closed toe panel  332 , and with a heel strap  334  extending rearwardly from a midsection of the sole  302 . Each of the top straps  330  has a proximal end portion secured to one side of the sole  302  via an attachment such as stitching or adhesive and a distal end portion  336  that is made up of elastic material and secured to an opposite side of the sole  302 . The remainder of each top strap  330  may be made from a substantially non-stretch material, including, but not limited to, leather, canvas, or woven nylon. Heel strap  334  has a generally non-stretch midsection  334   a  and opposite end portions  334   b  made of elastic material. Thus, each of top straps  330  and heel strap  334  have at least one end portion made up of stretchable material where the strap attaches to sole  302 . Optionally, a rearward end of closed toe panel  332  includes a stretchable panel or panel portion  338  where it attaches to sole  302 , to permit additional expansion in that region. It will be appreciated that the stretchable portions of the straps and panels of the shoe  300  provide automatic expansion of areas in which a wearer&#39;s foot shape requires additional volume in an upward, lateral, or rearward direction. 
       FIGS. 5A and 5B  depict yet another embodiment of a shoe  400  for selective expandability of an upper portion. The shoe  400  includes an upper similar to the embodiment depicted in  FIGS. 1A-2 , with an independent upper portion and heel portion which allow adjustability through selective effective length and tension adjustment of a flexible connecting element such as a lace. Compared to the embodiment of  FIGS. 1A-2 , the shoe  400  includes a thicker sole  402 . 
       FIGS. 6A and 6B  depict yet another embodiment of an adjustable shoe  500 . The shoe  500  utilizes an upwardly-extending perimeter panel  514  that extends around an outer periphery  508  of sole  502 , to thereby surround a rear or heel portion of a wearer&#39;s foot, rather than providing a separate heel portion in a similar manner to the embodiment depicted in  FIGS. 3A and 3B . As shown in  FIGS. 6A and 6B , upwardly-extending perimeter panel  514  partially overlaps a top panel  512  and is partially overlapped by the top panel  512 , and utilizes a connecting element  518  depicted in this embodiment as a lace to secure the separate top panel  512  relative to perimeter panel  514 . The relative length of the untied portion of connecting element  518  can be increased overall to provide additional volume for a wearer&#39;s foot, and can be lengthened in localized areas to permit regional expansion in a similar manner as described above. 
       FIGS. 7A and 7B  depict yet another embodiment of an adjustable shoe  600 . The adjustable shoe includes a top panel  612  and a perimeter panel  614  which form the side and heel portion of the shoe. The perimeter panel includes one or more expansion joints  640  positioned in various locations in the panels. The expansion joints may be utilized for general or localized expansion or retraction of the top panel  612  and/or perimeter panel  614 . Shoes may also utilize expandable or length-adjustable portions to provide additional volume in localized areas. As shown in  FIGS. 7A and 7B , the expansion joints may be arranged as Z-shaped folds. Accordingly, as additional expansion is required, the Z-shaped folds may unfurl to allow for additional length of panel material. Of course, any suitable arrangement for the expansion joints may be employed such that additional material is available for panel expansion. The adjustable shoe  600  also includes a connecting element  618  for securing the shoe to a wearer&#39;s foot, in addition to allowing the panels to be expanded by adjusting the effective length or tension of the connecting element. As shown in  FIGS. 7A and 7B , the connecting element  618  may be arranged as a flexible strap or band. 
       FIGS. 8A and 8B  depict yet another embodiment of an adjustable shoe  700 . The adjustable shoe  700  includes a left forward cross-panel  770  and right forward cross-panel  772  each secured to the sole  702  at respective opposite sides of a forward toe panel  712 . Each of the left and right forward cross-panels  770 ,  772  includes a distal end portion  770   a ,  772   a  that is selectively securable at different locations along side panels  714 . An optional tongue portion  774  is associated with each forward toe panel  712  and is upwardly raisable when the distal end portions of the cross-panels are detached from the side panels  714 . The left and right forward cross-panels  770 ,  772  are expandable laterally outwardly when their respective distal end portions  770   a ,  772   a  are detached from the side panels  714 . The respective distal end portions  770   a ,  772   a  are selectively securable at different locations along the side panels  714  using hook and loop fasteners (e.g., Velcro) as shown or any other suitable releasable fastener. The left and right forward cross panels  770 ,  772  may be slidably interconnected, such that each panel may move independently relative to the other in at least one direction. Accordingly, the cross-panels  770 ,  772  may be adjusted independently to accommodate foot size variations. In other embodiments, such as the embodiment depicted in  FIGS. 15A-15C , the cross-panels may overlay one another without any interconnection, such that the cross panels may be independently adjustable relative to one another in all directions. As shown in  FIG. 15C , the toe panel  1412  may be connected to the sole near the front of the toe portion, with the tongue  1474  separated entirely from the sole to allow additional upward adjustability of the tongue and toe panel. 
       FIGS. 9A and 9B  depict yet another embodiment of an adjustable shoe  800 . The adjustable shoe includes a series of adjustable-length straps  860 . As shown in  FIG. 9B , the straps  860  are horizontal straps which are vertically stacked and coupled to respective forward straps  862  to provide lateral, longitudinal (i.e., lengthwise), and vertical adjustability. Each strap  860  terminates at a respective forward end portion  860   a  that is adjustably securable to itself at different positions corresponding to different lengths after looping through a rearward end portion  862   a  of the forward straps  862 . As shown in  FIGS. 9A and 9B , the uppermost horizontal strap  860  and the uppermost forward strap  862  cooperate to define the forward end portion of the upper foot opening for each shoe  800 , such that that the longitudinal location of the uppermost forward strap  862  can be adjusted to accommodate large or swollen foot regions at different longitudinal locations along a wearer&#39;s foot. Additionally, such an arrangement allows adjustment of the toe portion via adjustment of the lower adjustable-length horizontal straps  860  and the corresponding forward straps  862 .  FIGS. 14A and 14B  depict another embodiment of an adjustable shoe  1300  with a similar structure to the embodiment of  FIGS. 9A and 9B . Compared to the embodiment of  FIGS. 9A and 9B , the embodiment of  FIGS. 14A-14B  the perimeter panel  1314  is closer to the sole  1302 , thereby allowing adjustment and expansions of the straps  1360  along a lower vertical position of the foot. 
       FIGS. 10A-10C  depict yet another embodiment of an adjustable shoe  900 . The adjustable shoe  900  includes a perimeter panel  914  and a top panel  912  each with a number of expansion joints  950 . As shown in  FIGS. 10A-10B , the expansion joints  950  are closed with a zipper  952  in a closed position such that the top panel  912  and perimeter panel  914  are not significantly expandable. As shown in  FIG. 10C , the zipper  952  is in an open position with the expansions joints  950  open and expandable. Without wishing to be bound by theory, such an arrangement allows a wear to quickly and easily adjust the amount of expansion of the top and bottom panels. Similar to the embodiment depicted in  FIGS. 7A and 7B , the expansion joint may be composed of folded, flexible material which unfurls to expand the perimeter and side panels when the zipper is opened. Expansion joints  950  may be formed from a substantially non-stretch material, such as the same or similar material as perimeter panels  914 , and top panels  912  or a thinner and more flexible material for comfort. Optionally, the expansion joints  950  may be formed from stretchable material to provide added expansion in certain regions of the shoes as desired. 
