Patent Publication Number: US-2022233914-A1

Title: Pelvis training device

Description:
RELATED APPLICATION 
     This application is a PCT application claiming priority from U.S. Provisional Patent Application No. 62/854,359, filed on 30 May 2019. 
     The contents of all of the above applications are incorporated by reference as if fully set forth herein. 
    
    
     FIELD AND BACKGROUND OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to a pelvis and to core muscles training device and methods, and more particularly, but not exclusively, to a pelvis exercise device and method which engage a continuous disruption of a user&#39;s stability being mounted on a movable seat. 
     Background art includes CN Patent No. 202761985 (U) that describes a “utility model discloses a swing bodybuilding chair. 
     The swing bodybuilding chair comprises a seat body and chair legs, wherein the upper ends of the chair legs are fixedly connected into a whole, an elastic device is connected between the lower end of the seat body and the upper ends of the chair legs, and grab handles are respectively arranged at two sides of the upper ends of the chair legs. Compared with the prior art, the swing bodybuilding chair is simple in structure, convenient to use, and low in cost. When the swing bodybuilding chair is used, a user sits on the seat body and holds the grab handles at two sides by hand, by means of the elasticity of a compression spring, the seat is enabled to swing between the left side and the right side through the applied force by the waist and the buttocks, and therefore the effects of effectively exercising the waist and the buttocks are achieved.” 
     DE Patent No. 4325109 (A1) that describes a “sporting appliance, which can be rolled autodynamically by a person from the inside, is used for sporting activity, rehabilitation and popular entertainment. 
     The external meridians 3, reinforced by latitudinal meridians 4, form the spheroidal exterior 1 and, at the same time, gaps 5 for sight and entry. The outside meridians 3 are connected to caps at the head part 6 and bottom 7. A standing platform 8 accepts rotatable foot supports 14. An annular hand-grip 10, a spring 11 and a telescope 12 constitute the force elements 2 in the sporting appliance, by means of which the person executes some of the shifts of central gravity. 
     The standing platform 8 is connected via a pedestal 9 to the bottom 7, via the telescope 12 and spring 11 with spring travel and telescopic travel, and via their axes of rotation 15, which is also the axis of the spring, in a longitudinally adjustable and rotatable manner. 
     The bottom gripping ring 16 can be connected to the exterior 1, for example at the bottom 7, to a number of exterior meridians 3 or to the lower latitudinal meridian 4 and can be used for propulsion and, in combination with the safety belt 13, for braking.” 
     U.S. Pat. No. 5,570,929 (A) that describes “an active dynamic seat has a base, a stiff intermediate piece linked to the base and a seating part linked to the intermediate piece. 
     The seating part is rigidly secured to the intermediate piece and the intermediate piece is mounted in such a way on the base that its central area can tilt in all directions and slide vertically. In addition, one or several restoring devices are arranged on the intermediate piece, in the area below the mounting point on the base, for restoring the tilting movement and at the same time the vertical displacement of the intermediate piece and the seating part.” 
     U.S. Pat. No. 4,099,697 (A) that describes “a stool-like seat for limited mobility of the user with a high action radius comprises a base formed with a ball socket and a post carrying the seating surface and provided with a ball receivable in the socket. 
     The post has a downwardly extending member engaging, within the base, a star-like array of tension springs which resist angular displacement of the post and bias the latter into a normal upright position.” 
     U.S. Pat. No. 5,524,967 (A) that describes “an active dynamic seat has a base, an intermediate piece linked to the base and a seating part linked to the intermediate piece. 
     The seating part is fixed to the intermediate piece and the intermediate piece is linked to the base by a single bearing in a substantially fixed manner in the vertical direction and in a tilting manner in all lateral directions. The tilting movement is limited in all directions by a stop and one or several restoring devices are provided to restore the unloaded intermediate piece to the vertical.” 
     Patent No. 101382413 (B) that describes “a horse riding device without power. 
     The horse riding device without power according to one embodiment of the present invention includes a support (1), an auxiliary tube (44), a vertical tube with a power plate (22), a connection unit (20), a hollow pipe (8), a hollow cylinder (9), a pair of grinding rods (11) facing each other, rollers (10), a connecting plate (18), a shaft (14), a saddle (36) having a pad (41), a spring (25), a pair of hangers (38), a string (39), a footrest (48), and a screw bolt (52).” 
     NL Patent No. 1017456 that describes a “chair or stool comprises at least one support column (2) which at its lower end is fitted on all sides to a support foot (1) and at its upper end is connected to a seat (3). 
     The connection between the support foot and the support column on the one hand and that between the seat and the support column on the other hand are each formed by a combination of a ball hinge (4 a , 4 b ), around which is formed a ring-shaped spring body.” 
     U.S. Patent No. 2013045812 (A) that describes “a platform is provided, which platform is adapted to engage a base through a multiplicity of pulley engaging cables. 
     A first end of each cable is attached to a cam follower assembly located on the base and a second portion of the cable is attached to the platform. A motor driving the multiplicity of cams, cam followers, and cables will move the platform, the platform typically being suspended above the base on the cables or the cables and compression springs.” 
     KR Patent No. 100952310 (B) that describes “an exercising machine for strengthening waist is provided to strengthen leg muscular and the waist and to supply elastic force to a rotary upper plate in up and down motion and twist motion, and to prevent the dispersion of the center of gravity. 
     CONSTITUTION: An exercising machine for strengthening waist comprises: a fixing lower plate(100) which includes a plurality of non-slip stages and in which a cylinder is installed on the upper center of the fixing lower plate; a rotary upper plate(200) which is slid in the cylinder and is installed on the upper side of the fixing lower plate to buffer a load in contacting with the ground; a compressive elastic member(300) which is located on the cylinder upper part of the fixing lower plate and the outer circumference of the load of the rotary upper plate; and a tension elastic member(400) which is transformed when the rotary upper plate is twisted.” 
     U.S. Patent No. 2009318274 (A) that describes “a balance training device is provided having a body mounted on a flexible pedestal connected to a stable base. The pedestal includes a spring or other similar flexible connection. A user sitting on the body will use muscles of their legs and abdomen to maintain balance on the device.” 
     GB 190914900 (A) patent application that describes an “exercising-apparatus; rocking horses. In an amusement device which may also be used for instructing a person how to ride a horse, the seat has a motion similar to that of a restless horse and is put out of action when the person leaves the seat. A spindle b slides in a sleeve f, and the seat which is secured to the upper end of the rod is supported by a spring c. The sleeve is provided near its center with a ball shaped part i, which moves on ball bearings attached to the framework h. When the sleeve is tilted, it is restored to the vertical, by weights j and springs k. 
     A person taking a seat depresses the spindle b until its lower end engages projections e on a track d. When the spindle b and the track d are moved relatively to one another, the spindle seat is tilted to various angles. 
     According to the Provisional Specification, a light weight may be placed on the device to cause it to rock. By this means, a person will be able to learn to mount a horse while in motion.” 
     Additional background art includes DE Patent No. 10000247 (A1); FR Patent No. 2775193 (A1); U.S. Patent No. 2017/319892 (A1); U.S. Patent No. 2006/052222 (A1); U.S. Pat. No. 4,183,579 (A); WO 08034529A2 patent application; U.S. Pat. No. 6,644,742 (B); U.S. Patent No. 2008280741(A); and KR Patent No. 100786976 (B). 
     SUMMARY OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to a pelvis and to core muscles training device and methods, and more particularly, but not exclusively, to a pelvis exercise device and method which engage a continuous disruption of a user&#39;s stability being mounted on a movable seat. 
     The following describe some examples of embodiments of the invention. Other embodiments are within the scope of the description, including embodiments in which only some of the features from one example are used. 
     Other embodiments are within the scope of the description, including examples in which some of the features are selected from two or more examples. 
     Following are some examples of some embodiments of the invention: 
     EXAMPLE 1 
     A pelvis exercising system comprising:
     a movable seat, sized and shaped to support a user by his pelvis;   a vertical supporter which supports said seat above the ground;   a flexible connector mounted between said vertical supporter and said seat;   wherein, said seat comprises a front portion and a rear portion extending upwardly away from a central arch, each of the rear and front portions comprises a length which is long enough to support a front portion and rear portion of the user&#39;s pelvis, while not significantly restricting the abdomen and lower back from bending in relation to a sagittal plane of said seat.   

     EXAMPLE 2 
     A pelvis exercising system according to example 1, wherein said vertical supporter is configured to support said seat above the ground at a height which is at least higher than 60 cm. 
     EXAMPLE 3 
     A pelvis exercising system according to examples 1 or 2, wherein said flexible connector is configured to bend to an angle of between 10 to 120 degrees in relation to a longitudinal axis of said vertical supporter in response to a certain force applied to said seat, wherein said certain force is selected from between 300 to 1200 (N). 
     EXAMPLE 4 
     A pelvis exercising system according to example 1, wherein said flexible connector comprises one or more springs located underneath said seat. 
     EXAMPLE 5 
     A pelvis exercising system according to example 1, wherein the length of said vertical supporter is longer than 60 cm. 
     EXAMPLE 6 
     A pelvis exercising system according to any one of examples 1-5, wherein said front portion comprises a length which is at most 25 cm. 
     EXAMPLE 7 
     A pelvis exercising system according to any one of examples 1-6, wherein said rear portion comprises a length which is at most 25 cm. 
     EXAMPLE 8 
     A pelvis exercising system according to any one of examples 1-7, wherein said front and rear portions are movable in relation to each other 
     EXAMPLE 9 
     A pelvis exercising system according to any one of examples 1-8, wherein said movable seat comprises at least two lateral portions, positioned on both sides of said central arch, wherein each of said lateral portions extends downwardly away from said arch. 
     EXAMPLE 10 
     A pelvis exercising system according to example 9, wherein each of said lateral portions is long enough to support a user&#39;s thigh. 
     EXAMPLE 11 
     A pelvis exercising system according to example 10, wherein said lateral portions are movable in relation to each other. 
     EXAMPLE 12 
     A pelvis exercising system according to any one of examples 1-11, wherein said system comprises a peripheral frame positioned around said movable seat, said frame supports one or more anchors. 
     EXAMPLE 13 
     A pelvis exercising system according to example 12, wherein said user is supported, at least in part, by said frame by one or more tensile elements which are connectable to the body of the user, said one or more tensile elements are further connected to said peripheral frame. 
     EXAMPLE 14 
     A pelvis exercising system according to example 13, wherein said one or more tensile elements comprises a rough surface. 
     EXAMPLE 15 
     A pelvis exercising system according to example 13, wherein said tensile element is connected to said peripheral frame by a connector assembly, wherein said connector assembly is operable to modify a length of at least one edge of said tensile element. 
     EXAMPLE 16 
     A pelvis exercising system according to any one of examples 1-15, wherein said movable seat is operable to incline in relation to the ground along bending of said flexible connector. 
     EXAMPLE 17 
     A pelvis exercising system according to claim 16, wherein said inclination is between 0° to 180°. 
     EXAMPLE 18 
     A pelvis exercising system according to example 17, wherein said inclination of said movable seat is actuated by at least one actuator associated with said seat and with said vertical supporter. 
     EXAMPLE 19 
     A pelvis exercising system according to any one of examples 1-15, wherein said movable seat is operable to rotate about said seat&#39;s longitudinal axis, wherein said rotation is clockwise and/or counterclockwise. 
     EXAMPLE 20 
     A pelvis exercising system according to example 19, wherein said rotation of said movable seat is actuated by at least one actuator associated with said vertical supporter. 
     EXAMPLE 21 
     A pelvis exercising system according to any one of examples 1-20, wherein said system includes one or more inertial sensors associated with said movable seat, said sensors are in data communication with a processing unit for analyzing user&#39;s usage data. 
     EXAMPLE 22 
     A pelvis exercising system according to example 21, wherein said usage data includes inclination and/or rotation of said movable seat. 
     EXAMPLE 23 
     A pelvis exercising system according to example 21, wherein said inertial sensors comprises an accelerometer, a gyroscope, and/or a combination thereof. 
     EXAMPLE 24 
     A pelvis exercising system according to any one of examples 1-20, wherein said system includes one or more pressure sensors associated with said movable seat, said sensors are in data communication with a processing unit for analyzing values which are indicative to deviation of weight which is applied on at least a portion of said seat. 
     EXAMPLE 25 
     A pelvis exercising system according to any one of examples 1-20, wherein said system includes one or more body sensors attached to the body and/or to a garment of the user, said sensors are in data communication with a processing unit for analyzing values of at least one physiological parameter. 
     EXAMPLE 26 
     A pelvis exercising system according to example 25, wherein said physiological parameter includes blood pressure, body temperature, neural activity level and/or a combination thereof. 
     EXAMPLE 27 
     A pelvis exercising system according to examples 1-20, wherein said system includes an image sensor which is in data communication with said processing unit, said image sensor detects the position and/or inclination of the body said user, said image sensor reconstructs an image of the selected part of the body of the user and/or seat by a computerized algorithm. 
     EXAMPLE 28 
     A pelvis exercising system according to any one of examples 21-27, wherein said processing unit controls activation of at least one actuator according to a computerized algorithm embedded therein, said actuator is associated with said seat and/or with said vertical supporter, said actuator is in data communication with said processing unit. 
     EXAMPLE 29 
     A pelvis exercising system according to example 28, wherein said system comprising one or more external devices, said external devices are in data communication with said one or more actuators and control activation thereof. 
     EXAMPLE 30 
     A pelvis exercising system according to any one of examples 1-29, wherein said system comprising a displaying unit for displaying user&#39;s usage parameters, said displaying unit includes a GUI. 
     EXAMPLE 31 
     A pelvis exercising system according to any one of examples 1-29, wherein said system comprising displaying inclination of said seat by a ball, wherein the movement of said ball is coupled to the movement of said seat by a peripheral channel which connects said ball with said seat. 
     EXAMPLE 32 
     A pelvis exercising system according to any one of examples 1-31, wherein said vertical support is interconnected to one or more retrieval springs, said springs rotates said vertical supporter back to a vertical supporter&#39;s resting position, by contracting back to a spring&#39;s resting length, wherein said one or more springs are configured so that there exists a force within the range of 10 to 350 N which, when applied to said seat, causes rotation of vertical said supporter of between 10 to 210 degrees in relation to said vertical supporter resting position. 
     EXAMPLE 33 
     A pelvis exercising method comprising: 
     mounting a user above the ground on a movable seat which is positioned in relation to the ground in a starting position;
         restricting the feet of the user from touching the ground;   supporting the pelvis region and a portion of the thighs of the user by said movable seat;   instructing the user to incline said seat to one or more directions in relation to said starting position; and   instructing the user to rotate said seat to one or more directions in relation to said starting position.       

     EXAMPLE 34 
     A pelvis exercising method according to example 33, wherein said method comprises restricting movement of the pelvis of said user to a location between a front and a rear portions of said seat and allowing bending of said user&#39;s lower abdomen and/or back in relation to a sagittal plane of said user&#39;s body. 
     EXAMPLE 35 
     A pelvis exercising method according to any one of examples 33 to 34 comprising, supporting the body of the user by a peripheral frame, which surrounds said movable seat by one or more tensile element connectable to said frame and to a selected portion of the user&#39;s body. 
     EXAMPLE 36 
     A pelvis exercising method according to any one of examples 33 to 35 comprising, inclining and/or rotating said movable seat to a desired direction, said inclination and/or rotation is by the movements of the user&#39;s pelvis and/or core muscles. 
     EXAMPLE 37 
     A pelvis exercising method according to example 36 comprising inclining and/or rotating said seat by pulling an edge of one or more of said tensile element at a desired pulling direction. 
     EXAMPLE 38 
     A pelvis exercising method according to example 33 comprising collecting one or more usage parameters of said user&#39;s by one or more sensors and transmitting said collected data to one or more processing units. 
     EXAMPLE 39 
     A pelvis exercising method according to example 33 comprising:
     detecting the location of at least a portion of the user&#39;s body and/or at least a portion of said seat by an imager;   reconstructing an image of the detected portion of the user&#39;s body and/or seat by said imager; and transmitting said collected data to one or more processing units.   

     EXAMPLE 40 
     A pelvis exercising method according to any one of examples 38-39 comprising analyzing said received data by said processing unit and displaying said analyzed data to the user. 
     EXAMPLE 41 
     A pelvis exercising method according to any one of examples 38-39 comprising analyzing said received data by said processing unit and moving said seat in relation to the ground by controlling activation of one or more actuators which are controlled by said processing unit. 
     EXAMPLE 42 
     A pelvis exercising method according to example 33, wherein said instructing includes exposing the user to one or more audible and/or visual signals. 
     EXAMPLE 43 
     A pelvis exercising method according to example 33, wherein said instructing includes at least one of: 
     instructing said user to move a portion of his body forward; 
     instructing said user to move a portion of his body backwards; 
     instructing said user to move a portion of his body laterally; and 
     instructing the user to rotate a portion of his body clockwise and/or counterclockwise. 
     EXAMPLE 44 
     A pelvis exercising method according to example 43, wherein said movement includes applying pressure on at least a portion of said seat by activating the user&#39;s pelvis and/or core muscles. 
     EXAMPLE 45 
     A method of traction of one or more joints within a user&#39;s body comprising:
         mounting a user above the ground on a movable seat;   restricting the feet of the user from touching the ground;   supporting the pelvis region and a portion of the thighs of the user by said movable seat at a starting posture; and   modifying the posture of the mounted user in relation to said starting posture by moving said seat.       

     EXAMPLE 46 
     A method according to example 45 comprising supporting at least one side of a selected joint by at least one tensile element and/or by said seat above the ground and applying forces on two sides of said joint, said forces being in different amounts and/or directions. 
     EXAMPLE 47 
     A method according to example 46 comprising pulling said at least one tensile element at a direction away from the user&#39;s body. 
     EXAMPLE 48 
     A pelvis exercising system including a seat, a vertical supporter which supports the seat above the ground, a flexible connector mounted between the vertical supporter and the seat, wherein: the flexible connector enables a swaying movement of the seat, and further including a locking prong configured to optionally lock front-to-back movement of the seat. 
     EXAMPLE 49 
     A pelvis exercising system according to claim 48 wherein said swaying movement of said seat is against resistance to movement from a rest position. 
     EXAMPLE 50 
     A pelvis exercising system according to any one of examples 48-49 wherein the swaying movement of the seat is atop the vertical supporter. 
     EXAMPLE 51 
     A pelvis exercising system according to any one of examples 48-50 wherein the swaying movement of the seat occurs above a halfway height between a floor and the seat. 
     EXAMPLE 52 
     A pelvis exercising system according to any one of examples 48-51 wherein a stiffness of the swaying is adjusted by adjusting a length which the flexible connector surrounds the vertical supporter. 
     EXAMPLE 53 
     A pelvis exercising system according to any one of examples 48-51 wherein a stiffness of the swaying is adjusted by adjusting a length which the vertical supporter surrounds the flexible connector. 
     EXAMPLE 54 
     A pelvis exercising system according to any one of examples 48-53 wherein the flexible connector enables side-to-side swaying of the seat, and the locking prong is configured to optionally lock side-to-side swaying of the seat. 
     EXAMPLE 55 
     A pelvis exercising system according to any one of examples 48-51 wherein the flexible connector enables forward and backward swaying of the seat, and the locking prong is configured to optionally lock forward and backward swaying of the seat. 
     EXAMPLE 56 
     A pelvis exercising system according to any one of examples 48-55 wherein the vertical supporter enables up-and-down movement of the seat. 
     EXAMPLE 57 
     A pelvis exercising system according to any one of examples 48-56 wherein the flexible connector enables up-and-down movement of the seat. 
     EXAMPLE 58 
     A pelvis exercising system according to any one of examples 48-57 wherein the vertical supporter enables clockwise and counter-clockwise rotation of the seat. 
     EXAMPLE 59 
     A pelvis exercising system according to example 58 wherein the clockwise and counter-clockwise rotation of the seat is performed against resistance by at least one spring. 
     EXAMPLE 60 
     A pelvis exercising system according to any one of examples 48-57 and further including a strut for manipulating the locking prong to optionally lock movement of the seat. 
     EXAMPLE 61 
     A pelvis exercising system according to example 60 and further including a back cushion connected to the strut for manipulating the locking prong to optionally lock movement of the seat. 
     EXAMPLE 62 
     A pelvis exercising system according to any one of examples 48-61 wherein the seat is saddle-shaped. 
     EXAMPLE 63 
     A pelvis exercising system according to any one of examples 48-62 wherein, the seat includes a front portion and a rear portion extending upwardly away from a central arch, each of the rear and front portions includes a length which is long enough to support a front portion and rear portion of the user&#39;s pelvis, while not significantly restricting the abdomen and lower back from bending in relation to a sagittal plane of the seat. 
     EXAMPLE 64 
     A method of pausing exercise on a pelvis exercising system, the method including exercising on a pelvis exercising system, and locking degrees of freedom of the system. 
     EXAMPLE 65 
     A method according to example 64 wherein the locking includes locking by a user leaning back, pushing back on a back strut. 
     EXAMPLE 66 
     A method of enabling a user to become accustomed to using a pelvis exercising system, the method including providing a pelvis exercising system, and providing a locking mechanism for a user to lock degrees of freedom of the system. 
     EXAMPLE 67 
     A method according to example 66 wherein the enabling the user to lock degrees of freedom includes enabling the user to lean back, pushing back on a back strut, thereby locking degrees of freedom of the system. 
     EXAMPLE 68 
     A method of locking a wobbly seat, the method including providing a wobbly seat, and providing a locking mechanism for a user to lock degrees of freedom of the wobbly seat. 
     EXAMPLE 69 
     A method according to example 68 wherein the locking includes locking by a user leaning back, thereby locking degrees of freedom of the wobbly seat. 
     EXAMPLE 70 
     A pelvis exercising system including a seat, a base, a flexible connector mounted between the base and the seat, and a sensor positioned to measure movement of the seat relative to the base, wherein the sensor provides measured values of the seat relative to the base to a processor, and the processor controls a device based on the measured values. 
     EXAMPLE 71 
     A pelvis exercising system according to example 70 wherein the device includes a plurality of sensors, positioned to measure each degree of freedom in the movement of the seat relative to the base. 
     EXAMPLE 72 
     A pelvis exercising system according to any one of examples 70-71 wherein the device includes a display, and the controlling the device includes displaying the movement on the display. 
     EXAMPLE 73 
     A pelvis exercising system according to any one of examples 70-72 wherein the device includes a display, and the controlling the device includes controlling position of a cursor on the display. 
     EXAMPLE 74 
     A pelvis exercising system according to any one of examples 70-72 wherein the device includes a display, and the controlling the device includes controlling game play in a game displayed on the display. 
     EXAMPLE 75 
     A pelvis exercising system according to any one of examples 70-72 wherein the device includes a display, and the controlling the device includes performing exercises in an exercise program displayed on the display. 
     Unless otherwise defined, all technical and/or scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention pertains. 
     Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of embodiments of the invention, exemplary methods and/or materials are described below. In case of conflict, the patent specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting. 
     As will be appreciated by one skilled in the art, some embodiments of the present invention may be embodied as a system, method or computer program product. Accordingly, some embodiments of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “module” or “system.” Furthermore, some embodiments of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon. Implementation of the method and/or system of some embodiments of the invention can involve performing and/or completing selected tasks manually, automatically, or a combination thereof. Moreover, according to actual instrumentation and equipment of some embodiments of the method and/or system of the invention, several selected tasks could be implemented by hardware, by software or by firmware and/or by a combination thereof, e.g., using an operating system. 
     For example, hardware for performing selected tasks according to some embodiments of the invention could be implemented as a chip or a circuit. As software, selected tasks according to some embodiments of the invention could be implemented as a plurality of software instructions being executed by a computer using any suitable operating system. In an exemplary embodiment of the invention, one or more tasks according to some exemplary embodiments of method and/or system as described herein are performed by a data processor, such as a computing platform for executing a plurality of instructions. Optionally, the data processor includes a volatile memory for storing instructions and/or data and/or a non-volatile storage, for example, a magnetic hard-disk and/or removable media, for storing instructions and/or data. Optionally, a network connection is provided as well. A display and/or a user input device such as a keyboard or mouse are optionally provided as well. 
     Any combination of one or more computer readable medium(s) may be utilized for some embodiments of the invention. The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device. 
     A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device. 
     Program code embodied on a computer readable medium and/or data used thereby may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing. 
     Computer program code for carrying out operations for some embodiments of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user&#39;s computer, partly on the user&#39;s computer, as a stand-alone software package, partly on the user&#39;s computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user&#39;s computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider). 
     Some embodiments of the present invention may be described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks. 
     The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks. 
     Some of the methods described herein are generally designed only for use by a computer, and may not be feasible or practical for performing purely manually, by a human expert. A human expert who wanted to manually perform similar tasks, such as modifying a user&#39;s body postures, might be expected to use completely different methods, e.g., making use of expert knowledge and/or the pattern recognition capabilities of the human brain, which would be vastly more efficient than manually going through the steps of the methods described herein. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Some embodiments of the invention are herein described, by way of example only, with reference to the accompanying drawings and images. With specific reference now to the drawings and images in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of embodiments of the invention. In this regard, the description taken with the drawings makes apparent to those skilled in the art how embodiments of the invention may be practiced. 
       In the drawings: 
         FIG. 1A  shows a schematic illustration of a pelvis training system, according to some embodiments of the invention; 
         FIG. 1B  shows a schematic illustration of a user mounted on the movable seat of a pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 1C  shows a schematic illustration of an exemplary movable seat with schematic illustration of one or more sensors mounted to or integral within a movable seat, according to some embodiments of the invention; 
         FIG. 2A-C  shows a schematic illustration of a user mounted at a “starting” posture on a movable seat while being supported by one or more tensile elements, according to some embodiments of the invention; 
         FIG. 2D-E  shows a schematic illustration of an exemplary tensile element (e.g., straps) connection means to a peripheral frame, according to some embodiments of the invention; 
         FIG. 3A  shows a movable seat mounted on an exemplary rotating vertical supporter connected by an exemplary one or more retrieval springs to a base, according to some embodiments of the invention; 
         FIG. 3B  shows a schematic illustration of a retrieval springs, disposed inside an exemplary housing and mounted on an upper section of a vertical supporter, according to some embodiments of the invention; 
         FIG. 3C  shows a schematic illustration of an exemplary telescopic vertical supporter deployed at an un-nested configuration, according to some embodiments of the invention; 
         FIG. 4A  shows a schematic illustration of an exemplary design of a saddled-shaped movable seat, according to some embodiments of the invention; 
         FIG. 4B  shows a front schematic illustration of an exemplary design of a saddled-shaped movable seat, according to some embodiments of the invention; 
         FIG. 5A  shows a front schematic illustration of a body-seat contact area marked on an exemplary front portion of a movable seat, according to some embodiments of the invention; 
         FIGS. 5B-D  show a schematic representation of contact area of regions of the user&#39;s pelvis with a movable seat, according to some embodiments of the invention; 
         FIG. 6 (I-V) shows a perspective views of a user mounted on an exemplary design of an exemplary movable seat, according to some embodiments of the invention; 
         FIG. 7  shows a flowchart of a pelvis training method using a pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 8A  shows a perspective front view of a user using an exemplary pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 8B  shows a perspective view of a user using an exemplary pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 9 (I-XII) shows an exemplary postures of a pelvis training method using the pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 10  shows a perspective views of an exemplary design of a movable seat, according to some embodiments of the invention; 
         FIG. 11 (I-IV) shows a schematic illustration of a seat-movements indicative circumferential track, according to some embodiments of the invention; 
         FIG. 12  shows a schematic representation of the location of user&#39;s body center of gravity, according to some embodiments of the invention; 
         FIG. 13  shows an exemplary graphic user interface (GUI) of acquired data of a user&#39;s motion and/or pressure parameters which is detected during the use of a pelvic training device (PTD), according to some embodiments of the invention; 
         FIG. 14 (I-IV) shows a perspective views of a user mounted in an exemplary design of an exemplary segmented movable seat, according to some embodiments of the invention; 
         FIG. 15 (I-II) shows a schematic illustration of an exemplary segmented movable seat in a folded and in an un-folded configurations, according to some embodiments of the invention; 
         FIG. 16  shows a perspective view of an exemplary segmented movable seat, according to some embodiments of the invention; 
         FIG. 17  shows a perspective top view of an exemplary segmented movable seat, according to some embodiments of the invention; 
         FIG. 18  shows a perspective view of an exemplary segmented movable seat mounted on an exemplary vertical supporter, according to some embodiments of the invention; 
         FIG. 19  shows a perspective view of portions of the segmented movable seat, according to some embodiments of the invention; 
         FIGS. 20A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention; 
         FIGS. 21A-C  show schematic illustrations of the pelvis training system shown by  FIGS. 20A-20C ; 
         FIGS. 22A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention; 
         FIGS. 23A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention; 
         FIGS. 24A-E  show schematic illustrations of a pelvis training system, according to some embodiments of the invention; 
         FIG. 25  shows a schematic flow chart illustration of a method of pausing exercise on a pelvis exercising system according to some embodiments of the invention; 
         FIG. 26  shows a schematic flow chart illustration of a method of enabling a user to become accustomed to using a pelvis exercising system according to some embodiments of the invention; 
         FIG. 27  shows a schematic flow chart illustration of a method of locking a wobbly seat according to some embodiments of the invention; 
         FIGS. 28A-D  show a schematic illustration of locking mechanisms for locking a wobbly seat according to some embodiments of the invention; and 
         FIG. 29  shows a schematic illustration of controlling movement using data from sensors in a pelvis exercising system according to some embodiments of the invention. 
     
    
    
     DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION 
     The present invention, in some embodiments thereof, relates to a pelvis and to core muscles training device and methods, and more particularly, but not exclusively, to a pelvis exercise device and method which engage a continuous disruption of a user&#39;s stability being mounted on a movable seat. 
     Overview 
     An aspect of some embodiments of the invention relates to causing a user to use his pelvis and/or his core muscles for balancing his body while being supported by a movable seat. Optionally, the seat has a saddle shape. Optionally, the seat is sized and shaped to support the user&#39;s pelvis region while the user straddling the seat. 
     In some embodiments, the movable seat may be adjusted, for example with regard to size and its shape to change the engagement of the seat with the user. Optionally, such change is used to change the location and/or force of contact between the seat and the user&#39;s body, for example according to the size of the user&#39;s body and/or according to a therapeutic or a training program. 
     In some embodiments, the movement of the seat includes inclination and/or rotation. Optionally, the movement is caused by the user which applies force using his pelvis, thighs and/or core muscles on a selected portion of the seat. Optionally or alternatively, the movement is caused or otherwise meditated by one or more actuators positioned externally or integral with portions of the pelvic training device (PTD). 
     In some embodiments of the invention, the seat inclines and/or rotates without significant translational movement. For example, the saddle point of the seat moves less than 30 cm, less than 20 cm or intermediate amounts during an inclination of 60 degrees and/or during a rotation of 90 degrees. Optionally, a hinge point for the seat is located within 30 cm, 20 cm, 10 cm or intermediate distances of the saddle point of the seat. 
     Optionally or alternatively, the seat inclines and/or rotates along with an additional translational movement component. For example, the saddle point of the seat may move laterally to a distance between 0 and 30 cm, optionally, to a distance between 0 and 20 cm, optionally, to a distance between 0 and 10 cm or intermediate distances in relation to a resting position thereof. 
     In some embodiments, the movable seat has a low profile, which is defined by a low frontal and rear walls and optionally selected to avoid interfering with flexing of the user&#39;s trunk. Optionally, the highest edge of the seat (in relation to the ground) does not exceed the height of the pelvis bones, such that the abdomen and lower back of the mounted user are free to be bend in relation to a sagittal and/or in relation to a frontal plane of the user&#39;s body. 
     In some embodiments, the user is supported by the seat and his feet are not supported by or rested on any surface. In some embodiments, the user is supported above the ground at a height which is between 60 cm to 140 cm. 
     In some embodiments, the user is supported at a height which is between, for example, 60 to 80 cm, 80 to 90 cm, 90 to 100 cm, 100 to 110 cm, 110 to 120 cm, 120 to 130 cm, 130 to 140 cm, and/or 100 to 150 cm and/or intermediate or greater heights above the ground. 
     In some embodiments of the invention, restriction of contact between feet and the ground is by supporting the seat on a vertical supporter, which extends from a base or from the floor and having a length which is longer than the length of the user&#39;s legs. 
     In some embodiments, the vertical supporter supports the seat above the ground at a height which is at least higher than 60 cm. 
     A potential advantage of restricting the user&#39;s feet from touching the ground is preventing user posture control by applying force to the ground (e.g., as in regular, standing, posture). Such preventing may force the user to use mainly his thighs, pelvis and/or other core muscles to stabilize himself while being seated on the seat. 
     In some embodiments, the user is supported at various body inclinations in relation to the ground, which are followed by inclination of the movable seat. Optionally, the inclinations include a lateral tilt (e.g., to the left or to the right) and/or a frontal/rear tilt. 
     In some embodiments, the seat is supported at an inclined position using a flexible connector, for example a spring, optionally positioned underneath the movable seat and which interconnects the seat and the vertical support. Optionally, the spring is configured to bend in any direction in relation to the ground. 
     In some embodiments, rotation of the movable seat includes a clockwise and/or a counterclockwise rotation. Optionally, the rotation is by rotation of the vertical supporter, which optionally may rotate about its longitudinal axis. Optionally, rotation of the seat is by rotation of the flexible connector (e.g., a spring and/or a joint) and/or by a combined rotation of the flexible connector and the vertical supporter. 
     In some embodiments, the movements are preformed according to a training and/or according to a therapeutic protocol. 
     An aspect of some embodiments of the invention relates to exercising a user&#39;s skeletal and/or core muscles, by supporting his body above the ground by one or more support means. In some embodiments, the support means are positioned at one or more locations around the user&#39;s body. In some embodiments, the support means include a movable seat which is positioned underneath the user and additional one or more tensile elements (e.g., straps). 
     In some embodiments, one or more straps are mounted on (e.g., tied around) one or more portions of the user&#39;s body and are further connected to one or more peripheral anchoring point(s). Optionally, the anchoring points are located at different locations on a peripheral frame which surrounds the mounted user. In some embodiments of the invention, one or more straps are held by the user. 
     In some embodiments, the user may voluntary incline his body to a desired inclination angle by pulling a desired strap in a desired pulling direction. Optionally or alternatively, the body of the user may be inclined involuntary, e.g., following movements of components in the pelvic training device (PTD). In some embodiments of the invention, movement is due to seat movement. Optionally or additionally, movement is due to a change in length or elasticity of a tensile element (e.g., shortened by a motorized actuator or allowed to extend by releasing a blocking actuator). In some embodiments, inclination of the user&#39;s body may be beneficial for training the user and/or strengthening at least some muscles of his body. 
     In some embodiments, the mounted user may be rotated following rotation of a vertical supporter and may be pulled to one or more directions, following pulling of a selected strap, such that the user is enforced to stabilize himself on the movable seat at various movement patterns. 
     In some embodiments, supporting a user by the additional tensile elements may be advantageous in allowing a large inclination angles and/or along fast rotational movement which may enable training different muscles at different training difficulties. Optionally or alternatively, supporting a user by the additional tensile elements may be advantageous in allowing inclining at precise inclination angles and/or along slow rotational movement which may enable training different muscles at different training difficulties. 
     An aspect of some embodiments of the invention relates to exercising a user&#39;s skeletal and/or core muscles using real-time guidance. Optionally, the real time guidance includes directing the user to perform selected movements, for example by inclining his body while sitting on a movable seat. In some embodiments, the real-time guidance comprises acquiring body motion data by one or more sensors. Optionally, the sensors detect usage data from the user&#39;s body. Optionally, usage data includes movement patterns such as inclinations and/or rotations of the movable seat. Optionally or alternatively, usage data includes pressure applied by portions of the user&#39;s body on the seat. Optionally, usage data is detected by sensing motions of components of the pelvic training device (PTD). In some embodiments, the detected data is analyzed. Optionally, the data is displayed. 
     In some embodiments, the acquired data includes movement parameters (applied by the mounted user) such as directions and/or distances (such as centimeters or millimeters) and/or velocities (e.g. centimeters per second) and/or inclination angles (e.g. from 0 to 180 degrees) detected by motion sensors. Optionally, the acquired data includes pressure parameters (applied by the mounted user) such as pressure intensity, frequency by one or more pressure sensors. Optionally, the acquired data includes physiological parameters such as blood pressure, body temperature, and/or neural activity level. 
     Optionally, the acquired data is detected by an image sensor (e.g., a camera), which monitors the motions of the user. 
     In some embodiments, the acquired data is transmitted to a processing unit, which processes the acquired data and transmits signals to a displaying unit, such analysis may be performed by an embedded control software. 
     In some embodiments, the data (e.g., acquired, processed and/or guidance) is displayed by a graphical user interface (GUI) on a screen. Optionally or alternatively, data is transmitted to the user by a visual and/or by an audial and/or by a vibrational signaling, and/or by combination thereof. 
     An aspect of some embodiments of the invention relates to traction of one or more joints within the user&#39;s body. Optionally, traction is provided by modifying the posture of the mounted user when sitting on a movable seat. In some embodiments of the invention, the traction includes modifying the relative orientation and/or the gap between corresponding bones within one or more joints of the user&#39;s body in relation to each other. Optionally, such modification includes coupling one or more straps to one or more portions of the user&#39;s body. Optionally, the body of the user is pulled to one or more directions. 
     In some embodiments of the invention, traction is provided by the forces on two sides of a joint being in different amounts and or directions, for example, gravity acting in one direction and a strap in another. Optionally, the method of support of the user (not by his feet) allows part of the weight of the user to apply such a force. 
     Optionally, pulling is initiated and/or controlled by the user which pulls a strap to a desired direction, and move his body towards the pulling direction. Optionally or alternatively, pulling is by one or more actuators (such actuators may be motorized), which are connected to the straps that may pull the user by the straps to a desired directions. 
     Potential benefits of joint traction includes promoting blood circulation within the joints, rehabilitation of defective joints and/or improving neural activity within the joints and/or in tissues near the joint (e.g., within 10 cm of the joint). 