       FIGS. 11A-11C  depict yet another embodiment of an adjustable shoe  1000 . The adjustable shoe  1000  includes an expandable top panel  1012  and a perimeter panel  1014  including an expansion joint  1050  and a zipper  1052  similar to the embodiment of  FIGS. 10A-10C  as described above. Compared with the embodiment of  FIGS. 10A-10C , the embodiment of  FIGS. 11A and 11B  includes a heel portion formed as part of the perimeter panel  1014  which includes a heel expansion joint  1040  and a heel strap  1042 . The heel strap  1042  may have a proximal end secured to a first side of the heel portion and a distal end releasably attachable to a second side of the heel portion. As shown in  FIGS. 11A and 11B , the heel strap is releasably attached to the second side with a hook and loop fastener (e.g., Velcro), thereby securing the expansion joint  1040  to substantially prevent expansion. The heel strap allows for adjustability and expansion of the perimeter panel  1014 , especially the heel portion, to accommodate ankle swelling or any other longitudinal (i.e., lengthwise) swelling of the foot. As shown in  FIG. 11C , the heel strap  1042  is released, thereby allowing expansion joint  1040  to expand through unfurling of folded material. Without wishing to be bound by theory, such an arrangement may allow the perimeter panel  1014  to expand outward past a boundary defined by a sole of the shoe, thereby effectively increasing the size to accommodate foot size variations. 
       FIGS. 12A-12C  depict yet another embodiment of an adjustable shoe  1100 . The adjustable shoe includes an expandable top panel  1112  and a perimeter panel  1114  including an expansion joint  1150 , heel expansion joint  1140 , zipper  1152 , and heel strap  1142  similar to the embodiment of  FIGS. 11A-11C  as described above. Compared to the embodiment of  FIGS. 11A-11C , the embodiment of  FIGS. 12A-12C  includes a tongue  1174  and a connecting element  1118  which adds additional adjustability to the top panel  1112 . The tongue and connecting element allow the perimeter panel to be adjusts laterally outward and upward to accommodate width and height size variations in feet. 
       FIGS. 13A-13C  depict yet another embodiment of an adjustable shoe  1200 . Similar to the embodiments of  FIG. 11A-12C  as described above, the shoe  1200  includes an adjustable top panel  1212  and perimeter panel  1214 . Expansion joints  1250  are positioned between the top panel  1212  and the perimeter panel  1214  and are opened or closed by a zipper  1252  to selectively allow expansion in different regions of the shoe. As shown in  FIGS. 13A-13C , the shoe  1200  includes an adjustable ankle region including ankle expansion joints  1240  and ankle straps  1242 . The ankle expansion joints allow the ankle region to be adjusted laterally and longitudinally outward to accommodate any ankle size variations. 
       FIGS. 16A and 16B  depict yet another embodiment of an adjustable shoe  1500 . The adjustable shoe  1500  includes a continuous top panel  1512  and perimeter panel  1514 . That is, in the embodiment depicted in  FIGS. 16A and 16B , the top panel  1512  and perimeter panel  1514  are a continuous piece of material connected around the perimeter of a sole. A connecting member  1518 , depicted here as a band extends through around the circumference of the perimeter panel  1514  and top panel  1512 . Expansion joints  1540  formed as a folded flexible material are disposed along the perimeter panel  1514  and top panel  1512  and are opened or closed by adjusting the effective length and/or tension of the connecting member  1518 . Without wishing to be bound by theory, such an arrangement allows for lateral, longitudinal, and vertical adjustment and expansion with a single connecting member. 
       FIG. 17  depicts yet another embodiment of an adjustable shoe  1600 . The adjustable shoe  1600  includes a top panel  1612 , perimeter panel  1614 , and heel portion  1616 . The top panel  1612  and the heel portion each include fastener tabs  1648  constructed as hook and loop fasteners and arranged to releasably attach the top panel and the heel portion to the perimeter panel  1614 . The fastener tabs allow the top panel  1612  and heel portion  1616  to be adjusted upward and longitudinally, while the fastener tabs allow the perimeter panel  1614  to be adjusted laterally outward. The heel portion  1616  and perimeter panel  1614  are connected to the sole with stitching, while top panel  1612  is detached from the sole entirely. The top panel  1612  and heel portion  1616  each include an expansion joint  1640  which are connected by an elastic panel  1680 . Accordingly, both the elastic and expansion joints provide additional expandability of the heel portion  1616  and around the ankle region. 
       FIGS. 18A-18E  depict yet another embodiment of an adjustable shoe  1700 . The adjustable shoe includes a sole  1702  and an adjustable upper  1710  with an adjustable toe portion  1712 , side panels  1714 , and adjustable heel portion  1716 . The adjustable toe portion  1712  includes a panel  1713  secured at the toe end  1713   a  to the toe  1702   a  area of the sole  1702  and an opening  1722  disposed at a distal end  1713   b  of the toe panel  1713  for receiving a connecting element  1718   a . The adjustable shoe includes two side panels  1714  secured to the sole on opposite lateral sides of the shoe. Each side panel is arch-shaped and includes at least two separate attachment regions  1714   a ,  1714   b , with the forward attachment region  1714   b  being attached to a toe end region of the sole and the rearward attachment region  1714   a  being attached to a heel end region of the sole such that at least a mid-portion  1714   c  of the side panel is free from direct attachment to the sole. Without wishing to be bound by theory, such a construction allows for the side panels to bend outward more easily at the mid-portion to more readily adjust to varying widths of a wearer&#39;s foot. Each side of the adjustable side panels includes at least one opening  1722  for receiving at least one connecting element  1718   a ,  1718   b . The heel portion  1716  is secured to heel  1702   b  of the sole and includes at least one opening  1722  for receiving a connecting element  1718   b . The heel portion  1716  includes an upper edge  1716   a  and side edges or wings  1716   b . The heel portion also includes a lower edge  1716   c  that is connected directly to the sole. 
     The toe portion, side panels, and heel portion are independent and moveable relative to each other, as each is independently secured to the sole. As is clearly shown in  FIGS. 18A-18C , the connecting elements  1718   a ,  1718   b  releasably secure the toe portion to the side panel and the heel portion to the side panels, respectively. The connecting elements may be a lace, elastic band, or any other suitable arrangement for allowing a wearer to adjust the relative positioning of the adjustable upper components. As depicted in  FIGS. 18A-18E , the connecting elements  1718   a ,  1718   b  are constructed as an elastic lace. The connecting members,  1718   a ,  1718   b  include locks  1790   a ,  1790   b  which may be used to adjust the tension and/or effective length of the connecting members. As depicted in  FIGS. 18A-18E , the locks  1790   a ,  1790   b  are arranged as spring-loaded cord locks, although any suitable arrangement may be employed, such as knots or other releasable fasteners. Without wishing to be bound by theory, by adjusting the tension and/or effective length of the connecting element in different areas of the shoe, the adjustable upper  1710  may expand or contract to accommodate size variations in different regions of the wearer&#39;s foot. 
     Continuing with  FIGS. 18A-18B , the adjustable shoe  1700  includes a stretch liner  1780 . The stretch liner may be formed as a single component or multiple components. In one embodiment, the stretch liner  1780  includes a tongue liner  1782  and side liners  1783 . With respect to the side liners  1783 , a lower edge  1783   a  is attached along an outer periphery  1708  of the sole  1702  such that the side liner  1783  covers any gaps between the side panel attachment regions  1714   a  and  1714   b . In one embodiment, a lower edge  1782   a  of the tongue liner  1782  is attached to the sole such that the tongue liner covers any gaps between the toe portion  1712  and side panels  1714 . Thus, the stretch liner is connected adjacent to the toe portion  1712  along the outer periphery of the sole, but is not directly attached to the toe portion. In this respect no portion of the inner surface of the toe panel  1713  is attached to the opposing surface of the liner. Optionally, the stretch liner  1780  may be arranged to cover the gaps between the side panels  1714  and the heel portion  1716  such that a wearer&#39;s foot is not visible. Without wishing to be bound by theory, the stretch liner allows for any temporary or permanent foot size variations while enclosing the foot. The adjustable upper  1710  may be adjusted around various regions of the shoe to provide support to the foot without impeding expansion provided by the stretch liner. In some embodiments, the adjustable upper may be composed of a more rigid, non-stretch fabric or material, such that the adjustable upper may be tightened or loosened in discrete regions of the foot for support while allowing for the combined expansion of the stretch liner and adjustable upper to accommodate any swelling or other medical conditions. 
     According to the embodiment depicted in  FIGS. 18A-18E , the adjustable upper  1710  allows for expansion and adjustment in three directions, namely the length direction, the height direction and the width direction. The adjustable toe portion  1712  allows for longitudinal and vertical adjustment through manipulation of tension and/or effective length on the connecting member  1718   a  through the opening  1722  positioned on a distal end of the toe portion. That is, the toe portion  1712  may be moved longitudinally (i.e., lengthwise) to allow for size variations in the length of the foot, and may be moved upwardly (i.e., vertically) to allow for size variations in the height of the foot near the toes. The adjustable side panels  1714  allow for vertical and lateral adjustment through manipulation of the tension and/or effective length of the connecting member  1718   a . That is, the upper edges of the side panels may be moved laterally (i.e. widthwise) to allow for size variations in the width of the foot as well as upwardly (i.e., vertically) to allow for size variations in the height of the midfoot. As can be appreciated, this is accomplished by fixing the lower edge of the side panel to the sole whereas the upper free edge of the side panel is moveable. The adjustable heel portion  1716  allows for longitudinal and lateral adjustment through manipulation of tension and/or effective length on the connecting member  1718   b  through the opening  1722  positioned on the heel portion. That is, the upper edge  1716   a  of the heel portion may be moved longitudinally (i.e., lengthwise) to allow for size variations in the length of the foot, and the side edges or wings  1716   b  of the heel portion may be moved laterally (i.e., widthwise) to allow for size variations in the width of the foot near the ankle and heel. Thus, the adjustable upper can accommodate a wide variety of permanent and temporary foot shapes with a simple adjustment of the connecting members  1718   a ,  1718   b . According to one embodiment, the shoe  1700  may effectively expand up to 1.5 US shoe sizes to accommodate any foot size increase or foot size variations. 
     As shown best shown in  FIG. 18E , which is a transverse cross sectional view taken along line  18 E- 18 E of  FIG. 18B , the adjustable shoe  1700  includes an inset footbed  1706 . More specifically, the footbed  1706  is positioned in a recess  1703  in the sole  1702 , such that an uppermost portion of the footbed  1706  is effectively aligned height-wise with an uppermost portion of the outer periphery  1708  of the sole  1702  (at approximately dashed line A). Accordingly, when the shoe  1700  is worn, the bottom of a foot will be effectively aligned with an uppermost portion of the outer periphery  1708  of the sole  1702 . As the flexible or movable portions of the adjustable upper  1710  and stretch liner  1780  begin at the uppermost portion of the outer periphery, the only non-adjustable boundary of a foot-containing volume is the footbed  1706 . Thus, the adjustable upper  1710  may expand to account for any height, length, or width foot size changes without any non-adjustable portion of the shoe (e.g., the sole  1702 ) impeding the expansion. In some embodiments, the footbed  1706  may be removable, such that the footbed may be replaced with a custom orthotic. Thus, any orthotic may be securely received by the recess  1703  while providing the adjustability and expansion of the upper  1710 . 
       FIGS. 19A-19D  depict yet another embodiment of an adjustable shoe  1800 . The adjustable shoe  1800  includes a sole  1802  and an adjustable upper  1810  with a toe portion  1812 , side panels  1814 , and heel portion  1816 . The toe portion  1812  includes a panel  1813  secured at the toe end  1813   a  to the toe  1802   a  area of the sole  1802 . Accordingly, other than the attachment between the toe portion  1812  and the sole  1802  along the outer periphery  1808 , the toe portion is free to move relative to the rest of the shoe. Without wishing to be bound by theory, such an arrangement may allow for additional longitudinal and vertical expandability of the toe portion. The side panels  1814  are secured to the sole  1802  along a midfoot region  1802   c  of the sole  1802 . As best shown in  FIG. 19C , each side panel  1814  includes an elastic strap  1830  which is secured to the sole on a proximal end adjacent the side panel and includes a strap fastener  1844 . The elastic strap fastener  1844  is configured to releasably attach to the opposing side panel. That is, a first elastic strap extends from a first side where it is attached to the sole  1802  adjacent a first panel to a second side where it is releasably attached to a second side panel via the strap fastener  1844 . Similarly, a second elastic strap extends from the second side to the first side panel. Accordingly, the elastic straps  1830  may be used to secure the shoe  1800  to a wearer&#39;s foot and allow a user to adjust the width and height of the side panels. In the embodiment depicted in  FIGS. 19A-19D , the strap fastener  1844  is a hook and loop fastener which allows the strap fastener to be attached in different positions for adjustability of the side panels  1814 . In other embodiments, any suitable releasable fastener that allows for adjustment of the elastic straps, such as snap fasteners or buttons may be employed. The side panels  1814  include openings  1822  for receiving a connecting element  1818  which is positioned around a perimeter of the heel portion  1816 . The heel portion  1816  is secured to heel  1802   b  of the outer periphery  1808  of the sole  1802  and includes an upper edge  1816   a  and a lower edge  1816   c  that is connected directly to the sole. The toe portion, side panels, and heel portion are independent from one another and secured to the sole separately. Accordingly, the toe portion, side panels, and heel portion are all adjustable and expandable independently to accommodate foot size variations. 
     In the embodiment depicted in  FIGS. 19A-19D , the shoe  1800  may be adjustable using a combination of the elastic straps  1830  and connecting member  1818  to expand in three directions. Automatic or manual adjustment of the elastic straps  1830  provides vertical and lateral adjustment of the side panels  1814 . In some embodiments, the elastic bands with be substantially stretchy, such that they may expand significantly along the length of the band. According to this embodiment, if any foot swelling or other foot size variations need to be accommodated in the vertical direction, the elastic straps may automatically stretch and expand the shoe. Similarly, as the elastic bands  1830  control the lateral adjustment of the side panels  1814 , any width size variations may also be accommodated through the automatic stretching of the elastic bands. Manual adjustment of the bands (i.e., releasing the strap fastener  1844 ) may provide additional expansion of the side panels  1814 . By adjusting the tension or effective length of the connecting member  1818  using lock  1890 , the heel portion  1816  is adjustable longitudinally or laterally to provide expansion in the heel or ankle region of a wearer&#39;s foot. As best shown in  FIG. 19D , the connecting member is connected through openings  1822  on the side panels  1814  and positioned around a perimeter of the heel portion  1816 . Accordingly, by reducing the effective length or increasing the tension of the connecting member  1818 , the heel portion may be brought closer towards the openings  1822 . In the opposite direction, increasing the effective length or decreasing the tension of the connecting member  1818  allows the heel portion  1816  to expand away from the openings  1822  and increase the length and/or width of the shoe in the ankle and heel region of a wearer&#39;s foot. As the toe portion  1812  is not connected to either side panels  1814  or heel panel  1816 , the toe portion is free to expand vertically or longitudinally automatically. Thus, the shoe  1800  allows for vertical, lateral, and longitudinal adjustment to accommodate foot size variations in various regions of a wearer&#39;s foot. According to the depicted embodiment, the shoe  1800  may effectively expand up to 1.5 US shoe sizes to accommodate any foot size increase or foot size variations. 