     In some embodiments, the pelvic training device (PTD) and/or system described herein is used for therapeutic applications such as physiotherapy and/or rehabilitation and/or bone fractures and/or joints injuries and/or ligaments/tendon injuries. 
     In some embodiments, the pelvic training device (PTD) and/or system described herein is used for non-therapeutic applications such sport and/or fitness exercises. 
     In some embodiments, the pelvic training device (PTD) and/or system described herein is used for cosmetic applications which involve re-shaping of one or more areas of the user&#39;s body. 
     An aspect of some embodiments of the invention relates to a seat which is configured to move side-to-side and/or front-to-back and/or rotate, relative to a base of the seat. 
     Such movement potentially causes a user to exercise abdominal muscles and/or core muscles to find a stable seating position. 
     In some embodiments degrees of freedom of movement of the seat relative to the base of the seat include one or more of: 
     Side-to-side swaying; 
     Forward-and-backward swaying; 
     Side-to-side or clockwise-and-counterclockwise rotation; and 
     Up-and-down-bouncing. 
     In some embodiments, the movement in any one or more of the degrees of movement is optionally against resistance, for example movement against resistance of a spring. 
     Such movement potentially causes a user to balance on the potentially shifting seat, and find a healthy seating position. 
     In some embodiments, the seat can optionally bounce up-and-down, potentially adding to the exercise aspect. 
     In some embodiments, the seat can be locked from movement relative to the base of the seat, providing stability when needed. 
     In some embodiments, the seat can be locked by the user leaning back against a back cushion. 
     In some embodiments, controls are provided to enable each one of the degrees of freedom of movement described above. 
     In some embodiments, a separate control is provided to enable locking and unlocking each one of the degrees of freedom of movement described above separately. 
     In some embodiments, a control is provided to optionally enable locking and unlocking more than one of the degrees of freedom of movement described above together. 
     In some embodiments, one or more sensors are provided to enable measuring movement at one or more of the degrees of freedom of movement described above. 
     In some embodiments the seat enables a user to sit with the pelvic joints straight, or bent at an angle. 
     An aspect of some embodiments of the invention relates to a seat which is configured to move side-to-side and/or front-to-back relative to a base of the seat. 
     In some embodiments, the seat performs a swaying or wobbling movement atop a stiff support. The swaying movement optionally occurs nearer the seat bottom than the floor. In some embodiments the movement is a movement of a seat swaying atop a post, rather than a seat rigidly connected to a post which sways at its bottom, near the floor. 
     In some embodiments, a flexible connector or spring is attached to a seat, extending down, and connected to a vertical support or post. In some embodiments, the flexible connector surrounds a top portion of the vertical support. The portion of the flexible connector surrounding the top portion of the vertical support cannot sway much, if at all. A portion of the flexible connector extending above the top portion of the vertical support can sway flexibly. 
     In some embodiments, an amount by which the flexible connector extends above the top portion of the vertical support can be adjusted. The adjustment potentially adjust a stiffness of the swaying, and/or potentially adjusts a range of motion of the swaying, as expressed in degrees from a central position, or as expressed in centimeters from the central position. 
     An aspect of some embodiments of the invention relates to using sensors to measure movement of the seat along one or more of the degrees of freedom which the seat can move, and using values thus measured in a computer application. 
     Re-enumerating the degrees of freedom listed above, the degrees of freedom of movement of a seat according to some embodiments include one or more of: 
     Side-to-side; 
     Forward-and-backward; 
     Side-to-side or clockwise-and-counterclockwise rotation; and 
     Up-and-down. 
     It is noted that 4 degrees of freedom are listed above. 
     In some embodiments, the sensors send values measured for movement along one or more of the degrees of freedom to a processor, and the processor optionally uses one or more of the values. 
     Some uses for the sensor values include: 
     a) Controlling movement of a cursor on a display. 
     b) Controlling movement of a game control on a display, potentially enabling playing a game. 
     It is noted that the above-mentioned four degrees of freedom potentially enable controlling a display in one, two, three or four dimensions (by way of a non-limiting example including time as a dimension). 
     By way of a non-limiting example, playing Pong, which requires controlling movement of a paddle along one dimension, can be done by associating side-to-side movement, or forward and backward movement, to movement of a paddle used in the game. 
     By way of a non-limiting example, controlling a kayak simulation game, for example by rotating the seat to control the direction of the simulated kayak, and leaning sideways to control a weight of a simulated paddler in the simulated kayak 
     By way of another non-limiting example, controlling a snow ski simulation game, for example by rotating the seat to control the direction of the simulated skis; leaning sideways to control a sideways leaning of a simulated skier on the simulated skis; leaning forward or backward to control forward and backward lean, and moving, or bouncing, up and down on the seat to simulate jumping or skiing over moguls. 
     c) Controlling movement of a device movement in at least one, two, three or four degrees of freedom. 
     d) Tracking a user&#39;s movement on the seat. Such tracking can sense changes in a user&#39;s posture. In some embodiments, a display displays one or more measures of the user&#39;s posture to the user. In some embodiments, the user is additionally displayed desired values, and asked to perform exercise on the seat so as to reach the desired values. 
     Exemplary Embodiments 
     Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not necessarily limited in its application to the details of construction and the arrangement of the components and/or methods set forth in the following description and/or illustrated in the drawings and/or the Examples. The invention is capable of other embodiments or of being practiced or carried out in various ways. 
     The following exemplary embodiments describe, inter alia, a pelvic training device (PTD) comprising a movable seat which is sized and shaped to house a pelvis region of a mounted user. In some embodiments, the seat is elevated above the ground to a height which is at least longer than the length of the mounted user&#39;s leg. 
     In some embodiments, the device defines a sagittal plane and a frontal plane. Optionally, the seat can incline in a sagittal and/or in a frontal direction. Optionally, the seat may rotate about its longitudinal axis, for example by rotation of a vertical supporter which supports the seat and which is further operable to rotate clockwise and counterclockwise in relation to the seat&#39;s longitudinal axis. In some embodiments, the seat is connected to the vertical supporter by a spring. Optionally, the spring is bendable at any direction. Optionally, the spring may twist about its longitudinal axis (which is parallel to the seat&#39;s longitudinal axis). 
     In some embodiments, movements are transmitted from the mounted user&#39;s body, through the seat to the vertical supporter and to the bendable spring. For example, when the user voluntary and/or involuntary applies pressure or moves his body towards a certain direction. 
     Optionally, movements are transmitted through the vertical supporter and through the spring to the seat, for example following rotation of the vertical supporter and/or following bending/twirling of the spring. 
     In some embodiments, because a contact between the mounted user&#39;s feet and the ground is restricted, the user is forced to stabilize himself on the seat by his pelvis and/or by his core/skeletal muscles. In addition, and while said seat moves, said self-stabilization is required at various inclinations of the user&#39;s body in relation to the ground which further leads to pelvis and core/skeletal muscles training. 
     In some embodiments, the user may use one or more tensile elements, e.g., supporting straps, which are connectable to his body, which are further connected to external anchoring locations around his body, to stabilize himself on the seat. Such supporting straps may enable inclinations of the user at a wide range of angles while not slipping off the seat (comparing to an inclinations without such additional straps), which may help to train the user at a wide range of movements as part of a training/therapeutic protocol. 
     Referring to the drawings,  FIGS. 1A-B  show a schematic front illustration of a pelvic training device (PTD)  100 , according to some embodiments of the invention. The system comprises an interface (e.g., a seat  101 ) on which a user  111  ( FIG. 1B ) is mounted. Optionally, the interface supports a portion of the user&#39;s body such as the area between the lower abdomen and the bottom of the pelvis. Optionally, the interface supports the user also by his thighs. 
     Optionally, seat  101  is mounted by a flexible connector  102 , for example a spring (or by more than one spring) on a vertical supporter  103 . Optionally, spring  102  supports movement of seat  101  relative to other parts of system or relative to the ground. Optionally, spring  102  connects seat  101  to a vertical supporter  103 . 
     In some embodiments, pelvic training device (PTD)  100  includes one or more anchoring locations  112  (e.g., barbs and/or hooks), optionally surrounding seat  101 . In some embodiments, anchors  112  are mounted to or integral with a peripheral ring  114 . In some embodiments, device (PTD)  100  includes one or more straps  113  connectable to anchoring locations  112  which are further connectable to the user&#39;s body. 
     In some embodiments, pelvic training device (PTD) is made for adult users. Optionally, each part of the device can bear a weight of, for example, 0-350 kg, 0-150 kg, 150-200 kg, 200-300 kg and 300-350 kg static or dynamic, without breaking and/or plastically deforming. 
     In some embodiments, each part of pelvic training device (PTD)  100  can bear loads for example of between 0 to 3500 N, 0-1500 N, 1500-2000 N, 2000-3000 N and 3000-3500 N without breaking and/or plastically deforming. 
     Movable Seat: 
     In some embodiments, seat  101  is saddle shaped. Optionally the seat comprises one or more convex portions (e.g., portions  440  and  450  at  FIG. 4A ), optionally positioned at a front portion of seat  101  (in front of the mounted user) and at a rear portion of seat  101  (behind the mounted user). In some embodiments, seat  101  includes one or more concave portions (e.g., portions  460  at  FIG. 4A ). In some embodiments, the concaved portions are positioned between the front portion and the rear portions, in vicinity of the thighs of the mounted user  111  (e.g., lateral portions). 
     In some embodiments, seat  101  includes a central arch (e.g., portion  410  at  FIG. 4A ) positioned between the convex portions and the concave portions. In some embodiments, the central arch comprises a saddle point. In some embodiments, each of the convex portions extends upwardly away from the arch. In some embodiments, each of the concave portions extends downwardly away from the arch. In some embodiments, the height of each of the convex portions, which is defined as the height above the central arch, does not exceed the height of the user&#39;s ilia bones. 
     In some embodiments, the distance between the front and rear convex portions is long enough to house the pelvis of the user. Optionally, the distance is at most 40 cm. optionally or alternatively, the distance is at most 35 cm, 30 cm. 
     Optionally, the distance is between 20 cm to 40 cm. optionally, the distance is between 20 cm to 35 cm. optionally, the distance is between 20 cm to 30 cm. 
     In some embodiments, user  111  is mounted on a top portion of the seat (which faces upwards) with his legs spread apart from each other. 
     In some embodiments, the height of seat  101  above the ground is defined by the length of vertical supporter  103 , said seat  101  is mounted on a distal end (in relation to the ground) of the vertical supporter  103 . 
     In some embodiments of the invention, user  111  (shown for example, at  FIG. 1B ) is forced to stabilize himself on seat  101  by activating the muscles of his pelvis and thighs and/or his inner core-muscles; this activation may be advantageous in training these body areas. 
     In some embodiments, seat  101  has a fixed size and/or shape. Optionally or alternatively, as shown for example at  FIG. 15 , seat  1500  may comprise one or more portions (for example one or more frontal  1501  portions, one or more rear  1501  portions, and one or more lateral  1502  portions). In some embodiments, the portions of the seat may move in relation to each other, thereby to adjust the size and/or shape of the seat. Potential benefits of adjusting the location and/or extent of contact area between the seat and the user&#39;s is forcing the user to apply modified amount of force on parts of the seat to maintain his stability. 
     In some embodiments, flexible connector (e.g., spring)  102  may be bent in relation to the ground and/or in relation to vertical supporter  103  following force which is applied on seat  101 . In some embodiments, the inclination of spring  102  may be at any positive or negative inclination angle in relation to a sagittal/frontal plane of pelvic training device (PTD)  100  and/or in relation to a sagittal/frontal plane of the user&#39;s body. In some embodiments, inclination is between 0 to 180 degrees. In some embodiments, inclination to about 180 degrees may be advantageous in forcing the user to activate additional muscles as part of the wide range movement. In some embodiments, such a wide range of movement is by supporting portions of his body (e.g., legs and/or hands) to additional straps. 
     Optionally, said inclination is between 0 to 150 degrees. Optionally or alternatively, said inclination is between 0 to 90 degrees. In some embodiments, inclination between 0 to 90 degrees may be advantageous in training the user to perform small range movements (e.g., movements that requires pelvis movements within 10, 15, 20 degrees while being inclined) to increase precise and control of his muscle. Optionally or alternatively, the inclination is between 0 to 75 degrees. Optionally or alternatively, the inclination is between 0 to 50 degrees. In some embodiments, inclination is between 0 to 25 degrees, or at any angle between 0 to 180 degrees. 
     Here are definitions of coordinate systems, which may be used to explain some embodiments of the invention: 
     In some embodiments, pelvic training device (PTD)  100  is divided into a frontal part (which supports the front portion of the user&#39;s pelvis), lateral parts (which supports the pelvis and thighs of the user) and a rear part (which supports the rear portion of the user&#39;s pelvis). 
     Optionally, pelvic training device (PTD)  100  is divided by a frontal plane, which divides pelvic training device (PTD) 100 to the frontal and the rear parts. Optionally, pelvic training device (PTD)  100  is divided by a sagittal plane that divides pelvic training device (PTD) 100 to the lateral (left and right) parts. 
     In some embodiments, the frontal and the sagittal planes are perpendicular in relation to each other. 
     In some embodiments, said frontal and sagittal plans divide the user&#39;s body at the same manner, namely the sagittal plane divides the user&#39;s body to a left and right parts and the frontal plane divides the user&#39;s body to a frontal part and to a rear part. 
     Movement of an Exemplary Seat  101 : 
     In some embodiments, movements of seat  101  include inclination and/or rotation or combination of such movements. Optionally, movements are initiated by user  111 , or by activation of one or more actuators  117  (for example by an electric motor). In some embodiments, the actuators may be mounted to or integral with one or more parts of pelvic training device (PTD)  100 , for example, with vertical supporter  103 , peripheral frame  114 , spring  102  and/or with seat  101 . In some embodiments, the actuators are operable to cause movements of one or more parts of pelvic training device (PTD)  100  in relation to the rest of device  100 . In some embodiments, actuators  117  are powered by one or more of electricity and/or pneumatic and/or hydraulic pressure. 
     In some embodiments, seat  101  may rotate following rotation of vertical supporter  103  which may rotate about a bearing, for example bearing  104 . Optionally, vertical supporter  103  may rotate following activation of actuator  117 . 
     Optionally, bearing  104  is positioned at a lower portion of vertical supporter  103 , and is further connected to base  115  of pelvic training device (PTD). Optionally, bearing  104  is positioned at an upper portion of vertical supporter  103 , and is further coupled to spring  102  or directly to seat  101  itself (as illustrated for example at  FIG. 3B ). 
     In some embodiments, actuator  117  is controlled by a control signal, provided, for example, by a controller (e.g., control unit)  118 . 
     In some embodiments, the control signal is a wireless signal, which is optionally transmitted from a remote control unit (e.g., units  121 , and/or  122 , and/or  123 , shown for example, at  FIG. 1B ). In some embodiments, remote control unit may include a mobile device  122  or remote control  121  having an embedded control software and a communication circuitry, which may transmit a wireless signal according to the embedded control software therein. Optionally, signal is transmitted from an external server, such as  123  and delivered to actuator  117  (and/or controller  118 ) via, for example, an Internet, with a last step optionally being wireless, for example, using WiFi or Bluetooth standards. 
     In some embodiments of the invention, control software may be used to control one or more movement of seat  101 , rotation of vertical supporter  103 , elongation and/or shortening of straps  113  and/or bending of spring  102 . 
     In some embodiments, the control software is optionally software which runs on a user&#39;s personal computer and/or on a user&#39;s mobile device, such as a smart phone or tablet. 
     In some embodiments, connector  102  comprises two or more segments having a degree of movement freedom in relation to each other. In some embodiments, the joint is positioned underneath seat  101 , wherein at least one end of the joint is connected to seat  101  and at least a second side of the joint is connected to vertical supporter  103 . In some embodiments, connector  102  couples seat  101  with vertical supporter  103 . In some embodiments, joint  102  is a multidirectional joint, operable to allow movement at multiple axial (e.g., X, Y and Z) directions and in relation to the sagittal and/or to the frontal planes of pelvic training device (PTD)  100 . 
     In some embodiments, connector  102  is configured to bear a weight of an adult user without undergo a plastic deformation. 
     Vertical Supporter: 
     In some embodiments, vertical supporter  103  is mounted perpendicular to a base  115 . In some embodiments, seat  101  is mounted directly on vertical supporter  103 . 
     Rigidness: In some embodiments, vertical supporter  103  is formed of a rigid material, such as a polymer and/or metal or combination thereof. Optionally, vertical supporter  103  is rigid enough to bear a weight of an adult user without bending or breaking. For example, vertical supporter  103  may bend up to 10 degrees without breaking at a static weight of up to 350 kg. 
     Length: In some embodiments, vertical supporter  103  has a length which is longer than the length of an average adult leg (e.g., between 60 to 140 cm). 
     In some embodiments, vertical supporter  103  supports seat  101  above the ground at a height which is at least higher than 60 cm. Optionally or alternatively, at a height which is at least higher than 70 cm. Optionally or alternatively, at a height which is at least higher than 80 cm. Optionally or alternatively, at a height which is at least higher than 90 cm. Optionally or alternatively, at a height which is at least higher than 100 cm. 
     In some embodiments, vertical supporter  103  may have a length between 30 cm to 140 cm, for example, between 30 cm and 100 cm and/or between 100 cm and 140 or at any intermediate length between them or a greater or smaller length. 
     Optionally or alternatively, the length of vertical supporter  103  is adjustable. For example, vertical supporter  103  may be segmented into one or more pieces assembled as a telescopic assembly (shown for example at  FIG. 3C ). Optionally, the assembly includes a nested configuration wherein at least one segments is nested in another segment. Optionally, the assembly includes an un-nested configuration, wherein none of the segments are nested. 
     Vertical Supporter Rotation: 
     In some embodiments, one or more retrieval springs  105  extends between vertical supporter  103  and a portion of base  115 . Optionally, by the retrieval springs  105  vertical supporter  103  is maintained at and/or returned to a resting position thereof following rotation thereof. 
     Optionally, two retrieval springs  105  are connected perpendicularly to vertical supporter  103  at opposite sides of vertical supporter  103  and pull vertical supporter  103  in an opposite directions, with a stable resting position defined thereby. 
     Base: 
     In some embodiments, base  115  affixes pelvic training device (PTD) 100 to a fixed location on the ground, for example by one or more anchors such as screws and/or barbs attached to a portion thereof which faces the ground. 
     In some embodiments, base  115  comprises one or more pairs of supporting frames  128  which are aligned horizontally to the ground. Optionally, each of supporting frames  128  has a rectangular shape. In some embodiments, each frame  128  comprises a pairs of long parallel shafts  122  which are positioned perpendicular to vertical supporter  103  and parallel to the ground. Optionally, shaft  122  which faces the ground comprises a friction enhancement means at the ground facing side thereof, for example a rubber and/or a sticky element and/or one or more anchoring barbs, by which stability of the base of the pelvic training device (PTD) on the ground is maintained. 
     Optionally, base  115  has a characterizing weight and a center of mass. Optionally or alternatively, the characterizing weight is heavier than the combined static or dynamic weights of the mounted user, vertical supporter  103  and seat  101 , thereby supports the pelvic training device (PTD) perpendicular to the ground. In some embodiments, the characterizing weight is high enough for maintaining vertical supporter  103  perpendicular to the ground, or at most to be inclined ±5° in relation to the ground, for example during rocking of the device when being used. 