     As shown best in  FIGS. 19A-19B , the shoe  1800  includes a stretch liner  1880 . The stretch liner  1880  is attached along the outer periphery  1808  of the sole to cover any gaps between the various components of the adjustable upper  1810 , including the toe portion  1812 , side panels  1814 , and heel portion  1816 . In the embodiment depicted in  FIGS. 19A-19D , the stretch liner  1880  is connected to each of the side panels  1814 , between the side panels and the heel portion  1812 , and around the outer periphery  1808  of the toe  1802   a  of the sole  1802  along a lower edge  1880   a  of the stretch liner. That is, the stretch liner is connected around the outer periphery of the toe of the sole adjacent the toe portion, but is not directly attached to the toe portion. In this respect no portion of the inner surface of the toe panel  1813  is attached to the opposing surface of the liner. Accordingly, the stretch liner  1880  and the toe portion  1812  are independently adjustable relative to one another. As discussed previously, the stretch liner allows for any temporary or permanent foot size variations while fully enclosing the foot. 
       FIGS. 20A-20B  depict yet another embodiment of an adjustable shoe  1900 . The shoe  1900  is similar to the embodiment of an adjustable shoe depicted in  FIGS. 19A-19D , with the shoe including a sole  1902  and an adjustable upper  1910  with a toe portion  1912 , side panels  1914 , and heel portion  1916 . As discussed previously, the toe portion, side panels, and heel portion are independently adjustable relative to one another using elastic straps  1930  and a connecting member  1918 , such that the shoe may be adjusted to accommodate foot size variations in various regions of the shoe. As compared with the embodiment depicted in  FIGS. 19A-19D , the toe portion  1912  of shoe  1900  includes a fastener  1946  positioned on a distal end of the toe portion to releasably attach the toe portion to a stretch liner  1980 . According to the embodiment depicted in  FIGS. 20A-20B , the fastener is a hook and loop fastener. Of course, any suitable releasable fastener, such as a snap fasteners or a buttons may be used to attach the toe portion to the stretch liner. Thus, the fastener  1946  allows for manual adjustment of the toe portion  1912 , such that the toe portion may be expanded longitudinally or vertically. Additionally, the fastener  1946  may be attached to the stretch liner  1980  to indirectly connect the toe portion and the side panels  1914  such that additional support is provided to the foot when additional expandability is not needed (e.g., when swelling has subsided). 
     Without wishing to be bound by theory, the expandability of an adjustable shoe upper according to embodiments described herein may be characterized through last testing. For example, lasts with different dimensions in various regions (corresponding to various regions of the foot) may be tested for fit within an adjustable shoe of the same nominal size. The lasts may be measured in one or more areas so that the internal dimensions (e.g., volume) of the adjustable shoe may be measured as the shoe is expanded. That is, a last with larger dimensions in one or more regions may cause the adjustable shoe to expand to accommodate the larger dimension. Accordingly, by varying the dimensions of the lasts and comparing them to a nominal size, the expansion of the adjustable shoe may be measured in one or more directions (e.g., longitudinally, transverse, vertically, etc.). Additionally, the expandability of the shoe may be measured in terms of cross-sectional area expansion (transverse or longitudinally) or volumetric expansion. The dimensions of the last may be increased in one or more regions until the last is no longer accommodated by the adjustable shoe. The largest dimensions which fit in the adjustable shoe may be used to characterize the amount of expansion the adjustable shoe is capable of. In some embodiments, the bottom dimensions of the testing lasts may be held constant and the upper regions of the testing last (i.e., above the sole region of the last) may have varied dimensions. Without wishing to be bound by theory, such an arrangement may be desirable to characterize the swelling of a wearer&#39;s foot which typically swells in the upper regions away from the sole of the foot. That is, in some cases, the sole of an unswollen foot and a swollen foot may have approximately equivalent dimensions on the sole but vary in dimensions along the upper regions of the foot. 
       FIGS. 21A-21B  depict exemplary measurement regions of a last  2000  for performing last testing of an adjustable shoe to characterize volumetric expandability. As shown in  FIGS. 21A-21B , multiple measurements may be taken of the last with reference to each of the labeled lines.  FIG. 21A  depicts an elevation view of the last  2000 . In the embodiment shown in  FIG. 21A , the stick of the last may be measured as a linear distance between S 1  and S 2 . The circumference of various regions of the last may also be measured. In the embodiment shown in  FIG. 21A , the ball girth is a circumference measured in the region along the line G 1  to G 2 , the waist girth is measured in the region along line G 3  to G 4 , and the instep girth is measured in the region along line G 5  to G 6 . Each of these measurements may correspond to a circumference of the last along a particular transverse cross section. As shown in  FIG. 21A , the toe spring distance T 1  to T 2  may be measured as well as the toe thickness T 4  to T 5 . Similarly, the heel pitch distance H 1  to H 2  may also be measured. 
       FIG. 21B  depicts a plan bottom view of the last  2000 . As shown in  FIG. 21B , multiple measurements of the last may be taken along the bottom of the last to characterize the volume expandability of an adjustable shoe. The bottom length may be measured along L 1  to L 2 . The bottom width may also be measured along line W 1  to W 2  and the last bottom paper (LBP) heel width may be measured along line W 3  to W 4 . Approximate volumes may be calculated using these measurements and the other measurements described above, which may be useful for characterizing the expandability of the adjustable shoe. Of course, any suitable measurements of the last may be taken, as the present disclosure is not so limited. 
     Without wishing to be bound by theory, the measurements described with reference to  FIGS. 21A-21B  may be used to calculate approximate volumes which are useful for characterizing the expandability of an adjustable shoe upper. According to one embodiment, the ball girth, waist girth, and instep girth may be used to compute an approximate volume of the last corresponding to the internal volume of the adjustable shoe. In this embodiment, some assumptions are made for simplicity in calculating the approximate volume of the adjustable shoe. First, the transverse cross section corresponding to the measured girth is assumed to be circular. As a result, a computed radius of the circular cross section, r, is found from the equation: 
             r   =     G     2   ⁢   π             
where G is the measured circumference or girth in the specified region (e.g., ball, waist, instep). Accordingly, the calculated cross-sectional area of the internal volume of the shoe may be calculated by the equation:
 
             A   =       G   2       4   ⁢   π             
Second, it is assumed that the internal volume of the adjustable shoe may be approximated by a cylinder which extends a length equivalent to the stick length of the last. Accordingly, for a given cross-sectional area derived from the girth measured in a particular region, the volume is calculated the equations:
 
             V   =     A   *   L                 V   =         G   2     ⁢   L       4   ⁢   π             
where L is the stick length of the last. Thus, for each girth measurement, a corresponding volume may be calculated for comparisons between lasts. For example, a ball volume, waist volume, and instep volume may all be individually calculated to characterize expandability of the shoe on average or based on a specified region. In some embodiments, the length of the cylinder may be assumed to be less than the stick length of the last, so that the expandability of a particular region of the adjustable shoe may be characterized. According to this embodiment, the expandability of one region of the shoe may be compared with another region of the shoe.
 
       FIGS. 22A to 22B  depict one embodiment of an internal volume  2102  of one embodiment of an adjustable shoe  2100  based on a circumference measurement on a last  2000 . According to the embodiment shown in  FIGS. 22A-22B , it is assumed the internal volume  2102  is approximated by a cylinder  2004  with a circular cross section  2002  corresponding to the measured girth.  FIG. 22A  shows a transverse cross sectional view of the last  2000  in long dashed lines surrounded by the adjustable shoe  2100  in short dashed lines. An overlaid circular cross-section  2002  is shown as an approximate cross-sectional area corresponding to the circumference measured along G 3  to G 4  of the last (e.g., the waist girth). A radius r of the circular cross-section may be derived according to the equations described above from the circumferential measurement of the last in order to compute a cross-sectional area of the last in the region of measurement. As shown in  FIG. 22B  and discussed previously, the internal volume of the adjustable shoe is assumed to be approximately equal to that of a cylinder  2004  extending a length equal to the stick length of the last between S 1  and S 2  (for example, see  FIG. 21A ). Accordingly, the volume of the cylinder may be calculated from the equations described above. After the occupied volume of the last is calculated based on one or more measurement regions for a nominally sized last and one or more larger lasts which expand the shoe, the amount of volume expansion may be determined by comparing the calculated volumes. In particular, a volume expansion ΔV based on a particular circumferential measurement can be calculated by the equation:
 