     In some embodiments, the characterizing weight restricts the position of a center of mass of the combination of mass of pelvic training device (PTD)  100  and the mass of the mounted user to a location closer to base  115  than to the mounted user. Such restriction may be advantageous in stabilizing the overall device and mounted user, as the user sits on movable seat  101  with his body inclined. In some embodiments, base  115  is designed for supporting a mass of pelvic training device (PTD)  100  and of mounted user  111  having a maximum weight of up to 350 kg static or dynamic. 
     Peripheral Frame: 
     In some embodiments, pelvic training device (PTD)  100  comprises frame  114  which surrounds seat  101 . 
     In some embodiments, peripheral frame  114  supports one or more anchors  112 , by which one or more straps  113  are connectable to frame  114 . 
     In some embodiments, anchor  112  may comprises a groove and/or a peg and/or a ring and/or a hook through/by which strap  113  is connected. 
     In some embodiments, frame  114  is made of a single shaft. Optionally, the shaft is bendable to form a closed shape. Optionally, the user may incline his body freely to any direction within the perimeter of the frame without contacting the frame. 
     In some embodiments, frame  114  is comprised of more than one segments. In some embodiments, the segments are connected to each other. Optionally or alternatively, the segments are not connected to each other. 
     Optionally, frame  114  is positioned parallel to the frontal plane of pelvic training device (PTD). Optionally, the frame is perpendicular to the sagittal plane of the pelvic training device (PTD). Optionally, frame  114  is positioned perpendicular to the frontal plane of pelvic training device (PTD). Optionally, the frame is parallel to the sagittal plane of the pelvic training device (PTD). Optionally, frame  114  is positioned at an angle in relation to the frontal and/or sagittal plane of pelvic training device (PTD). 
     Optionally or alternatively, frame  114  is rotatable in relation to the frontal and/or sagittal plane of pelvic training device (PTD). 
     In some embodiments, frame  114  is rigid. Optionally, frame  114  comprises one or more rigid materials therein, for example metals, and/or metal alloys and/or polymeric materials and/or combination thereof. 
     Optionally, frame  114  is strong enough to bear the weight of an adult user. For example by one or more anchors by which the user is supported, without bending or breaking. Optionally, frame  114  may bear a weight of up to 350 Kg without breaking. 
     In some embodiments, frame  114  is bendable. For example, frame  114  may bend up to 10 degrees without breaking at a weight of up to 350 kg. In some embodiments, frame  114  may be attached to a wall, for example by one or more screws-type fasteners and/or may be welded to a wall. 
     In some embodiments, at least a portion of peripheral frame  114  is connected to a stable position, optionally to base  115  by a connector  116 . Optionally, connector  116  comprises a screw-type fastener. 
     Strap (Tensile Element): 
     In some embodiments, pelvic training device (PTD)  100  includes one or more straps  113  connectable to frame  114 . Optionally, straps  113  hung from one or more locations at frame  114 . In some embodiments of the invention, straps  113  are connectable to one or more locations of the user&#39;s body. 
     In some embodiments, strap  113  is strong enough to bear the weight of an adult user without tear. In some embodiments, straps  113  has an adjustable length. Optionally or alternatively, straps  113  are non-elastic. Optionally or alternatively, straps  113  are pliable. In some embodiments, straps  113  are made of a soft material. In some embodiments, straps  113  may be coupled around a portion of user&#39;s  111  body. For example, strap  113  may be wrapped around the body of user  111 . Optionally, straps  113  may be tied to the hands or to other parts of the user&#39;s body. 
     In some embodiments, connection of straps  113  to a selected portion of user&#39;s  111  body may be advantageous for assisting user  111  to stabilize himself when mounted of movable seat  101 . For example, when user  111  is inclined at an angle in relation to vertical supporter  103 , user  111  may hold a selected portion of strap  113  and lean his body while remain stable on seat  101 . In some embodiments, user  111  may lean his body while being supported by one or more straps  113  to an angle which is larger than 90° in relation to its longitudinal axis (frontal and/or rear and/or lateral or at any inclination direction there between). 
     Optionally, the user may exercise at various inclinations by activating muscles at different inclinations at various strength levels. 
     Sensors: 
     In some embodiments, pelvic training device (PTD)  100  comprises one or more sensors. In some embodiments, the sensors collect data about a user&#39;s usage data of the device. In some embodiments, said usage data includes movement parameters of one or more elements of the pelvic training device (PTD). In some embodiments, usage data includes pressure parameters, for example amount of pressure which is applied by one or more portions of the user&#39;s body on one or more portions of pelvic training device (PTD)  100 . In some embodiments, the usage data includes a combination of pressure parameters and user&#39;s movement parameters. 
     In some embodiments, the movement parameters are collected by inertial sensors such as a gyroscope and/or accelerometer or by a combination thereof. 
     In some embodiments, movement parameters includes rotational speed and/or rotation direction of elements of the pelvic training device (PTD). 
     Optionally, movement parameters includes inclinations of elements of the pelvic training device (PTD) in relation to each other or in relation to the ground. In some embodiments, movement parameters are collected by one or more magnetometers which are integral with the seat. 
     In some embodiments, said usage data includes movement of portions of the mounted user&#39;s body in space. In some embodiments, said usage data includes movement of portions of the mounted user&#39;s body in relation to portions of pelvic training device (PTD)  100  for example in relation to the seat  101  or to vertical supporter  103 ). In some embodiments, such movement includes rotational speed and/or rotation direction. 
     In some embodiments, said usage data includes pressure applied on one or more portions of seat  101  and/or on spring  102  and/or on vertical supporter  103 . 
     In some embodiments, the sensor(s) are connectable to the body of the mounted user, for example to his head, and/or to his pelvis and/or to his truck or limbs. 
     Optionally, usage data is collected by sensors which are mounted on or integral with components of the pelvic training device (PTD). For example by sensors which are coupled to the vertical supporter  103 , to seat  101  and/or to spring  102 . 
     In some embodiments, each of said sensors comprises an ID, which is assigned for example for each sensor by a processing unit. In some embodiments, the acquired data is analyzed by a computerized algorithm which is stored in control/processing unit  118 . Optionally, processing unit  118  is in data communication with each of the sensors. Optionally, the acquired data is analyzed. In some embodiments, said analysis includes translation of data which is collected by the sensors for identification of usage parameters. Optionally, the data is displayed. 
     In some embodiments, the processing unit  118  is optionally a user&#39;s personal computer and/or a user&#39;s mobile device, such as a smart phone or tablet. 
     Body Sensor: 
     In some embodiments, pelvic training device (PTD)  100  comprises one or more body sensors  124  configured to detect physiological parameters, such as body temperature, blood pressure and/or neural activity. Optionally, the body sensors are applied on the user&#39;s body (e.g., directly on the skin and/or garment). Optionally, a collected data of at least one physiological parameters may be transmitted to control unit, e.g. control unit  118 . Optionally, a collected data of at least one physiological parameters may be transmitted through seat  101  (e.g., by sensors at the surface of the seat which are in contact with the user&#39;s body and/or garment). 
     In some embodiments, the collected physiological parameters may serve as an input for processing unit  118  for example for controlling movements of one or more parts of pelvic training device (PTD)  100 . In some embodiments, the input (e.g., which may be transmitted to the processing unit in a characteristic form, such as signal pattern intensity) may use to control movement (e.g., by activating actuators) of one or more components of pelvic training device (PTD)  100 . Optionally, movement (e.g., activation/deactivation) of at least a portion of pelvic training device (PTD)  100 , e.g. seat  101  and/or vertical supporter  103  may be controlled by signals which are transmitted from control unit  118  according to a control algorithm which is stored in processing unit  118 . 
     Optionally, the received signal may be converted by processing unit  118  to activation signal of one or more actuators 
     In some embodiments, body sensor  124  comprises an electroencephalography sensor  124 . Optionally, the sensor is attached to the head of user  111 . 
     Optionally, electroencephalography sensor  124  detects neural activity of the user&#39;s brain, and converts such activity to an electric signal which is transmitted to control unit  118 . 
     In some embodiments, pelvic training device (PTD)  100  comprises one or more image sensors. In some embodiments, the user&#39;s usage parameters are detected by image sensor  126  which is configured to for obtaining one or more visual reference points, for example of one or more portions of the mounted user&#39;s body and of seat  101 . Optionally, image sensor  126  is configured for obtaining visual reference points including of the location of the user&#39;s body and the location of peripheral frame  114  and/or the location of vertical supporter  103 . 
     In some embodiments, seat  101  houses one type of sensors (e.g., inertial or pressure or magnetic sensors). Optionally or alternatively, seat  101  houses several types of sensors, e.g., a motion sensor and/or a pressure sensor which may be incorporated in different parts of seat  101 . 
     Optionally, such sensors arranged at a surface of seat  101  at multiple points. Optionally, the sensors arranged as a “sensing surface”, for example sensing surface  125  as exemplified at  FIG. 1C , by which the pressure applied by the pelvis and/or thighs of the user  111  on seat  101  is detected. In some embodiments, said sensors within sensing surface  125  may be positioned adjacent to each other. In some embodiments, sensors are positioned at the left and/or at the right sides and/or at the frontal and/or at the rear sides of seat  101 . In some embodiments, for example, the pressure sensors are sensitive enough detect changes in weight (e.g., changes of between 1 gram to 100 Kg) which is applied by an average user&#39;s body weight. 
     Optionally, the amount of detected pressure and/or movement velocity/direction is displayed to the user for example on a screen. For example, on a screen of a remote device such as a screen of a mobile phone (e.g., element  122  at  FIG. 1B ). Optionally, data is transmitted to a displaying unit which may be incorporated with the pelvic training device (PTD), for example to a screen, as shown for example at  FIGS. 12-13 . In some embodiments of the invention, the screen is in data communication with one or more sensors which are mounted to or integral with the pelvic training device (PTD) and/or with the user&#39;s body (e.g., elements  125  at  FIG. 1C  and element  124  at  FIG. 1B  respectively). Optionally, the screen is in data communication with at least one processing unit (e.g., element  118  at  FIG. 1A ). Optionally or alternatively, the screen is in data communication with an imager  126  (shown for example, at  FIG. 1B ). 
     In some embodiments, a signal is transmitted from processing unit  118  which is in data communication with a speaker. Optionally, the speaker produces audio signals according to electric signals received from processing unit  118 , said audio signals are detectable, by user  111 . 
     In some embodiments, signals received from processing unit  118  by the speaker may include usage instructions to the user, for example according to movements of the seat and/or pressure which is applied on the seat and may be translated into a characterizing sound. 
     Displaying of usage parameters may be advantageous in providing a real time feedback and/or guidance to user  111  during the usage of pelvic training device (PTD)  100 . 
     Another advantage of displaying the data is that the displayed data may be useful for diagnostics of the usage manner of the pelvic training device (PTD) by the user and deduction of the occurrence of certain physical condition(s) of user  111 , for example by an embedded algorithm, by which usage patterns are translated to body malfunctions. Optionally or alternatively, the acquired data may be used to define a training program. 
     In some embodiments, usage data, such as inclination of seat  101  in relation to vertical supporter  103  is collected for example by magnetometer. 
     Optionally, the magnetometer includes a first piece and a second piece. In some embodiments, the first piece includes a magnetic sensor and the second piece includes a magnetic body. In some embodiments, the magnetic sensor and the magnetic body are magnetically coupled. In some embodiments, the magnetic sensor is positioned in proximity or integral with seat  101  (as shown for example at  FIG. 1C , element  125 ). Optionally, the magnetic body is positioned on parts of the pelvic training device (PTD) which may move in relation to seat  101 , such as vertical supporter  103 . Optionally, the magnetic body may be positioned on the user&#39;s body. 
     In some embodiments, as the position of the magnetic sensor and the magnetic body in relation to each other alters, so as the signal which is transmitted by the magnetometer alters. Optionally, such signal alteration may be indicative to the movements of the user&#39;s body. 
     Data Analysis: 
     In some embodiments, signals received form the sensors (e.g., signals received by the accelerometer and/or by the gyroscope and/or by the magnetic sensor) are compared to each other and analyzed according to an embedded algorithm, which is stored in the processing unit, which translates the received signals and produces an output which represents the user&#39;s usage parameters. 
     In some embodiments, analysis of the usage parameters includes translation of the signals received from the inertial sensors into movement directions in all three axis (X, Y and Z). 
     In some embodiments, the signals from the inertial sensors are translated according to the detected movement velocities. In some embodiments, the analysis includes translation of the signals received from the pressure sensors according to the location of the pressure sensor, for example on the seat. In some embodiments, after being translated, the analysis includes generating a translation table or function mapping of movement and/acceleration and/or angular rotation measurements to seat  101 , thereby to extrapolate information regarding the posture and/or inclination of the seat and the mounted users thereon. 
     In some embodiments, the signals which are received from sensors which are integral with the seat itself, e.g., pressure and/or inertial sensors are translated by a translation table for mapping pressure which is applied on portions of the seat itself or movements of portions thereof. 
     In some embodiments, the analysis includes sorting the signals received from sensors which are applied on the body of the user, to extrapolate information regarding some physical condition of the user (e.g., his body temperature and/or his neural activity). 
     In some embodiments, the analyzed data is used to define a therapeutic or a training protocol, for example by creating a digital file which may be stored at a memory of the processing unit. Optionally, the digital file is downloaded from processing unit  118  to an external memory unit. In some embodiments of the invention, the digital file may include a series of usage instructions (movements and/or pressures) of seat  101 . In some embodiments of the invention, the digital file may include usage instructions such as pulling of straps  113  at a certain manner and or positioning of the body in a certain orientation. In some embodiments, the digital file may assist a caregiver and/or a trainer to set a training/therapeutic program. 
     Image Sensor: 
     In some embodiments, the position and/or inclination of the body of a user and/or seat  101  and/or selected parts of the user&#39;s body are detected by an image sensor, for example by image sensor  126 . Optionally, image sensor  126  is located at a location far enough from user  111 to capture a selected body portion within its field of view. In some embodiments, the imager is in data communication with processing unit  118  to which the imager may send signals. Optionally, by an embedded algorithm, which is stored in the processing unit, the received signals are analyzed. Optionally, the analysis includes translation (reconstruction) of the signals to location of the user&#39;s body in space. Optionally, the location of the user&#39;s body in relation to pelvic training device (PTD)  100  (e.g., vertical supporter  103 , frame  114 ) is defined. In some embodiments, the positions and/or inclinations and/or motions of the user&#39;s body are reconstructed by a computerized algorithm embedded in image sensor  126  or in a control unit which is in data communication with image sensor  126 . In some embodiments, the processing unit  118  is optionally a user&#39;s personal computer and/or a user&#39;s mobile device, such as a smart phone or tablet. 
     In some embodiments, reconstruction is performed by analyzing the location of at least a portion of the user&#39;s body. Optionally or alternatively, reconstruction is based on analyzing the location of at least a portion of the pelvic training device (PTD). 
     Data Storage 
     In some embodiments, the data received from image sensor(s) and/or from inertial sensor(s) and/or from a pressure sensor(s) and/or from one or more sensors which are attached to the user&#39;s body, is stored at external database, e.g., external cloud  123  and/or at external processing unit  122 . Optionally, the stored data is uploaded to a user&#39;s virtual “personal electronic directory”. In some embodiments, such data storage may serve a caregiver of the user or the user himself, to assess his progress and usage parameters such as usage duration and/or movement parameters and motion patterns. 
     Optionally, cloud  123  includes a processor with at least one table and/or with at least one algorithm. Optionally, the stored algorithm includes a computer readable instructions configured to modify at least one usage parameter. Optionally, the usage parameter may include inclination and/or rotation of seat  101 . Optionally, the parameter may include seat rotation of vertical supporter  103 . 
     Connectivity to External Devices: 
     In some embodiments, one or more parts of the system such as seat  101  and/or vertical supporter  103  includes a communication circuitry. Optionally, the communication circuitry may be in data communication with one or more actuators operable to control movement of pelvic training device (PTD) parts in a desired manner. In some embodiments of the invention, data and/or commands may be sent between one or more communication circuitries (by wires or wireless). Optionally, data and/or commands are transmitted/received from/to a remote processing unit(s). Optionally or alternatively, commands are transmitted/received from/to processing unit  118 . Optionally or alternatively, signal are transmitted/received from a mobile phone  122  and/or from a cloud or form an external server  123 . 
     In some embodiments, data is transmitted between actuation means, which move components of the pelvic training device (PTD) by wires extending between said components. 
     In some embodiments, user may press on a control button to transmit a control signal to activate a desired actuator. For example, a control button located at remote controller  121  or at mobile phone  122 . Optionally or alternatively, the control signal is transmitted automatically, according to a control software embedded in remote controller  121  or mobile phone  122  or personal computer or tablet. 
     In another example, controller  118  transmits a control signal to actuate movement of strap  113 . For example, to a motorized strap spindle actuator  119  which pulls strap  113  to wound or to un-wound the strap around the spindle. 
       FIG. 2A  shows a schematic illustration of a user  111  mounted at an upright posture, namely a “starting/native position” on a seat  101 . The figure shows an exemplary two straps  113  wound around the user&#39;s body, by which the user is secured above the ground to peripheral ring  114 . 
     In some embodiments, the location of the pelvis of the user is restricted for example due to the shape of seat  101  which comprises a rear and a front elevated protrusions which blocks slipping off of the user forward or backwards from the seat. In some embodiments, the pelvis is restricted for example to a desired height above the ground. Optionally, the height is defined by the height of seat  101 . Optionally, the height is defined by the length of straps  113  by which the user  111  may hang/support himself from frame  114 . 
     Starting/Native Position 
     In some embodiments, at the starting position, the longitudinal axis of seat  101  is aligned parallel with the longitudinal axis of the user&#39;s body and both are perpendicular to the ground. 
     Optionally, user  111  can incline his body to any desired direction, thereby to incline seat  101  as well. As user  111  inclines, the location of his center of gravity typically changes. In some embodiments, the displacement of the location of the user&#39;s center of gravity relative to its location at the starting position following different body inclinations and postures involves activation of different muscles groups. Optionally, such activation may be advantageous in training different muscles in the thighs and/or in the pelvis of the user. 
     Lateral Tilt: 
     In some embodiments, user  111  may incline a portion of his body either to the left side or to the right side. During lateral inclination, the user is typically required to apply pressure by his inner thighs and pelvis on the lateral portions of seat  101  by bringing his thighs towards the seat to grip the seat, in order to maintain his stability. 
     In some embodiments, seat  101  may be inclined both laterally and/or to the front/rear. 
     Frontal and Rear Tilt: 
     In some embodiments, user  111  may incline the seat in relation to the ground, for example by movements of his pelvis to a frontal and/or in to a rear inclinations. 
     In some embodiments, user  111  is secured by strap  113  to peripheral frame  114 . Optionally, as the user tilts his body and/or as seat  101  inclines in relation to the starting position, the movement may be restricted according to the location and/or length of strap  113  in relation to the movement direction. 
     In some embodiments, strap  113  may be fastened to the body of the user firmly. Optionally, the strap may be fastened loosely, thereby restricting the movement at a lager inclination angles. 