Δ V=V   max   −V   nom  
 
where V max  is the calculated volume based on the largest last which fits the adjustable shoe and V nom  is the calculated volume based on a nominally sized last which fits the adjustable shoe.
 
       FIGS. 23A-23B  show an alternative embodiment of last testing measurements for an adjustable shoe. In some cases, rather than measuring the overall stick length for calculating an approximate volume of the entire adjustable shoe, it may be desirable to measure a smaller length corresponding to a particular region of the foot to characterize expandability in that specific region. As shown in the bottom plan view of the last  2050  in  FIG. 23A , the waist length is measured along line X 1 -X 2  on the sole of the last. The waist length corresponds to a waist girth which is a circumference measured along the region of line G 3 -G 4 . With these measurements, the same assumptions regarding the volume of the shoe may be made, so that the volume of the waist region is approximated by a cylinder  2054  with a length corresponding to the waist length (i.e., X 1 -X 2 ), as shown in  FIG. 23B . The radius, r, of the cylinder may be derived from the waist girth assumed to be the circumference of a circular cross section. Thus, the volume of the cylinder representative of the waist region internal volume may be calculated as described above, and this volume of the waist region compared between differently sized lasts. Accordingly, the expandability of an adjustable shoe in the waist region or any other suitable region may be characterized using the method described. 
     According to exemplary embodiments described herein, volume expansion of the shoe may be characterized by an expandability coefficient expressed in terms of percentage. The expandability coefficient may be based at least partly on circumferential expansion (i.e., girth expansion) of the adjustable shoe around one or more cross sectional areas of the shoe (for example, see  FIG. 18E ). The expandability coefficient may be suitable to characterize how much additional volume in different regions the adjustable shoe can accommodate for a nominal shoe size (e.g., US size, Mondopoint, UK size, etc.). Following the cylindrical volume assumptions made in the volume calculations described above, the expandability coefficient ε may be determined from the equation: 
             ɛ   =       Δ   ⁢           ⁢   V       V   nom             
where ΔV is the volume expansion derived from circumferential measurements of a nominally sized last and a largest last which fits the adjustable shoe, and V nom  is a calculated volume from a measurement of the nominally sized last. Alternatively expressed, the expandability coefficient ε may be given by the equation:
 
             ɛ   =         G     ma   ⁢           ⁢   x     2       G   nom   2       -   1           
where G max  is a girth (i.e., circumferential) measurement around a transverse region of the largest last which fits in an adjustable shoe and G min  is a girth measurement around the same transverse region of a nominally sized last which fits in an adjustable shoe. According to this embodiment, the expandability coefficient may correspond to a percentage volumetric expansion capability where the transverse region is assumed to be a circle and the volume is a cylinder with a length corresponding to a length of the last (e.g., an overall length or partial length).
 
     In some embodiments, an adjustable shoe may have regions with an expandability coefficient of greater than or equal to 6%, 7%, 8%, 12%, or 15, or any other suitable factor. Correspondingly, the expandability coefficient of certain regions may be less than 20%, 15%, 12%, 8%, or any other suitable factor. Combinations of the above noted ranges are contemplated, such as expandability coefficients between 8% and 12%, 12% and 20%, as well as 7% and 15%. Of course, any suitable expandability coefficient may be employed for a region of an adjustable shoe to provide sufficient volumetric expansion for various portions of a wearer&#39;s foot, as the present disclosure is not so limited. 
     In some cases, it may be desirable to normalize the calculated volumes based on the standard shoe size of the measured adjustable shoe. For example, normalizing for shoe size may allow volume expansion to be predicted for an adjustable shoe at any given shoe size. According to one embodiment, a predicted volume for a shoe size, V a , may be calculated based on a circumferential measurement of a last with the cylindrical assumptions described above by the equations: 
               G   a     =       G   m     *       S   a       S   m                       L   a     =       L   m     *       S   a       S   m                       V   a     =         G   a   2     ⁢     L   a         4   ⁢   π             
where G a  is the predicted girth measurement for a given shoe size, G m  is the circumferential measurement of the measured last, S a  is the predicted shoe size, S m  is the measured shoe size, L a  is the predicted length measurement for a given shoe size, and L m  is the length measurement of the measured last. According to the equations described above, the prediction assumes linear scaling of the length and circumference of the last with nominal shoe size. Thus, the internal volume of a shoe and the amount of volume expansion may be predicted based on a last testing of a single shoe size.
 
     To demonstrate the measurements and calculations described above, last testing was performed on embodiments of an adjustable shoe similar to the embodiments shown in  FIGS. 18A-20B . Differently sized lasts were tested for fit inside of the shoes, and each tested last had measurements taken in the regions corresponding to them marked measurements shown in  FIGS. 21A-21B . Three of the lasts measured have the measurements recorded in Table 1 below. The lasts were tested in a Women&#39;s US size 7 shoe. A nominally sized 7 last (“7”) was tested, as well as a larger sized last (“7+”) and the largest last which fit inside of the shoe (“7++”). Across each last, the sole of the last was held constant to approximate volumetric swelling of the upper regions of the foot. That is, the bottom length, bottom widths, and stick length were held constant across the lasts. As shown in Table 1, girth measurements (i.e., circumferential measurements) around the last in various regions increased from the nominally sized last 7 to the largest last 7++. The girth measurements correspond to circumference measurements following the labeled lines shown in  FIG. 21A . It should also be noted that while three last measurements are described here for simplicity, any suitable number of lasts may be used to test the shoe to determine the largest last measurements which an adjustable shoe may accommodate in one or more regions of the shoe. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Experimental measurements of differently sized lasts being  
               
               
                 accommodated by a shoe according to exemplary embodiments 
               
               
                 described herein (e.g., the shoes shown in any of FIGS. 18A-20B). 
               
               
                 The experimental results demonstrate an ability to expand the shoe 
               
               
                 volumetrically as measured in various regions of the foot of a wearer. 
               
            
           
           
               
               
               
               
            
               
                 Measurement (mm) 
                 7 
                 7+ 
                 7++ 
               
               
                   
               
            
           
           
               
               
               
               
            
               
                 Stick (S1-S2) 
                 247 
                 247 
                 247 
               
               
                 Bottom Length (L1-L2) 
                 247 
                 247 
                 247 
               
               
                 Bottom Width (W1-W2) 
                 79.9 
                 79.9 
                 79.9 
               
               
                 LBP Heel Width (W3-W4) 
                 59.5 
                 59.5 
                 59.5 
               
               
                 Ball Girth (G1-G2) 
                 230 
                 234.76 
                 239.52 
               
               
                 Waist Girth (G3-G4) 
                 232 
                 236.76 
                 241.52 
               
               
                 Instep Girth (G5-G6) 
                 239 
                 243.76 
                 248.52 
               
               
                 Toe Spring (T1-T2) 
                 17 
                 17 
                 17 
               
               
                 Heel Pitch (H1-H2) 
                 22 
                 22 
                 22 
               
               
                 Toe Thickness (T4-T5) 
                 25 
                 26 
                 26.5 
               
               
                   
               
            
           
         
       
     
     After the measurements were taken for each of the lasts, the girth measurements were used to compute approximate internal volumes. The calculations were performed using the equations described above, with the assumption the internal volume of the shoe was represented by a cylinder which extends the stick length of the measured last. The computed approximate radii and volumes derived from the ball girth, waist, girth, and instep girth measurements are shown in Table 2 below. In particular, a ball radius, waist radius, and instep radius were derived from the ball girth, waist girth, and instep girth, respectively. From the ball radius, waist radius, and instep radius the approximate cross-sectional area was computed and multiplied by the length of the last to yield a cylindrical volume for each girth measurement, as described previously. Once each volume was calculated, the volume expansion, ΔV, between the nominally sized last 7 and the largest last 7++ was computed. Additionally the expandability coefficient, ε, for each region derived volume was calculated. According to this particular shoe embodiment, the volume expandability was between 8-9% for each measured region. Of course, as discussed previously, other adjustable shoe embodiments may have expandability coefficients greater than, less than, or equal to those computed here, as the present disclosure is not so limited. 
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Approximate adjustable shoe radii and volumes calculated 
               
               
                 based on the measured volumes for volume expandability of 
               
               
                 a nominal Women&#39;s US size 7 shoe based on the measurements 
               
               
                 taken in Table 1. The volume calculations assume the 
               
               
                 circumference measurement of the last taken at the ball, 
               
               
                 waist, and instep approximates the circumference of a 
               
               
                 circular cross-section of a cylindrical volume which 
               
               
                 extends the overall length of the shoe (i.e., stick length). 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Ball 
                 Ball 
                 Waist 
                 Waist 
                 Instep 
                 Instep 
               
               
                   
                 Radius 
                 Volume 
                 Radius 
                 Volume 
                 Radius 
                 Volume 
               
               
                 Size 
                 (mm) 
                 (cm 2 ) 
                 (mm) 
                 (cm 2 ) 
                 (mm) 
                 (cm 2 ) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                 7 
                 36.6 
                 1039.8 
                 36.9 
                 1057.9 
                 38.0 
                 1122.7 
               
               
                 7+ 
                 37.4 
                 1083.3 
                 37.7 
                 1101.8 
                 38.8 
                 1167.9 
               
               
                 7++ 
                 38.1 
                 1127.6 
                 38.4 
                 1146.6 
                 39.6 
                 1214.0 
               