     Optionally, strap  113  may be elastic and can be stretched when pulled. In some embodiments, a stretchable strap may be advantages by causing gradual pulling resistance, which may allow different training difficulties. 
     Straps&#39; Connectivity with the User&#39;s Body 
     Referring now to  FIG. 2B , the figure shows an exemplary strap  113  connected to the user&#39;s body according to some embodiments of the invention. 
     Strap Grasping by the User: 
     In some embodiments of the invention, user  111  holds strap  113  by his hands and pulls his body to a desired direction. Optionally, strap  113  is long enough to be wound around a selected portion of user&#39;s  111  body, for example around his waist. Optionally, around his wrist, optionally, around his ankle. 
     In some embodiments, strap  113  is anchored to a selected one or more points at peripheral frame  114 . 
     Referring now to  FIG. 2C  that shows a schematic illustration of a surface area of an exemplary a strap  113 . In some embodiments, the strap may include a smooth surface area (for example at a side that doesn&#39;t faces the user&#39;s body). Optionally or alternatively, the strap may include a rough (e.g., bumpy) surface over at least a portion thereof. Optionally, the bumpy surface includes for example a series of knobs. 
     Optionally, the strap may include both smooth and bumpy surface areas at the same side. A potential advantage of a bumpy surface may include increasing of the friction as the strap encounters the body of the user such that an enhanced grip of the body may be achieved. 
     Strap&#39;s Connection with the Peripheral Frame: 
     Referring now to  FIGS. 2D-E  that show a schematic illustration of exemplary strap  113  connected to peripheral frame  114  through an exemplary anchor  112 . In some embodiments, anchor  112  is in a form of a hook. 
     In some embodiments, strap  113  is connectable to (e.g., threaded through) hook  112  which is optionally affixed to peripheral frame  114 . Optionally, one or more hooks  112  are connected and/or integral with frame  114 . Optionally, said one or more hooks are positioned at different locations along frame  114 . In some embodiments, as straps  113  being connected to different hooks  112 , the user&#39;s body may be supported from various directions. In some embodiments, supporting the user from various directions may be advantageous in training his body muscles at various difficulty levels. 
       FIG. 2E  shows an exemplary connector assembly  1120  of strap  113  to frame  114 , for example in a form of a spindle  1122 . In some embodiments, assembly  1120  divides strap  113  into at least two edges. 
     In some embodiments, assembly  1120  includes a shaft  1124  portion by which the assembly is connected to frame  114 . 
     In some embodiments, spindle  1122  rotates freely about shaft  1124 . In some embodiments, strap  113  is wrapped around spindle  1122 . Optionally, by pulling a first edge  1135  of strap  113 , optionally by the user, the length of a portion of strap  113  which is un-wrapped around spindle  1122  becomes longer and a second edge  1137  of strap  113  becomes shorter, and to the opposite, according to the straps pulling direction. 
     In some embodiments, spindle  1122  rotates upon activation of an actuator, such as an electric motor. In some embodiments, the actuator may be activated following a control signal(e.g., an electric signal, pneumatic signal and/or mechanical signal) received for example from control unit  118  as shown for example at  FIG. 1B . 
     Referring now to  FIG. 3A  that shows a schematic illustration of the rotation directions of an exemplary vertical supporter  103  and the movement directions of an exemplary seat  101 , according to some embodiments of the invention. 
     Movement Directions of the Movable Seat 
     In some embodiments, movable seat  101  is inclined in relation to the ground at an inclination angle which is between 0° to 180°, wherein 0° inclination is when the longitudinal axis of seat  101  is perpendicular to the ground and 90° inclination is when the longitudinal axis is parallel to the ground. Optionally or alternatively, the inclination angle is between 0° to 150°. Optionally or alternatively, the inclination angle is between 0° to 90°. Optionally or alternatively, the inclination angle is between 0° to 45°. 
     In some embodiments, inclination of seat  101  is determined, at least in part, by the amount of load (N) which is applied by the user on the seat. Optionally, the user may apply pressure on seat  101  towards a desired direction, for example by his pelvis. Optionally, the location of the user&#39;s center of gravity changes the inclination of the seat. In some embodiments, the location of the center of gravity is modified by the posture of the user while being mounted on the set, which causes inclination of the seat. 
     In some embodiments, flexible connector (e.g., spring)  102  which supports seat  101  may oppose the inclination of seat. In some embodiments, flexible connector  102  may resist inclination of seat  101 . Optionally or alternatively, spring  102  may resist inclination of seat  101 . In some embodiments, the flexible connector can be as flexible as the spring. 
     Optionally, flexible connector (e.g., spring)  102  is operable to bend in relation to the ground and/or in relation to the longitudinal axis of vertical supporter  103  following load (N) which is applied on the spring. 
     In some embodiments, flexible connector (e.g., spring)  102  is operable to bend to an angle between 10 to 120 degrees in relation to the longitudinal axis of the vertical supporter upon a load of between 300 to 1200 (N) which may be applied on said seat. 
     In some embodiments, flexible connector (e.g., spring)  102  bends to an angle between 10 to 120 degrees upon a load of between 300 to 400 (N), 400 to 500 (N), 500 to 600 (N), 600 to 700 (N), 700 to 800 (N), 800 to 900 (N), 900 to 1000 (N), 1000 to 1200 (N) and/or 1200 to 1300 (N) and/or 1300 to 1400 (N) and/or 1400 to 1500 (N) and/or 1500 to 1600 (N) and/or intermediate or greater loads. 
     In some embodiments of the invention, the user is required to apply an increasing amount of force (N) to a desired inclination direction in order to increase the bending angle of flexible connector (e.g., spring)  102 . 
     Optionally, bending angle of spring  102  is proportional to the amount of force (N) which is applied on seat  101 . 
     In some embodiments, resistance of flexible connector  102  may be advantageous in strengthening the user&#39;s core and/or pelvis muscles due to the force that the user needs to apply in order to overcome the resistance of the flexible connector to initiate movement (and/or to rotate) to a certain direction. 
     Optionally, the resistance of flexible connector  102  may be uniform in all directions (e.g., to the front/rear and laterally). Optionally or alternatively, the resistance of flexible connector  102  may be non-uniform, for example, the flexible connector may bent more easily in relation to the sagittal plane then in relation to the frontal plane of the device (or of the user&#39;s body). Optionally or alternatively, the flexible connector may bent more easily in relation to the frontal plane then in relation to the sagittal plane of the device (or of the user&#39;s body). 
     In some embodiments, the resistance of flexible connector is adjustable. Optionally, the adjustment may include increasing or reducing the resistance of the connector by installing a desired amount of springs. In some embodiments, adjustment may include increasing or reducing the number of springs included in flexible connector  102 , for example flexible connector  102  may include any number of springs between 1 and 20, between 1 and 10, between 1 and 5, and between 1 and 3 springs. 
     Movement Directions of the Vertical Supporter 
     In some embodiments, vertical supporter  103  rotates about its longitudinal axis. In some embodiments, seat  101  rotates along rotation of vertical supporter  103 . 
     In some embodiments, the rotation is clockwise or counterclockwise. 
     In some embodiments, vertical supporter  103  is mounted on base  115  by a pivotal bearing which is further connected to a first end of at least two retrieval springs  105 . In some embodiments, each of retrieval spring  105  is connected by its second end to base  115 . In some embodiments, each of the retrieval springs  105  may extend following rotation of vertical supporter  103 . In some embodiments, each of the retrieval springs  105  may resist rotation of vertical supporter  103  according to a spring&#39;s constant, for example by contracting back to the spring&#39;s resting length (namely an un-stretched length). 
     In some embodiments, rotation of vertical supporter  103  is modified by the amount of force (N) which is applied by the user, (e.g., by his pelvis) on seat  101  towards a desired rotation direction. In some embodiments, as the user&#39;s pushes the seat to a desired direction, rotation of vertical supporter  103  in relation to a resting position which is connected to seat  101 , for example by flexible connector  102  occurs. 
     In some embodiments, rotation of seat  101  and vertical supporter  103  is modified for example by the location the user&#39;s center of gravity, said location may move according to the posture of the user while being mounted on seat  101 . 
     In some embodiments, rotation of seat  101  and vertical supporter  103  is modified both by the amount of force (N) which is applied by the user on the seat and by the user&#39;s center of gravity. 
     In some embodiments of the invention, force of  10  to  350  N causes rotation of vertical supporter  103  of between  10  to 210 degrees clockwise and/or counterclockwise in relation to the resting position. In some embodiments, force of 10 to 350 N causes rotation of vertical supporter  103  of between for example 10 to 40 degrees, 40 to 10 degrees, 100 to 140 degrees, 140 to 180 degrees, 180 to 210 degrees and/or intermediate or greater rotation angels. 
     In some embodiments, extension of retrieval spring  105  between 5 and 25 cm requires force which is between 10N to 350N. Optionally, extension of retrieval spring  105  between 5 to 25 cm requires force which is between 50N to 100N, 100 to 150N, 150 to 200N, 200 to 250N, 250 to 300N and/or 300 to 350N and/or intermediate or greater loads. 
     Optionally, the second end of retrieval spring  105  is connected for example via a carabiner  1051 , as shown for example at  FIG. 3A ( i ). Optionally or alternatively, retrieval spring  105  is connected to base  115  via a threaded screw  1053 , as shown for example at  FIG. 3A ( ii ). Optionally, the tension of retrieval spring  105  can be modified, for example by threading screw  1053  deeper into the wall of base  115 . 
     In some embodiments, pivoting of vertical supporter  103  about its longitudinal axis is by a retrieval spring  302 , which is mounted at a top end of vertical supporter  103 , as shown for example, at  FIG. 3B . Optionally, retrieval spring  302  connects seat  101  with vertical supporter  103 . In some embodiments, retrieval spring  302  is disposed inside a housing (II) which is positioned on a top end of vertical supporter  103 . According to some embodiments, rotation of vertical supporter  103 , for example by the user, stretches retrieval spring  302 . Optionally, retrieval spring  302  opposes rotation of vertical supporter  103  and restores vertical supporter to its starting position. Optionally or alternatively, retrieval spring  302  opposes rotation of seat  101  and restores seat  101  to its starting position. 
     Referring now to  FIG. 4A  that shows a perspective view of a seat  101  and to  FIG. 4B  that shows a front view of a seat  101 , according to some embodiments of the invention. 
     In some embodiments, seat  101  comprises a front and rear portions having a low profile. In some embodiments, the front and rear portions supports the pelvis region and restricts its location to a region between the frontal and rear portions. Optionally, the frontal and rear portions do not block movement of the lower abdomen and movement of the lower back in relation to pelvic training device&#39;s (PTD)  100  sagittal plane. 
     Optionally, seat  101  comprises two lateral portions  460  (for example, left and right walls shown for example, at  FIG. 4A ), which support the user&#39;s left and right thighs respectively. 
     In some embodiments, support is by restricting the movement of the pelvis (forward or backwards) to the location within a region between the frontal and rear portions of the seat. Optionally or alternatively, support is by restricting the location of a sagittal axis (e.g., shown as dashed line at  FIG. 1B ) of the user&#39;s pelvis to a region between a right edge ( 402 ) and a left edge ( 404 ) of seat  101  as shown for example at  FIG. 4B . 
     In some embodiments, the location of the pelvis within the region between the frontal and rear portions and within the region between left  404  and right  402  edges of seat  101  can be modified. 
     Optionally, by modifying the distance between the frontal and rear portions of seat  101 . 
     Optionally or alternatively, by modifying the shape of seat  101 , for example by inclining parts of seat  101  (e.g., front and/or rear portions) in relation to each other. 
     Exemplary Seat Design 
     According to some exemplary embodiments, seat  101  comprises an upper face and a lower face. In some embodiments, a transversal length of seat  101  is defined as the distance between the internal edge of the front portion and the internal edge of the rear portion of the seat (shown in  FIG. 4A  as a transversal dashed black arrow). 
     In some embodiments, the upper face of seat  101  faces the body of the user, for example the pelvis region and/or thighs. 
     In some embodiments, the top portion of seat  101  comprises a curvature which is shaped and sized to conform to an anatomical curvature of a user&#39;s buttock and/or pelvis region. 
     According to some embodiments, seat  101  comprises a central arch  410  extending in the medial region of seat  101  between the front and rear portions. In some embodiments, central arch  410  connects lateral left wall and lateral right wall  460  of seat  101  (as shown for example, at  FIG. 4A ). Optionally, central arch  410  has a width (shown for example, at  FIG. 4B ) which is in a range of 1-25 cm, for example between 1-12 cm, 12-25 cm, 5-15 cm, 7-20 cm or any intermediate, smaller or larger widths. In some embodiments, the width of central arch  410  defines the extent of straddle between the user&#39;s legs when sitting on seat  101  and may be advantageous in modifying the extent of traction for example of the user&#39;s hips joint and/or the traction between vertebrates within the user&#39;s spinal. 
     In some embodiments, as shown for example at  FIG. 4B , the lateral portions (e.g. left wall  408  and the right wall  406 ) are long enough to support the user&#39;s thighs. Optionally, each of the walls comprises a maximal length, defined by the distance between the central arch  410  and the lowest edge of each wall. In some embodiments, the length is at most the length of an adult&#39;s thigh. In some embodiments, the length is between 5-40 cm. optionally, the length is between 5-30 cm. optionally or alternatively, the length is between 5-20 cm, or any intermediate, smaller or larger value. 
     Each of the right wall  406  and the left wall  408  has an external surface which encounters the user&#39;s thigh. Optionally, the distance between the external surfaces can be modified, for example by inclining the right wall  406  and the left wall  408  in relation to each other. 
     Optionally, inclination between the walls is by an actuator  412  which is operable to move at least one of the walls in relation to the other. 
     In some embodiments, modification of the inclination between the lateral walls may be advantageous in modifying the extent of traction for example of the user&#39;s hips joint. 
     In some embodiments, the front portion and rear portion of seat  101  protrude in a direction away from central arch  410 . 
     Optionally, the distance between at least a portion of front portion  440  and at least a portion of rear portion  450  can be modified, for example by inclining front portion  440  and rear portion  450  in relation to each other. 
     Optionally, inclination between the front and rear portions is by an actuator  470  which is operable to move at least one of the portions in relation to the other. 
     In some embodiments, modification of the inclination between the front and rear portions may be advantageous in modifying the amount of pressure, which is applied, on the user&#39;s pelvis, for example according to a desired training and/or therapeutic program. 
     In some embodiments, the front portion has inward notch, for example, notch  420  which is shaped to fit the junctional area between the lower abdomen and the thighs. In some embodiments, the rear portion has an inward notch, for example notch  430  which is shaped to fit the junctional area between the lower back and the thighs. 
     In some embodiments, frontal and rear portions are made of a rigid composition which is strong enough to support the weight of the user, when mounted on seat  101 . For example, the portions may bear a weight of up to 350 kg without break. 
     In some embodiments, each of the frontal/rear portions protrude to a characterizing height, defined by the length between central arch  410  and the highest edge each of the protrusions. Optionally, the maximal length is at most +5 cm above the mounted user&#39;s iliac crest. In some embodiments, the length between central arch  410  and the highest edge of each of the protrusions is at most 25 cm, optionally or alternatively, the length is at most 20 cm, optionally or alternatively, the length is at most 15 cm. Such characterizing height may be advantageous in preventing the user from slipping off seat  101 , while avoiding applying pressure on the user&#39;s lower abdomen and back. 
     Surface Area: 
     Referring now to  FIG. 5A  that exemplifies an exemplary body-contact surface area  440  of an exemplary front left protrusion, marked with crosshatches, of seat  101 . 
     In some embodiments, each protrusions has a surface area which is defined between the upper edge of each protrusion and an horizontal line  500  which is at a maximum height of central arch  410 . Optionally, this surface area is in contact which the users pelvis and supports a portion of the user&#39;s body (e.g., the dark areas marked on the body of a user shown for example, at  FIGS. 5B-D ). Optionally, seat  101  include one or more body-contact surface areas. 
     In some embodiments, the body-contact surface area may include the entire upper surface of seat  101 . Optionally, the body-contact surface area is divided into segments. 
     In some embodiments, the body-contact surface area includes both the surface areas of the seat&#39;s front and rear protrusions. Optionally, the body-contact surface area includes the seat&#39;s lateral slopes. 
     In some embodiments, the extent of the surface may vary, according to the size of seat  101  or portions thereof In some embodiments, the extent may vary according to the orientation of parts within seat  101  in relation to each other. For example, the inclination between the frontal and rear protrusions. In some embodiments, as the inclination between the frontal and rear protrusions vary, so as the shape of the seat alters and the extent of the surface area which is in contact with the body of the user alters as well. According to another example, the segments of the seat may move in relation to each other. Optionally, such movement is by one or more joints, positioned between the segments. Optionally, the movement is by actuators, which may move the segments. 
     In some embodiments, the extent of the surface may vary, according to the gap between segments of the seat in relation to each other. For example, the gap between the frontal and rear protrusions. 
     In some embodiments, the extent of the body-contact surface area of each frontal (right or left) protrusion and/or rear protrusion is at most 400 cm 2 . Optionally or alternatively, the surface area of each protrusion is between 5 cm 2  to 400 cm 2 . In some embodiments of the invention, the surface area is between 5 cm 2  to 225 cm 2 , optionally or alternatively, the surface area is between 5 cm 2 to 100 cm 2 . Optionally or alternatively, the surface area is between 5 cm 2 to 25 cm 2 . 
     Optionally or alternatively, the surface area of each protrusion is between 25 cm 2  to 400 cm 2 . In some embodiments of the invention, the surface area is between 100 cm 2  to 225 cm 2 , optionally or alternatively, the surface area is between 225 cm 2  to 400 cm 2 . 
     Referring to  FIG. 6  that shows a perspective front (I-II), side (III) and rear (IV-V) views of an exemplary design of a movable seat  201 , according to some embodiments of the invention. 
     Exemplary Seat Design 
     In some embodiments, seat  201  supports the user from falling off the seat during inclinations of the seat in relation to a frontal and sagittal planes of pelvic training device (PTD)  100 . 
     Optionally, the support is by two lateral portions  105 , that embrace the external sides of the left and right thighs of the user. 
     In some embodiments, lateral portions  105  restrict the pelvis of the user to a region between the two portions, optionally to a region between the inner walls of portions  105 . 
     In some embodiments, lateral portions  105  extends from a rear portion  203  of seat  201  downwardly away from a central arch ( 205 ) which connects the two portions. 
     In some embodiments, seat  201  does not include any additional support engaging the inner side of the user&#39;s thighs excluding central arch  205 , and the user may seat on seat  201  with his thighs adjacent to each other. 
     In some embodiments, a lack of support of the inner portions of the user&#39;s thighs and the location of lateral portions at a side that faces the external portions of the thighs forces the user to straddle his legs towards lateral portions  150  in order to maintain his stability on seat  201 . 
     A potential advantage of supporting the user by lateral portions  105 , which supports the thighs externally, may include training muscle groups which are required for maintaining stability by activating the thighs muscles. 
       FIG. 7  shows a flowchart of a pelvis training method using a pelvic training device 
     (PTD)  100 , according to some embodiments of the invention. 
     In some embodiments, as shown for example, at  FIG. 1B , mounting of a user  111  on a seat  101  includes mounting the user (either by an external assistance, such as by a caregiver and/or by a designated lever or independently) on seat  101 . 
     According to some embodiments, user  111  is optionally fastened to a desired portion of pelvic training device (PTD)  100  at  722 , for example by one or more straps connectable to seat  101 . Optionally, the fastening of the user comprises a securing straps wrapped around a selected portion of the user&#39;s body to a selected portion of pelvic training device (PTD)  100 . Optionally or alternatively, the fastening may include tying the legs of the user to a selected portion of pelvic training device (PTD)  100 . Optionally or alternatively, the fastening may include fastening the thighs of the user  111  adjacently for example to lateral portions (right and left walls) seat  101  (shown for example, at  FIG. 4A ). 
     In some embodiments, the training method includes mounting a user  111  at a starting position as shown at  724  and as exemplified at  FIG. 2A . Optionally, at the starting position the longitudinal axis of seat  101  is aligned parallel with the longitudinal axis of the user&#39;s body and both user and seat  101  are perpendicular to the ground. In some embodiments, the method includes merely maintaining the body and seat  101  stable at the starting position. In some embodiments, maintain stability in the starting position may be advantageous in that it enables beginners which are not familiar with pelvic training device (PTD) 100 to get used to seat&#39;s  101  movements. Optionally, the starting position may be useful for disabled users, which suffer from movements difficulties. 
     In some embodiments, at  726 , the method includes moving seat  101  and moving of the body of the user by movements of the pelvis in relation to the starting position. Optionally, moving includes rotation and/or inclination of the body. 
     In some embodiments, as shown for example at  728 , the user receives an audio and/or a visual signal which indicates a required/current position of one or more a portions of seat  101  in relation to the ground or in relation to other parts of the pelvic training device (PTD). 
     Optionally or alternatively, the signal is displayed on a screen for example a screen of a mobile device  122  and/or a screen as shown for example, at  FIGS. 12-13 . 
     In some embodiments, the visual signal includes movement of an object which is observable by the user in accordance with movement of seat  101 . Optionally, such object may be a ball (as illustrated for example at  FIG. 11 , element  130 ) which may roll inside a channel (e.g., element  129  at  FIG. 11 ) following inclinations of seat  101 . 
     Optionally or alternatively, the user may wear a virtual realty glasses which are in data communication with one or more processing units of the pelvic training device (PTD) device. Optionally, user may receive audio and/or a visual signals through said glasses which may be indicative to a required/current movement/location of seat  101  and/or rotation of vertical supporter  103 . 
     In some embodiments, the signal may include visual and/or audio instructions showing and/or indicating (by an electric and/or a vibration and/or a sound signaling) user  111  to which direction and/or in which movement pattern he should move, in order to improve his stability when mounted on the seat at  730 . 
     Optionally or alternatively, the instructions may include tilting a portion of the user&#39;s body to the left or to the right. Optionally, user may be instructed to rotate a portion of his body either clockwise or counterclockwise. 
     Optionally, the instructions may include a combination of inclinations, for example in relation to a sagittal and/or to a frontal plane of his body. 
     In some embodiments of the invention, at  732 ,  734  and  736 , the training method includes instructions to the user to incline seat  101  and/or rotate vertical supporter  103  at a certain inclination/rotation angle which may be either a large or a small angle. 
     In some embodiments, large angels may require applying greater amount of force compare to smaller angles. Optionally, small angler may require higher precision which may require higher control skill of the device rather than force. 
     In some embodiments, the training method includes a combination of the movements (e.g., inclination and rotation) as mentioned at  732 - 736 . 
     In some embodiments, at  738 , the method includes detection of movements, for example by sensors  125 . Optionally, the sensors include motion sensor and/or a pressure sensor. Optionally, the movements are detected by an image sensor  126  which tracks the location of at least a portion of the user&#39;s body/location of one or more parts of pelvic training device (PTD)  100 . 
     In some embodiments, the method includes transmitting one or more signals received by the sensors to processing unit  118 . Optionally, processing unit  118  transmits an electric signal to a speaker and/or to a displaying unit, which is observable by the user. Optionally, the signal include usage instructions. 
     In some embodiments, at  740 , the method optionally includes displaying the inclination of the seat by a movable object (e.g., a ball which shown for example at  FIG. 11 , element  130 ). 
     In some embodiments, at  742 , the training method includes a training protocol. 
     Optionally, the protocol includes one or more instruction regarding a desired seat inclination (frontal, rear and/or lateral) in a desired direction and/or rotation (clockwise and/or counterclockwise) that the user needs to perform while being mounted on the seat. Optionally, the protocol includes repetitions of certain movements. 
     In some embodiments, at  744  the training method includes terminating the training and getting off the seat. 
     According to some embodiments, user is optionally un-fastened from pelvic training device (PTD)  100 . 
     In some embodiments, the step includes lowering the body of the user (either by an external assistance, such as by a caregiver/or a designated lever or independently) to the height of the ground. 
     Reference is Now Made to FIGS.  8 A and  8 B. 
       FIG. 8A  shows a perspective front view of a user  111  using an exemplary embodiment of pelvic training device (PTD)  100 . The figure exemplifies a left lateral inclination of the user&#39;s body in relation to the ground (shown as angle β)  FIG. 8B  exemplifies a rear inclination of the user&#39;s body in relation to the ground (shown as angle α). In some embodiments, user  111  is supported on pelvic training device (PTD)  100  by one or more gripping points which are connectable to his body, e.g., by at least one strap  113 . In some embodiments, user  111  may hold straps  113  by his hands and/or may tie straps  113  to a selected portion of his body (e.g., the ankle and/or the waist). 
     Referring to  FIG. 9  that shows some exemplary training poses according to the pelvis and/or core muscles training method which are enabled by pelvic training device (PTD)  100 . 
     It is expected that the given postures are just an example of the different body orientations that are enabled by the pelvic training device (PTD) and the training method. In addition, it is expected that the training method include training exercises that require movement of the body in a certain direction (at X, Y, and Z axis), while using pelvic training device (PTD)  100  in order to reach the desired posture/s. 
     In some embodiments, the method include a native standing position. Optionally, the native pose includes stabilizing the body on seat  101  while the beck of the user is kept upright (perpendicular to the ground). 
     In some embodiments, the method include a sitting position. Optionally, the sitting position includes stabilizing the body on seat  101  during rear inclination of seat  101  by the user&#39;s pelvis, while the back of the user remains upright (perpendicular to the ground). 
     In some embodiments, the method includes swiveling position. Optionally, the swiveling position includes stabilizing the body on seat  101  during rotation of seat  101  about its longitudinal axis by the user&#39;s pelvis. 
     In some embodiments, the method includes lateral inclination position. Optionally, the lateral inclination position includes stabilizing the body on seat  101  during inclination of seat  101  laterally (left or right) in relation to a sagittal plane of the user&#39;s body or of the pelvic training device (PTD)  100 . 
     In some embodiments, the method includes frontal/rear inclination position. Optionally, the frontal/rear inclination includes stabilizing the body on seat  101  during inclination of seat  101  to the front or to the rear in relation to a frontal plane of the user&#39;s body or of the pelvic training device (PTD)  100 . 
     In some embodiments, the method includes a combination of poses, for example native, sitting, swiveling, lateral rear and frontal position or any combination thereof. 
     In some embodiments, the method includes transition between poses, for example user may stabilize himself of seat  101  at a native pose and change his position to a sitting position. 
     In some embodiments, the training method includes postures that engage holding straps, as shown for example at figures I-VI. 
     In some embodiments, the user may hold straps which are connected to the peripheral frame or to any other anchoring point around the seat, and tilt his body to a desired direction, for example backwards (I, IV), forwards (V, VI) laterally (II, III) and/or may rotate his body (II, III) or combination thereof. In some embodiments, the training method includes postures that engage tying straps to the leg, as shown for example at figures VII-VIII. 
     In some embodiments, the user may tie straps which are connected to the peripheral frame or to any other anchoring point around the seat to his legs and/or to other parts of his body, and tilt his body to a desired direction, for example backwards (VIII), forwards, laterally (VII) and/or may rotate his body (VI) or combination thereof. 
     In some embodiments, the training method includes postures that do not require connection of straps, as shown for example at figures IX-XII. 
     Referring to  FIG. 10  which shows a frontal (I), a perspective (II), and a side (III&amp;IV) views of an exemplary design of seat  101 , according to some embodiments of the invention. 
     In some embodiments, seat  101  includes two spheres or spheres sections. Optionally, the spheres are sized and shaped to fit the curvature of the user&#39;s body. Optionally, the spheres support the user&#39;s body. In some embodiments, the spheres are inflatable. 
     In some embodiments, seat  101  comprises a front portion  127  which is optionally shaped as a sphere. Optionally or alternatively, front portion  127  may comprise a curved shape. Optionally, portion  127  may be inflated to a curved shape. Optionally, seat  101  includes another shape which is also shaped as a sphere  128 , attached to its rear portion, as shown for example at  FIG. 10  (II). In some embodiments, front portion  127  and rear portion  128  may be shaped as a dome. Optionally, the front and rear portions may include one or more concaved portions on its surface area. 
     In some embodiments of the invention, each of the spheres (frontal  127  and rear  128 ) may have an equal diameter in respect to the other. Optionally or alternatively, one sphere may have a larger diameter than the other. 
     Optionally, the diameter of at least one of the spheres is between 40 cm to 120 cm. Optionally, the diameter is between 40 cm to 80 cm. Optionally or alternatively, the diameter of the sphere is between 80 cm to 120 cm. 
     Optionally, when the seat is inclined forwards or backwards, the user may lean his body onto the surface of front sphere  127  or rear sphere  128  and grasp the sphere with his arms. Optionally, the sphere is pliable and may bend according to the curvature of the abdomen and chest or back of the user. 
     In some embodiments, a sphere-shaped frontal and/or rear portion attached to seat  101  may be advantageous for supporting the user&#39;s body when seat  101  is inclined in relation to the sagittal and/or frontal planes of the user&#39;s body. 
     Referring to  FIG. 11  which show a pelvic training device (PTD)  100  comprises a movable ball  130 , according to some embodiments of the invention. 
     In some embodiments, ball  130  is free to roll inside channel  129 , according to the inclination of seat  101 . In some embodiments of the invention, the location and/or movement of ball  130  inside peripheral channel  29  is indicative to user  111  regarding his inclination in relation to the ground. For example, a right lateral inclination may result in movement of the ball to the right side of channel  129 . 
     In some embodiments, ball  130  moves inside a peripheral (circumferential) channel  129 , which is attached to seat  101 . Optionally, peripheral channel  29  serves as a housing for movable ball  130  and moves in accordance with the inclination of seat  101 . Optionally, the attachment of peripheral channel  29  to seat  101  is by one or more rods extending between seat  101  and peripheral channel  129 . In some embodiments, as seat  101  inclines, so as the peripheral channel inclines at the same inclination angel and at the same direction. 
     In some embodiments, peripheral channel  129  comprises a characterizing width. Optionally, the diameter of ball  130  is smaller than the width of channel  129  thereby ball  130  may roll in channel  129  freely, according to the inclination of channel  129 . 
     Referring to  FIGS. 12 and 13  which show an exemplary schematic representation of the location of a user&#39;s body&#39;s center of gravity (marked as a black dot) represented on an exemplary GUI (graphic user interface). 
     In some embodiments, the location of the center of gravity is determined (calculated) by the usage parameters of the device and by physical parameters of the user. 
     In some embodiments, representation of the center of gravity is by a software embedded in a processing unit (e.g., processing unit  118  at  FIG. 1A ). Optionally, processing unit  118  is in data communication with a screen onto the GUI is presented. Optionally, the software receives data from the inertial and/or pressure sensors and translates the signals to a visual output. 
     In some embodiments, the location center of the center of gravity is presented in relation to a desired pre-defined location which is presented as a center of a cross. Optionally, the location of center of gravity is presented to the user when the user is mounted on pelvic training device (PTD)  100  (shown for example at  FIG. 1A ). 
     In some embodiments of the invention, the GUI may be presented on a screen, for example a screen of a displaying unit such as smartphone. Optionally, the presentation is performed at real time. 
     Optionally, the location and/or to the movement of one or more portions of the mounted user may cause shifting of the presented location of the center of gravity (dot) in relation to the presented pre-determined presented starting point/location (center of the cross). 
     In some embodiments of the invention, the center of gravity (dot) may be presented as overlapping with the presented center of the cross, for example when the user is mounted at a starting position. 
     Optionally or alternatively, the location of the presented starting point may be calibrated according to any desired pre-determined location and/or inclination of the seat. 
       FIG. 13  shows an exemplary schematic GUI (graphic user interface) which displays motion and/or pressure parameters while using the pelvic training device (PTD). In some embodiments, pressure applied by the user&#39;s pelvis and thighs on different portions of the seat is displayed. The figure displays data which is acquired by sensors which are embedded in the pelvic training device (PTD). 
     In some embodiments, the GUI may include a table. Optionally, the GUI may include a graph or combination thereof. In some embodiments, the table may be divided into one or more columns, each represents a portion of seat  101  (e.g., a left/right/frontal/rear side of the seat.) 
     In some embodiments, the table may include one or more rows, in which usage parameters, such as applied pressure and/or movement parameters per seat&#39;s portion may be presented. 
     Optionally, the data may include pressure which is applied by portions of the user&#39;s pelvis on portions of the seat, for example on seat-body contact area (as shown for example, at  FIG. 5 ). In some embodiments, the data may include representation of movements of the seat while it moves in certain directions. 
     In some embodiments, the representation includes a color gradient. Optionally, the representation is represented by a graph that shows for example a measured pressure vs. time. In some embodiments, the representation includes a surface map. 
     In some embodiments, the GUI may include a planned usage vs. actual usage parameter&#39;s representation. For example, a planned pressure on a certain portion of the seat (for example on the front portion) may be presented as dashed surface map which is being filled by color as the deviation of pressure which is applied by the user on the selected seat portion becomes smaller or larger. 
     In some embodiments, representation may be advantageous in providing real time data, regarding the manner by which a certain posture of the user&#39;s body produces a pressure pattern on portions of the seat. 
     Optionally, the representation may be indicative for example for detection of some physiologic deformities (e.g., pelvis and/or core muscles inferior function) and/or muscles reduced/enhanced activation level. 
       FIGS. 14-19  show perspective views of an exemplary design of a segmented seat, according to some embodiments of the invention. 
     The figures show exemplary configurations of a segmented seat, for example a folded or an un-folded configuration. 
     In some embodiments, the figures show means for altering the orientation (e.g., the inclination and/or the position) of portions of the segmented seat in relation to each other. 
     Referring now to  FIG. 14  (I-IV) that show a perspective views of an exemplary design of a segmented seat  1400 , according to some embodiments of the invention. In some embodiments, seat  1400  comprises one or more frontal and rear portions  1401 . Optionally, each of the frontal and rear portions  1401  contacts the frontal and rear portions of the user&#39;s pelvis respectively. 
     Referring now to  FIG. 15 (I-IV) that shows a movable segmented seat  1500 , comprising one or more separated movable lateral portions  1502 . Optionally, each of lateral portions  1502  contacts the external sides of the left and right thighs of a user respectively. 
     In some embodiments, lateral portions  1502  are connected to each other or to another portion of seat  1500  by a joint (not shown) disposed between lateral portions  1502  and a portion of seat  1500 . Optionally, lateral portions  1502  may be folded downwards (e.g., folded configuration) and/or may be un-folded (e.g., un-folded configuration). In some embodiments, a folded configuration may force the user to spread his legs apart from each other to a smaller straddle. 
     Optionally, an un-folded configuration may force the user to widen his straddle which may affect traction of his hip joint. 
     Optionally, lateral portions  1502  may be partially folded. In some embodiments, movement of lateral portions  1502  may be modified by an actuator, for example actuator  1506 , (e.g., an electric motor) which is connected to the lateral portions and to at least another portion of seat  1500 , and inclines each lateral portion  1502  to a desired inclination. Optionally, actuator  1506  may be operable according to a control signals which may be transmitted from/to a control unit (e.g., control unit  118 , shown at  FIG. 1A ). 
     In some embodiments, lateral portions  1502  may move in relation to each other for example by a ratchet assembly (illustrated as a dashed line  1506 ) which allows a linear movement which may result of inclination of lateral portion  1502  in only one direction. Optionally, ratchet assembly  1506  may prevent motion (e.g., inclination) in the opposite direction. 
     In some embodiments, inclination of lateral portions  1502  causes traction of the hip joint, for example in accordance with an inclination of lateral portions  1502  in relation to the longitudinal axis of pelvic training device (PTD)  100 . In some embodiments of the invention, a modified inclination of lateral portions  1502  forces the user to apply a modified amount of pressure with his legs laterally, in a direction towards or away lateral portions  1502  of seat  1500  in order to maintain his stability. 
     In some embodiments, the frontal/rear portions  1501  are connected to each other or to another portion of seat  1500  by a joint (e.g., joint  1504 ). Optionally, frontal/rear portions  1501  may move in relation to each other. Optionally, frontal/rear portions  1501  may be inclined in relation to the longitudinal axis of pelvic training device (PTD)  100 . Optionally, frontal/rear portions  1501  may be folded downwards (for example as shown at  FIG. 15  (II)) and/or may be un-folded (for example as shown at  FIG. 15  (I)). In some embodiments, movement of frontal/rear portions  1501  may be by one or more actuators, e.g., an electric motor. In some embodiments, the actuator may be connected to the frontal/rear portions  1501  and incline each of frontal/rear portions  1501  at a desired inclination angle. 
     Referring now to  FIG. 16  that shows a perspective view of an exemplary segmented seat  1600 , according to some embodiments of the invention. In some embodiments, a gap between portions (e.g., portions  1602 ) of seat  1600  can be modified. Optionally, such modification includes adjustment of the size and/or the shape of the seat in accordance with the user&#39;s size. Optionally, such adjustment can be in accordance with a desired training protocol. For example, if a loose attachment between the pelvis and portions of seat  1600  (e.g., rear or front portions  1601 ) is required, the gap between the portions (e.g.,  1601  and  1602 ) of seat  1600  can be enlarged and vice versa. 
     In some embodiments, the gap between portions of seat  1600  as exemplified for example at  FIG. 16  can be modified by inclination of parts of the seat  1600  in relation to each other, as exemplified for example at  FIG. 15 . 
     Referring now to  FIG. 17 , which shows a perspective top view of an exemplary segmented seat  1700 , according to some embodiments of the invention. The figure exemplifies the location of portions (e.g., portions  1701  and  1702 ) of seat  1700  in relation to each other. In some embodiments, portions  1701  and  1702  may be positioned apart from each other. Optionally or alternatively, portions  1701  may be positioned adjacent to each other. Optionally, modification of the distance between two or more portions of seat  1700  is by a joint/assembly  1703  (illustrated as a cross-hatched cross), poisoned between two or more pars. 
     In some embodiments, the size and/or shape of joint/assembly  1703  is adjustable. For example, joint/assembly  1703  may be segmented into two or more pieces assembled as a telescopic assembly. In some embodiments, joint  1703  includes a nested configuration wherein at least one portion of the joint is nested in another portion. Optionally, assembly  1703  includes an un-nested configuration, wherein none of the portions are nested. 
     Optionally or alternatively, cross-hatched cross  1703  illustrates a ratchet assembly which may mechanically couple adjacent parts of seat  1700  to each other. Optionally, ratchet assembly may move two or more coupled pars of seat  1700  away and/or towards each other. 