               
                 ΔV (7++ − 7) 
                 1.5 
                 87.9 
                 1.5 
                 88.6 
                 1.5 
                 91.2 
               
               
                 ε 
                   
                 8.4% 
                   
                 8.4% 
                   
                 8.1% 
               
               
                   
               
            
           
         
       
     
     After the radii and volumes of the adjustable shoe were calculated based on each of the girth measurements based on the cylindrical volume assumption, the volumes were normalized for a nominal Women&#39;s US shoe size. That is, the computed radius for the nominal last 7 and largest last 7++ were converted into predicted radii for other nominal US shoe sizes based on a linear scaling assumption of the circumferential measurements (i.e., ball girth, waist girth, and instep girth) and overall length between sizes. The predicted nominal volumes and maximum expansion volumes (designated by the “+”) are shown for sizes 4 to 15 in Table 3 below. According to the prediction shown in Table 3, the predicted volume expansion scales cubically with the shoe size. 
     
       
         
           
               
             
               
                 TABLE 3 
               
             
            
               
                   
               
               
                 Predicted volume accommodations for nominal Women&#39;s US 
               
               
                 shoe sizes based on the measurements of the 7-7++ lasts 
               
               
                 shown in Table 1. By normalizing the volume accommodation 
               
               
                 measurements and calculations described above for shoe 
               
               
                 size, the volumetric accommodation of the adjustable shoe 
               
               
                 may be predicted across a range of shoe sizes. The “+” 
               
               
                 size marker in the left column indicates a predicted maximum 
               
               
                 volume accommodation based on the measurements of the 7++ 
               
               
                 last of Table 1. Of course, the measurements may be normalized 
               
               
                 and converted for any suitable shoe size, as the present 
               
               
                 disclosure is not so limited. 
               
            
           
           
               
               
               
               
               
               
               
            
               
                   
                 Ball 
                 Ball 
                 Waist 
                 Waist 
                 Instep 
                 Instep 
               
               
                   
                 Radius 
                 Volume 
                 Radius 
                 Volume 
                 Radius 
                 Volume 
               
               
                 Size 
                 (mm) 
                 (cm 2 ) 
                 (mm) 
                 (cm 2 ) 
                 (mm) 
                 (cm 2 ) 
               
               
                   
               
            
           
           
               
               
               
               
               
               
               
            
               
                  4 
                 20.9 
                 194.0 
                 21.1 
                 197.4 
                 21.7 
                 209.5 
               
               
                  4+ 
                 21.8 
                 210.4 
                 22.0 
                 213.9 
                 22.6 
                 226.5 
               
               
                  5 
                 26.1 
                 378.9 
                 26.4 
                 385.5 
                 27.2 
                 409.2 
               
               
                  5+ 
                 27.2 
                 410.9 
                 27.5 
                 417.8 
                 28.3 
                 442.4 
               
               
                  6 
                 31.4 
                 654.8 
                 31.6 
                 666.2 
                 32.6 
                 707.0 
               
               
                  6+ 
                 32.7 
                 710.1 
                 32.9 
                 722.0 
                 33.9 
                 764.5 
               
               
                  7 
                 36.6 
                 1039.8 
                 36.9 
                 1057.9 
                 38.0 
                 1122.7 
               
               
                  7+ 
                 38.1 
                 1127.6 
                 38.4 
                 1146.6 
                 39.6 
                 1214.0 
               
               
                  8 
                 41.8 
                 1552.1 
                 42.2 
                 1579.2 
                 43.5 
                 1675.9 
               
               
                  8+ 
                 43.6 
                 1683.2 
                 43.9 
                 1711.5 
                 45.2 
                 1812.1 
               
               
                  9 
                 47.1 
                 2209.9 
                 47.5 
                 2248.5 
                 48.9 
                 2386.3 
               
               
                  9+ 
                 49.0 
                 2396.6 
                 49.4 
                 2436.8 
                 50.9 
                 2580.1 
               
               
                 10 
                 52.3 
                 3031.4 
                 52.7 
                 3084.4 
                 54.3 
                 3273.3 
               
               
                 10+ 
                 54.5 
                 3287.6 
                 54.9 
                 3342.7 
                 56.5 
                 3539.3 
               
               
                 11 
                 57.5 
                 4034.8 
                 58.0 
                 4105.3 
                 59.8 
                 4356.8 
               
               
                 11+ 
                 59.9 
                 4375.8 
                 60.4 
                 4449.2 
                 62.2 
                 4710.8 
               
               
                 12 
                 62.8 
                 5238.3 
                 63.3 
                 5329.8 
                 65.2 
                 5656.3 
               
               
                 12+ 
                 65.3 
                 5680.9 
                 65.9 
                 5776.2 
                 67.8 
                 6115.9 
               
               
                 13 
                 68.0 
                 6660.1 
                 68.6 
                 6776.4 
                 70.6 
                 7191.5 
               
               
                 13+ 
                 70.8 
                 7222.8 
                 71.4 
                 7343.9 
                 73.5 
                 7775.8 
               
               
                 14 
                 73.2 
                 8318.3 
                 73.8 
                 8463.6 
                 76.1 
                 8982.0 
               
               
                 14+ 
                 76.2 
                 9021.1 
                 76.9 
                 9172.4 
                 79.1 
                 9711.8 
               
               
                 15 
                 78.4 
                 10231.1 
                 79.1 
                 10409.8 
                 81.5 
                 11047.5 
               
               
                 15+ 
                 81.7 
                 11095.6 
                 82.4 
                 11281.7 
                 84.8 
                 11945.1 
               
               
                   
               
            
           
         
       
     
     While the present teachings have been described in conjunction with various embodiments and examples, it is not intended that the present teachings be limited to such embodiments or examples. On the contrary, the present teachings encompass various alternatives, modifications, and equivalents, as will be appreciated by those of skill in the art. Accordingly, the foregoing description and drawings are by way of example only.