     Referring now to  FIG. 18  which shows a perspective view of an exemplary segmented seat  1800  mounted above the ground by an exemplary vertical supporter  1806 , according to some embodiments of the invention. Optionally, modification of the height of seat  1800  along with modification of the distance between parts of seat  1800 , along with movement of seat  1800  (inclination/rotation) is performed simultaneously, thereby allowing different training difficulties, be enabling various postures. 
     In some embodiments, modification of the shape of seat  1800  (e.g. inclination between parts of the seat and/or distance between two or more adjacent parts) is by joint/assembly as described for example, at  FIG. 17 . Optionally, the joint/assembly includes a ratchet or a rail connected to two or more parts of the seat and operable to move a selected potion (e.g., portion  1801  and/or  1802 ) in relation to each other, as explained for example at  FIG. 19 . 
     In some embodiments, an optional flexible connector  1803  connects a bottom of the seat  1800  to the vertical supporter  1806 , potentially enabling the seat to “wobble” relative to the vertical supporter  1806 . 
     In some embodiments, an optional spring  1805  serves to press against a bottom of the flexible connector  1803 , potentially setting stiffen of the “wobbling”. 
     Referring now to  FIG. 19  shows a perspective view of an exemplary segmented seat  1900 . 
     In some embodiments, rear portion  1922  and front portion  1902  may move away or towards each other, for example by sliding on frame  1908 . Optionally, the portions are mechanical coupled to frame  1908  by rail  1914 , on which the portions may slide. Optionally, the distance between front portions  1902  and rear portions  1922  is modified according to their location on frame  1908  and/or on rail  1914 . 
     In some embodiments, the inclination of front portions  1902  and rear  1922  in relation to each other and/or in relation to the ground is modified, for example by joint  1910 . In some embodiments, front portions  1902  and/or rear portions  1922  may incline at an inclination angle in relation to the ground and/or in relation to the longitudinal axis of pelvic training device (PTD)  100 , for example at an inclination angle between 0° (parallel to the longitudinal axis) to 90° (perpendicular to the longitudinal axis). 
     In some embodiments, movement of rear portions  1922  and/or front portions  1902  is adjusted by a screw  1906 . Optionally, screw  1906  is mechanically coupled with rail  1914 . Optionally, by threading screw  1906  into frame  1908 , rail  1914  is pushed or pulled away or towards frame  1908  and the gap between rear portions  1922  and front portions  1902  is modified. 
     In some embodiments, lateral portion  1904  moves along frame  1908 . Optionally, lateral portions  1904  may move on frame  1908  by sliding on a rail  1914 . 
     In some embodiments, the inclination of one or more lateral portions  1904  in relation to each other and/or in relation to the ground is modified, for example by a joint  19016  (shown as white cross). In some embodiments, lateral portions  1904  may incline at an inclination angle in relation to the ground and/or in relation to the longitudinal axis of pelvic training device (PTD)  100 , for example at an inclination angle between 0° to 90°. 
     In some embodiments, movement of rear portions  1922  and/or front portions  1902  and/or lateral portions  1904  in relation to each other is by one or more actuators (such as joints  1910 / 1916 ). Optionally, the actuators are motorized and operable to receive and/or transmit data to/from one or more control units (e.g. control unit  118  and/or remoted control unit  121  and/or  122  and/or external server  123  (shown, for example, at  FIG. 1A )). 
     In some embodiments,  FIGS. 14 to 23C  illustrate exemplary configurations of the same segmented seat according to some embodiments of the invention. 
     Referring now to  FIGS. 20A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention. 
       FIGS. 20A-C  show an example embodiment of a “wobbly” seat which serves as a pelvis training system  2000 . The term “wobbly” seat in all its grammatical forms is used throughout the present specification and claims interchangeably with the term “seat pelvis exercising system” and its corresponding grammatical forms. The “wobbly” seat optionally tilts side-to-side and/or front-to-back and/or rotates side-to-side, and a user sitting on the seat adjusts his balance, using and/or exercising different muscles for different tilt angles and/or tilt directions relative to the user&#39;s torso. 
       FIG. 20A  shows an isometric view from a left side of a pelvis training device (PTD)  2000 ,  FIG. 20B  shows an isometric view from a left-front side of the PTD  2000 , and  FIG. 20C  shows an isometric view from a left-back side of the PTD  2000 . 
     The PTD  2000  includes a seat  2001  on which a user may sit. 
     In some embodiments, the seat  2001  is mounted to a flexible connector  2002 , for example a spring (or more than one spring) on a vertical supporter  2003 . In some embodiments, the spring  2002  supports movement of the seat  2001  relative to other parts of the PTD  2000  or relative to the ground. Optionally, the spring  2002  connects the seat  2001  to the vertical supporter  2003 . 
     In some embodiments, the seat  2001  is mounted to a vertical supporter  2003 , and a flexible connector  2002 , for example a spring (or more than one spring) on the vertical supporter  2003 , provides movement along an axis of the vertical supporter  2003 . 
     In some embodiments, the PTD  2000  includes an interface (e.g., a seat  2001 ) on which a user is mounted. Optionally, the interface supports a portion of the user&#39;s body such as the area between the lower abdomen and the bottom of the pelvis. Optionally, the interface supports the user also by his thighs. 
     In some embodiments the PTD  2000  optionally includes a back support  2010 , connected to the seat  2001  or to the vertical supporter  2003 , or to the spring(s)  2002 , by a back strut  2012 . In some embodiments, an optional control  2013  serves to set a distance between the back strut  2012  and the seat  2001 . 
     In some embodiments the PTD  2000  optionally includes a locking prong  2016 , optionally connected to a hinge  2014 . The locking prong  2016  is optionally pushed into the spring(s)  2002 , locking their movement, thereby optionally locking the seat  2001  at a fixed tilt or position. 
     In some embodiments the PTD  2000  the locking prong  2016  is optionally connected to the back strut  2012 . In some embodiments, a user may optionally push the back strut backward, optionally causing the locking prong  2016  to lock the seat  2001 . In some embodiments, the user may optionally lean back against the back cushion  2010 , optionally causing the locking prong  2016  to lock the seat  2001 . 
     In some embodiments, various controls as described herein may optionally be used to lock and unlock movement of the seat  2001  relative to the feet  2018 . 
     In some embodiments, the locking/unlocking are optionally performed by a user leaning back, forcing the locking prong  2016  to lock the seat  2001 . 
     In some embodiments, the locking/unlocking are optionally performed by a user operating a handle, forcing the locking prong  2016  to lock the seat  2001 . 
     In some embodiments, the locking/unlocking are optionally performed by a user operating an under-seat handle, forcing the locking prong  2016  to lock the seat  2001 . 
     In some embodiments, the locking/unlocking are optionally performed by a user operating a pedal, forcing the locking prong  2016  to lock the seat  2001 . 
     In some embodiments the vertical supporter  2003  is optionally connected to one or more feet  2018 . 
     In some embodiments the feet  2018  include wheels  2019 . 
     In some embodiments the vertical supporter  2003  is optionally connected to one or more spring(s)  2022 . The spring(s)  2022  optionally provide(s) a centering force returning the seat  2001  to a center-facing position when a user optionally rotates the seat  2001  clockwise or counterclockwise relative to the feet  2018 . In some embodiments the spring(s)  2022  is/are connected to the vertical supporter  2003  and to the feet  2018 , as shown in  FIGS. 20A-20C . 
     In some embodiments the PTD  2000  optionally includes controls  2024   2026 . 
     In some embodiments, one or more controls such as the  2024   2026  is/are configured for setting stiffness of the spring(s)  2002   2022 . 
     In some embodiments, one or more of the controls, such as the  2024   2026  is configured for adjusting length of the vertical supporter  2003 , which adjusts height of the seat  2001  off the floor. 
     In some embodiments, the various controls may tighten or release as screws, or by using other mechanical mechanisms such as inclines planes, rotating logs, rotating eccentric components, as are known in the art. 
     In some embodiments, the PTD  2000  is made for adult users. Optionally, each part of the device can bear a weight of, for example, 0-350 kg, 0-150 kg, 150-200 kg, 200-300 kg and 300-350 kg static or dynamic, without breaking and/or plastically deforming. 
     In some embodiments, each part of the PTD  2000  can bear loads for example of between 0 to 3500 N, 0-1500 N, 1500-2000 N, 2000-3000 N and 3000-3500 N without breaking and/or plastically deforming. 
     In some embodiments, the seat  2001  is saddle shaped. Optionally the seat comprises one or more convex portions (such as, e.g., portions  440  and  450  at  FIG. 4A ), optionally positioned at a front portion of the seat  2301  (in front of the mounted user) and at a rear portion of the seat  2001  (behind the mounted user). In some embodiments, the seat  2001  includes one or more concave portions (such as, e.g., portions  460  at  FIG. 4A ). In some embodiments, the concave portions are optionally positioned between the front portion and the rear portions, in vicinity of the thighs of a mounted user (e.g., lateral portions). 
     In some embodiments, the seat  2001  includes a central arch (such as, e.g., portion  410  at  FIG. 4A ) positioned between the convex portions and the concave portions. In some embodiments, the central arch comprises a saddle point. In some embodiments, each of the convex portions extends upwardly away from the arch. In some embodiments, each of the concave portions extends downwardly away from the arch. In some embodiments, the height of each of the convex portions, which is defined as the height above the central arch, does not exceed the height of the user&#39;s ilia bones. 
     In some embodiments, the distance between the front and rear convex portions is long enough to house the pelvis of the user. Optionally, the distance is at most 40 cm. optionally or alternatively, the distance is at most 35 cm, 30 cm. 
     Optionally, the distance is between 20 cm to 40 cm. optionally, the distance is between 20 cm to 35 cm. optionally, the distance is between 20 cm to 30 cm. 
     In some embodiments, the height of seat  2001  above the ground is defined by the length of the vertical supporter  2003 , the seat  2001  is mounted on a distal end (in relation to the ground) of the vertical supporter  2003 . 
     In some embodiments of the invention, a user (shown for example, at  FIG. 1B ) is forced to stabilize himself on the seat  2001  by activating the muscles of his pelvis and thighs and/or his inner core-muscles; this activation may be advantageous in training these body areas. 
     In some embodiments, the seat  2001  has a fixed size and/or shape. Optionally or alternatively, as shown for example at  FIG. 15 , seat  2301  may comprise one or more portions (for example such as one or more frontal  1501  portions, one or more rear  1501  portions, and one or more lateral  1502  portions in  FIG. 15 ). In some embodiments, the portions of the seat  2301  may move in relation to each other, thereby to adjust the size and/or shape of the seat. Potential benefits of adjusting the location and/or extent of contact area between the seat and the user&#39;s is forcing the user to apply modified amount of force on parts of the seat to maintain his stability. 
     In some embodiments, the flexible connector (e.g., spring)  2002  may be bent in relation to the ground and/or in relation to the vertical supporter  2003  following force which is applied on the seat  2001 . In some embodiments, the inclination of the spring  2002  may be at any positive or negative inclination angle in relation to a sagittal/frontal plane of the PTD  2000  and/or in relation to a sagittal/frontal plane of the user&#39;s body. In some embodiments, the inclination is between 0 to 180 degrees. In some embodiments, the inclination to about 180 degrees may be advantageous in forcing the user to activate additional muscles as part of the wide range movement. In some embodiments, such a wide range of movement is by supporting portions of his body (e.g., legs and/or hands) to additional straps. 
     Optionally, the inclination is between 0 to 150 degrees. Optionally or alternatively, the inclination is between 0 to 90 degrees. In some embodiments, inclination between 0 to 90 degrees may be advantageous in training the user to perform small range movements (e.g., movements that requires pelvis movements within 10, 15, 20 degrees while being inclined) to increase precise and control of his muscle. Optionally or alternatively, the inclination is between 0 to 75 degrees. Optionally or alternatively, the inclination is between 0 to 50 degrees. In some embodiments, inclination is between 0 to 25 degrees, or at any angle between 0 to 180 degrees. 
     In some embodiments, movements of the seat  2001  include inclination and/or rotation or combination of such movements. Optionally, movements are initiated by a user, or by activation of one or more actuators, for example such as actuators  117  shown in  FIG. 1A . In some embodiments, the actuators may be mounted to or integral with one or more parts of the PTD  2000 , for example, with vertical supporter  2003 , spring  2002  and/or with seat  2001 . In some embodiments, the actuators are operable to cause movements of one or more parts of the PTD  2000  in relation to the rest of the PTD  2000 . In some embodiments, the actuators are optionally powered by one or more of electricity and/or pneumatic and/or hydraulic pressure. 
     In some embodiments, the seat  2001  may rotate following rotation of the vertical supporter  2003  which may rotate about a bearing. Optionally, the vertical supporter  2003  may rotate following activation of an actuator. 
     In some embodiments, the actuator is controlled by a control signal, provided, for example, by a controller (e.g., control unit) such as the controller  118  shown in  FIG. 1A . 
     In some embodiments, the flexible connector  2002  includes two or more segments having a degree of movement freedom in relation to each other. In some embodiments, a joint is positioned underneath the seat  2001 , wherein at least one end of the joint is connected to the seat  2001  and at least a second side of the joint is connected to the vertical supporter  2003 . In some embodiments, the flexible connector  2002  couples the seat  2001  with the vertical supporter  2003 . In some embodiments, the joint is a multidirectional joint, operable to allow movement at multiple axial (e.g., X, Y and Z) directions and in relation to the sagittal and/or to the frontal planes of the PTD  2000 . 
     In some embodiments, the vertical supporter  2003  is mounted perpendicular to feet  2018 . In some embodiments, the seat  2001  is mounted directly on the vertical supporter  2003 . 
     Rigidness: In some embodiments, the vertical supporter  2003  is formed of a rigid material, such as a polymer and/or metal or combination thereof. Optionally, the vertical supporter  2003  is rigid enough to bear a weight of an adult user without bending or breaking. For example, the vertical supporter  2003  may bend up to 10 degrees without breaking at a static weight of up to 350 kg. 
     In some embodiments, the vertical supporter  2003  supports the seat  2001  above the ground at a height which is at least higher than 60 cm. Optionally or alternatively, at a height which is at least higher than 70 cm. Optionally or alternatively, at a height which is at least higher than 80 cm. Optionally or alternatively, at a height which is at least higher than 90 cm. Optionally or alternatively, at a height which is at least higher than 100 cm. 
     In some embodiments, the vertical supporter  2003  may have a length between 30 and 80 cm, or between 30 cm and 140 cm, for example, between 30 cm and 100 cm and/or between 100 cm and 140 cm or at any intermediate length between them or a greater or smaller length. 
     Optionally or alternatively, the length of vertical supporter  2003  is adjustable. For example, the vertical supporter  2003  may be segmented into one or more pieces assembled as a telescopic assembly. Optionally, the assembly includes a nested configuration wherein at least one segment is nested in another segment. Optionally, the assembly includes an un-nested configuration, wherein none of the segments are nested. 
     Vertical Supporter Rotation: 
     In some embodiments, one or more retrieval springs extend between the vertical supporter  2003  and a portion of the feet  2018 . Optionally, the vertical supporter  2003  is maintained at and/or returned to a resting position by the retrieval springs, following rotation thereof. 
     Optionally, two retrieval springs  2022  are connected perpendicularly to the vertical supporter  2003  at opposite sides of the vertical supporter  2003  and pull the vertical supporter  2003  in opposite directions, potentially defining a stable resting position. 
     In some embodiments, sensor(s) such as described with reference to the embodiments described herein may be included in the embodiments shown in  FIGS. 20A-C ,  21 A-C,  22 A-C and  23 A-C. 
     In some embodiments, body sensor(s) such as described with reference to the embodiments described herein may be included in the embodiments shown in  FIGS. 20A-C ,  21 A-C,  22 A-C and  23 A-C. 
     In some embodiments, image sensor(s) such as described with reference to the embodiments described herein may be included in the embodiments shown in  FIGS. 20A-C ,  21 A-C,  22 A-C and  23 A-C. 
     In some embodiments, connectivity to external devices such as described with reference to the embodiments described herein may be included in the embodiments shown in  FIGS. 20A-C ,  21 A-C,  22 A-C and  23 A-C. 
     Additionally referring now to  FIGS. 21A-C  show schematic illustrations of the pelvis training system shown by  FIGS. 20A-20C . 
       FIG. 21A  shows an isometric view from a left side of the PTD  2000 ,  FIG. 21B  shows an isometric view of a cut-out of the PTD  2000  as seen from the left side, and  FIG. 21C  shows an isometric view from a left-back side of the PTD  2000 . 
       FIGS. 21A-C  show the example embodiment shown by  FIGS. 20A-20C  in some more detail.  FIGS. 21A-C , show how, in some embodiments, the locking prong  2016  turns on the hinge  2014  and is pushed into the spring(s)  2002 , when the back strut  2012  is pushed back. 
     Referring now to  FIGS. 22A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention. 
       FIGS. 22A-C  show an example embodiment of a “wobbly” seat which serves as a PTD  2200 . The “wobbly” seat optionally tilts side-to-side and front-to-back, and a user sitting on the seat adjusts his balance, using and/or exercising different muscles for different tilt angles and/or tilt directions relative to the user&#39;s torso. 
       FIG. 22A  shows an isometric view from a left side of the PTD  2000 ,  FIG. 22B  shows an isometric view from a left-back side of the PTD  2000 , and  FIG. 22C  shows details of a base portion of the PTD  2000 . 
     The PTD  2000  includes a seat  2201  on which a user may sit. 
     The seat  2201  is mounted on a vertical supporter  2003 , which can provide movement side-to-side and up and down (along an axis of the vertical supporter  2203 ). 
     In some embodiments, the vertical supporter is attached to a base  2218 . 
     Optionally, the vertical supporter  2203  includes one or more spring(s)  2202  which enable compressing under a weight of a user and expanding when the user raises himself. In some embodiments, the spring(s)  2202  may be replaced by a gas strut (not shown). 
     Optionally, a bottom portion  2220  of the vertical supporter  2203  enables the vertical supporter  2203  to change angle, relative to the floor or to the base  2218 , so the seat  2201  can move side-to-side and/or forward and back. In some embodiments a range of movement of the vertical supporter  2203  is optionally in a range from +10 degrees to −10 degrees. In some embodiments a range of movement of the vertical supporter  2203  is optionally in a range from +30 degrees to −30 degrees. In some embodiments a range of movement of the vertical supporter  2203  is optionally in a range from +45 degrees to −45 degrees. In some embodiments a range of movement of the vertical supporter  2203  is optionally in a range from +60 degrees to −60 degrees. 
     In some embodiments, the range of movement of the vertical supporter  2203  is not the same side-to-side as forward to back. 
     In some embodiments, the range of sideways movement of the vertical supporter  2203  is from 10 degree right to 10 degrees left. 
     In some embodiments, the range of front-to-back movement of the vertical supporter  2203  is from 10 degree front to approximately 0 degrees back (that is, approximately vertical). 
     In some embodiments, the range of front-to-back movement of the vertical supporter  2203  is from 10 degree front to approximately 2 degrees front, that is, the vertical supporter  2203  does not lean back from vertical. 
     In some embodiments the PTD  2200  optionally includes a locking prong  2222 , which can be moved to lock the vertical supporter  2203  from moving side-to-side and/or front-to-back. 
     In some embodiments, the locking prong  2222  is mounted on a hinge  2214 , and connected to a strut  2212  which serves to move the locking prong  2222  into and out of locking the vertical supporter  2203 . 
     In some embodiments, the strut  2212  is optionally long, and attaches to a back cushion  2210 . A user can optionally lock the vertical supporter from side-to-side and/or front-and-back movement by leaning back upon the back cushion  2210 . 
     Referring now to  FIGS. 23A-C  show schematic illustrations of a pelvis training system, according to some embodiments of the invention. 
       FIGS. 23A-C  show an example embodiment of a “wobbly” seat which serves as a PTD  2300 . The “wobbly” seat optionally tilts side-to-side and/or front-to-back, and a user sitting on the seat adjusts his balance, using and/or exercising different muscles for different tilt angles and/or tilt directions relative to the user&#39;s torso. 
       FIG. 23A  shows an isometric view from a back side of the PTD  2300 ,  FIG. 23B  shows an isometric view from a front side of the PTD  2300 , and  FIG. 23C  shows an isometric view from a right side of the PTD  2300 . 
     The PTD  2300  includes a seat  2301  on which a user may sit. 
     In some embodiments, the seat  2301  is mounted to a flexible connector  2304 , for example a spring (or more than one spring) on a vertical supporter  2303 . In some embodiments, the spring supports movement of the seat  2301  relative to other parts of the PTD  2300  or relative to the ground. Optionally, the spring connects the seat  2301  to the vertical supporter  2303 . 
     In some embodiments, the seat  2301  is mounted to a vertical supporter  2303 , and a flexible connector  2304 , for example a spring (or more than one spring) on the vertical supporter  2303 , provides movement along an axis of the vertical supporter  2303 . 
     In some embodiments, the PTD  2300  includes an interface (e.g., a seat  2301 ) on which a user is mounted. Optionally, the interface supports a portion of the user&#39;s body such as the area between the lower abdomen and the bottom of the pelvis. Optionally, the interface supports the user also by his thighs. 
     In some embodiments the PTD  2300  optionally includes a back support  2310 , connected to the seat  2301  or to the vertical supporter  2303 , or to the spring(s)  2304 , by a back strut  2312 . 
     In some embodiments the PTD  2300  optionally includes a locking prong, such as shows in  FIGS. 20A-C ,  21 A-C,  22 A-C and  24 A-E. The locking prong is optionally pushed into the spring(s)  2304 , locking their movement, thereby optionally locking the seat  2301  at a fixed tilt or position. 
     In some embodiments of the PTD  2300  the locking prong is optionally connected to a back strut  2312 . In some embodiments, a user may optionally push the back strut  2312  backward, optionally causing the locking prong to lock the seat  2301 . In some embodiments, the user may optionally lean back against the back cushion  2310 , optionally causing the locking prong to lock the seat  2301 . 
     In some embodiments the vertical supporter  2303  is optionally connected to one or more feet  2318 . 
     In some embodiments the feet  2318  include wheels  2319 . 
     In some embodiments the vertical supporter  2303  is optionally connected to one or more spring(s)  2320 . The spring(s)  2320  potentially exert a centering force returning the seat  2301  to a center position if a user chooses to rotate the seat  2301  clockwise or counter-clockwise relative to the feet  2318 . 
     In some embodiments the PTD  2300  optionally includes one or more controls  2305 . 
     In some embodiments, one or more of the controls  2305  is configured for setting stiffness of the spring(s)  2304 . 
     In some embodiments, one or more of the controls  2305  is configured for adjusting length of the vertical supporter  2303 , which adjusts height of the seat  2301  off the floor. 
     Movable Seat: 
     In some embodiments, the seat  2301  is saddle shaped. Optionally the seat comprises one or more convex portions optionally positioned at a front portion of the seat  2301  (in front of the mounted user) and at a rear portion of the seat  2301  (behind the mounted user). In some embodiments, the seat  2301  includes one or more concave portions (such as, e.g., portions  460  at  FIG. 4A ). In some embodiments, the concave portions are positioned between the front portion and the rear portions, in vicinity of the thighs of a mounted user (e.g., lateral portions). 
     In some embodiments, the seat  2301  includes a central arch (such as, e.g., portion  410  at  FIG. 4A ) positioned between the convex portions and the concave portions. In some embodiments, the central arch comprises a saddle point. In some embodiments, each of the convex portions extends upwardly away from the arch. In some embodiments, each of the concave portions extends downwardly away from the arch. In some embodiments, the height of each of the convex portions, which is optionally the height above the central arch, does not exceed a height of the user&#39;s ilia bones. 
     Referring now to  FIGS. 24A-E  show schematic illustrations of a pelvis training system, according to some embodiments of the invention. 
       FIGS. 24A-E  show schematic illustrations of portions of a pelvis training system, with more details of a locking mechanism and how an example embodiment locking mechanism works. 
       FIG. 24A  is a cross sectional view from a left side of the pelvis training system, showing: a seat  2401 ; a flexible connector  2414 , connected at one end to the seat  2401 , and another end optionally shaped as a ring  2418  surrounding a vertical supporter  2416   2420 ; and a back strut  2408 , optionally connected to a locking prong  2412 . 
     In some embodiments, the vertical supporter  2416   2420  is adjustable in height, with a top portion  2416  of the vertical supporter  2416   2420  extending from a bottom portion  2420  of the vertical supporter. 
     In some embodiments, the height that the top portion  2416  of the vertical supporter  2416   2420  extends from a bottom portion  2420  of the vertical supporter into the flexible connector  2414 , or spring  2414 , enables setting a stiffness of the side-to-side and/or the forward-backward swaying of the seat  2401 . The more the top portion  2416  of the vertical supporter  2416   2420  extends into the flexible connector  2414 , the less length of the flexible connector  2414  is available for bending, the stiffer the resistance to swaying and/or the smaller the angular range available for the seat  2401  to bend from a central position. 
     In some embodiments, movement of the seat relative to a rest position is against resistance, optionally as provided by the flexible connector described herein, and the springs described herein. 
     In some embodiments, movement of the seat relative to a base of the seat is against resistance, as provided by the flexible connector described herein, and the springs described herein. 
     In some embodiments, the resistance is provided by an elastic component, such as a spring. Additional components which are optionally used for resistance to movement optionally include rubber bands, rubber bushings, flat springs, coil springs, and additional elastic components. 
     In some embodiments, the vertical supporter  2416   2420  comprises several components, such as a top portion  2416  movable up and down relative to a bottom portion  2420 , and an optional control, such as the control  2305  shown in  FIG. 23A  for adjusting an amount by which the top portion  2416  extends from the bottom portion  2420 . 
     In some embodiments, a control such as the control  2305  shown, for example, in  FIG. 23A , can serve to set a height that the top portion of the vertical supporter  2416  extends from a bottom portion  2420  of the vertical supporter into the flexible connector  2414 , or spring  2414 . 
     Optionally, the flexible connector  2414 , or spring  2414 , enables the seat  2401  to change angle, relative to the floor or to the device base, so the seat  2401  can move side-to-side and/or forward and back. In some embodiments a range of movement of the seat  2401  is optionally in a range from +10 degrees to −10 degrees. In some embodiments a range of movement of the seat  2401  is optionally in a range from +30 degrees to −30 degrees. In some embodiments a range of movement of the seat  2401  is optionally in a range from +45 degrees to −45 degrees. In some embodiments a range of movement of the seat  2401  is optionally in a range from +60 degrees to −60 degrees. 
     In some embodiments, not shown here but which can be understood based on the example described here, the vertical supporter  2416 , or at least the top portion of the vertical supporter  2416 , is a tube which surrounds the flexible connector  2414 . An amount by which the flexible connector  2414  extends from the surrounding vertical supporter  2416  optionally serves to adjust stiffness and/or the range of angular motion of the seat  2401 . 
     The above explanation referring to setting stiffness and/or angular range of swaying is provided here, with reference to  FIG. 24A , where the relevant components are clearly visible. However, the explanation is intended to apply to embodiments a shown in  FIGS. 20A-C ,  21 A-C,  22 A-C,  23 A-C and  24 A-E. 
     In some embodiments, the back strut  2408  is connected to an optional back support  242 , which optionally include a back cushion  2423 . In some embodiments, a height of the back cushion  2423  can be set by an optional control  2422 . 
     In some embodiments, the back strut  2408  is optionally connected to a bottom  2404  of the seat  2401  by a connecting strut  2406 . In some embodiments, the back strut  2408  may rotate relative to the seat  2401  base  2404 . In some embodiments, the rotation is optionally by a hinge such as the hinge  2014  shown, for example, in  FIG. 20A . 
     In some embodiments, a length by which the locking prong  2412  extends from the back strut  2408  is optionally adjustable, by using an optional control such as control  2410 . 
       FIGS. 24B and 24C  are side views from a left side of the pelvis training system, showing the locking mechanism in an unlocked position ( FIG. 24B ), and in a locked position ( FIG. 24C ), 
       FIGS. 24B and 24C  show: an optional top ring  2402  of the flexible connector  2414  attached to the bottom  2404  of the seat; an optional bottom ring  2418  of the flexible connector  2414 ; the flexible connector  2414  surrounding a top portion of the vertical supporter  2416 ; a bottom portion  2420  of the vertical supporter; the connecting strut  2406 , the back strut  2408 ; the locking prong  2412 ; and the optional locking prong adjustment control  2410 . 
       FIG. 24B  shows the back strut  2408  NOT forcing the locking prong  2412  against the bottom ring  2418  of the flexible connector  2414 , which potentially enables a user to sway back-and-forth and/or side-to-side. 
       FIG. 24C  shows the back strut  2408  forcing the locking prong  2412  against the bottom ring  2418  of the flexible connector  2414 , which potentially prevents a user from swaying back-and-forth and/or side-to-side. 
     In some embodiments, a user (not shown in  FIG. 24C ) optionally leans back on the seat, forcing the locking prong  2412  against the bottom ring  2418  of the flexible connector  2414 , which potentially enables a user to sway back-and-forth and/or side-to-side. 
       FIGS. 24C and 24D  are isometric views from a left side of the pelvis training system, showing the locking mechanism in an unlocked position ( FIG. 24D ), and in a locked position ( FIG. 24E ), 
       FIGS. 24D and 24E  show: an optional top ring  2402  of the flexible connector  2414  attached to the bottom  2404  of the seat; an optional bottom ring  2418  of the flexible connector  2414 ; the flexible connector  2414  surrounding a top portion of the vertical supporter  2416 ; a bottom portion  2420  of the vertical supporter; the connecting strut  2406 , and the locking prong  2412 . 
       FIG. 24D  shows the locking prong  2412  NOT pressing against the bottom ring  2418  of the flexible connector  2414 , which potentially enables a user to sway back-and-forth and/or side-to-side. 
       FIG. 24E  shows the locking prong  2412  pressing against the bottom ring  2418  of the flexible connector  2414 , which potentially locks, NOT enables a user to sway back-and-forth and/or side-to-side. 
     In some embodiments, a user (not shown in  FIG. 24C ) optionally leans back on the seat, forcing the locking prong  2412  against the bottom ring  2418  of the flexible connector  2414 , which potentially enables a user to sway back-and-forth and/or side-to-side. 
     Referring now to  FIG. 25  shows a schematic flow chart illustration of a method of pausing exercise on a pelvis exercising system according to some embodiments of the invention. 
     The method of  FIG. 25  includes: 
     exercising on a pelvis exercising system ( 2502 ); and 
     locking degrees of freedom of the system ( 2504 ). 
     Referring now to  FIG. 26  shows a schematic flow chart illustration of a method of enabling a user to become accustomed to using a pelvis exercising system according to some embodiments of the invention. 
     The method of  FIG. 26  includes: 
     providing a pelvis exercising system ( 2602 ); and 
     providing a locking mechanism for a user to lock degrees of freedom of the system ( 2604 ). 
     Referring now to  FIG. 27  shows a schematic flow chart illustration of a method of locking a wobbly seat according to some embodiments of the invention. 
     The method of  FIG. 27  includes: 
     providing a wobbly seat ( 2702 ); and 
     providing a locking mechanism for a user to lock degrees of freedom of the wobbly seat ( 2704 ). 
     Referring now to  FIGS. 28A-D  show a schematic illustration of locking mechanisms for locking a wobbly seat according to some embodiments of the invention. 
       FIGS. 28A-C  show cross-sectional top views of locking mechanisms, and  FIG. 28D  shows a side view of a locking mechanism. 
       FIGS. 28A-D  show a vertical support  2803  and a back strut  2805 , with various locking mechanisms  2807   2808   2809   2810  or various locking prongs  2807   2808   2809   2810 . 
       FIG. 28A  shows a semi-circular-shaped locking mechanism  2807  or locking prong  2807 , for fitting around the vertical support  2803 . 
       FIG. 28B  shows a rectangular-shaped locking mechanism  2808  or locking prong  2808 , for fitting around the vertical support  2803 . 
       FIG. 28C  shows a pin-shaped locking mechanism  2809  or locking prong  2809 , for fitting around the vertical support  2803 . 
       FIG. 28D  shows a locking mechanism of prong, by way of a non-limiting example as shown in  FIGS. 28A-C , and shows the back strut  2805  pressing against the vertical support  2803 . In some embodiments, when the back strut  2805  presses against the vertical support  2803 , a seat cannot move backward any more (looking at other drawings herein can show this movement). In some embodiments, when the back strut  2805  presses against the vertical support  2803 , the seat cannot sway side-to-side any more (looking at other drawings herein can show this movement). 
     In some embodiments, pushing the back strut  2805  against the vertical support  2803  potentially closes a closed shape formed by the seat (not shown), the back strut  2805  and the vertical support  2803 . 
     In some embodiments, the closed shape is a triangle. 
     In some embodiments, the closed shape is formed by the flexible support shown in  FIGS. 20A-C ,  21 A-C,  22 A-C,  23 A-C,  24 A-D; the vertical support  2893 ; the back strut  2805  and the seat. 
     It is noted that the vertical support  2803  does not necessarily have to have a circular cross-section. The vertical support  2803  may have a rectangular, square, triangular or other cross-sectional shape. 
     Referring now to  FIG. 29  shows a schematic illustration of controlling movement using data from sensors in a pelvis exercising system according to some embodiments of the invention. 
       FIG. 29  is intended to illustrate using sensor data which is associated with movement of a seat to electronically control a display or a device, similarly to a mouse controlling a display or a device. 
       FIG. 29  shows a display  2902 , including a first portion  2904 , which displays a path  2908  indicating a position of a seat, relative to some center point, over the last N seconds of movement. The path  2908  fades out the older the position is, showing the last position brightest, and gradually fading away. 
     In some embodiments the display  2902  optionally includes on-screen controls  906  for recording or playing back an exercise session. 
     It is noted that  FIG. 29  is a non-limiting example of the aspect described above, relating to using sensors to measure movement of the seat along one or more of the degrees of freedom which the seat can move, and using values thus measured in a computer application. 
     Some uses for the sensor data values include: 
     a) controlling movement of a cursor on a display. 
     b) controlling movement of a game control on a display, potentially enabling playing a game. 
     It is noted that the above-mentioned four degrees of freedom potentially enable controlling a display in one, two, three or four dimensions (by way of a non-limiting example including time as a dimension). 
     By way of a non-limiting example, playing Pong, which requires controlling movement of a paddle along one dimension, can be done by associating side-to-side movement, or forward and backward movement, to movement of a paddle used in the game. 
     By way of a non-limiting example, controlling a kayak simulation game, for example by rotating the seat to control the direction of the simulated kayak, and leaning sideways to control a weight of a simulated paddler in the simulated kayak. 
     By way of another non-limiting example, controlling a snow ski simulation game, for example by rotating the seat to control the direction of the simulated skis; leaning sideways to control a sideways leaning of a simulated skier on the simulated skis; leaning forward or backward to control forward and backward lean, and moving, or bouncing, up and down on the seat to simulate jumping or skiing over moguls. 
     c) controlling movement of a device movement in at least one, two, three or four degrees of freedom. 
     d) tracking a user&#39;s movement on the seat. Such tracking can sense changes in a user&#39;s posture. In some embodiments, a display displays one or more measures of the user&#39;s posture to the user. In some embodiments, the user is additionally displayed desired values, and asked to perform exercise on the seat so as to reach the desired values. By way of a non-limiting example, a user may be present with lines on the first portion  2904  of the display  2902 , and instructed to move the seat to have the path  2908  reach those lines, or reach those lines N times in a period of time, as an exercise. 
     In some embodiments, an office manager or a store manager can initiate an exercise routine for workers sitting down, such as office workers, cashiers, and so on, and provide appropriate seat pelvis exercising systems and exercise programs for the workers. 
     In some embodiments, a physiotherapist can provide an exercise routine for a patient on a seat pelvis exercising systems, and optionally track results using the data values from the sensor(s). 
     General: 
     The terms “comprises”, “comprising”, “includes”, “including”, “has”, “having” and their conjugates mean “including but not limited to”. 
     The term “consisting of” means “including and limited to”. 
     The term “consisting essentially of” means that the composition, method or structure may include additional ingredients, steps and/or parts, but only if the additional ingredients, steps and/or parts do not materially alter the basic and novel characteristics of the claimed composition, method or structure. 
     As used herein, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a compound” or “at least one compound” may include a plurality of compounds, including mixtures thereof. 
     Throughout this application, embodiments of this invention may be presented with reference to a range format. It should be understood that the description in range format is merely for convenience and brevity and should not be construed as an inflexible limitation on the scope of the invention. Accordingly, the description of a range should be considered to have specifically disclosed all the possible subranges as well as individual numerical values within that range. For example, description of a range such as “from 1 to 6” should be considered to have specifically disclosed subranges such as “from 1 to 3”, “from 1 to 4”, “from 1 to 5”, “from 2 to 4”, “from 2 to 6”, “from 3 to 6”, etc.; as well as individual numbers within that range, for example, 1, 2, 3, 4, 5, and 6. This applies regardless of the breadth of the range. 
     Whenever a numerical range is indicated herein (for example “10-15”, “10 to 15”, or any pair of numbers linked by these another such range indication), it is meant to include any number (fractional or integral) within the indicated range limits, including the range limits, unless the context clearly dictates otherwise. The phrases “range/ranging/ranges between” a first indicate number and a second indicate number and “range/ranging/ranges from” a first indicate number “to”, “up to”, “until” or “through” (or another such range-indicating term) a second indicate number are used herein interchangeably and are meant to include the first and second indicated numbers and all the fractional and integral numbers there between. 
     Unless otherwise indicated, numbers used herein and any number ranges based thereon are approximations within the accuracy of reasonable measurement and rounding errors as understood by persons skilled in the art. 
     It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements. 
     Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the spirit and broad scope of the appended claims. 
     All publications, patents and patent applications mentioned in this specification are herein incorporated in their entirety by reference into the specification, to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated herein by reference. In addition, citation or identification of any reference in this application shall not be construed as an admission that such reference is available as prior art to the present invention. To the extent that section headings are used, they should not be construed as necessarily limiting. 
     In addition, any priority document(s) of this application is/are hereby incorporated herein by reference in its/their entirety.