Shoe with torsion assembly

Abstract

A shoe includes an upper, a sole structure attached to the upper, and a torsion assembly. The torsion assembly includes a torsion member coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end, an adjustable medial linkage having a first end connected to the medial end of the torsion member and a distal end connected to the shoe, and an adjustable lateral linkage having a first end connected to the lateral end of the torsion member and a distal end connected to the shoe. Movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in an initial rotational direction, the torsion member providing a resisting force in an opposite rotational direction to restore the medial linkage and the lateral linkage toward the equilibrium position and provide stability for the shoe.

Description

TECHNICAL FIELD

[0001] Embodiments relate to a shoe with a torsion assembly, such as for enhancing stability of the shoe.BACKGROUND

[0002] Pronation and supination are natural movements of the foot during running and other activities, but overpronation or excessive supination can lead to instability and injury. Pronation occurs when the foot rolls inward after landing, allowing the arch to flatten. If the foot rolls inward too much, termed overpronation, it can cause excessive strain on muscles, tendons, and ligaments, especially on the medial side of the foot and leg. Supination occurs when the foot rolls outward as it pushes off. In instances of excessive supination, too much stress is placed on the lateral structures of the foot and lower leg. Both overpronation and excessive supination can also disrupt natural gait and alignment, leading to imbalances and joint strain throughout the body.

[0003] In running shoes, midsole construction is trending toward the use of taller, softer foams. Softer foams are also being used in shoes associated with lateral motion sports, such as soccer and basketball. Higher midsole stack heights offer benefits to running and movement economy. However, such construction also allows for increasing deformation, which may be as much as 50% in modern foams (or even higher in 3D printed lattices), leading to instability such as overpronation or excessive supination. In addition to increasing the likelihood of injury, instability leads to compromises in shoe development between weight, stack, foam softness, and stability.SUMMARY

[0004] In one or more embodiments, a shoe includes an upper, a sole structure attached to the upper, and a torsion assembly. The torsion assembly includes a torsion member coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end, an adjustable medial linkage having a first end connected to the medial end of the torsion member and a distal end connected to the shoe, and an adjustable lateral linkage having a first end connected to the lateral end of the torsion member and a distal end connected to the shoe. Movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in an initial rotational direction, the torsion member providing a resisting force in an opposite rotational direction to restore the medial linkage and the lateral linkage toward the equilibrium position and provide stability for the shoe.

[0005] In one or more embodiments, the medial linkage includes a medial arm and a medial post, the medial arm including the first end of the medial linkage and the medial post including the distal end of the medial linkage, the medial post having a proximal end rotatably connected to a second end of the medial arm, and the lateral linkage includes a lateral arm and a lateral post, the lateral arm including the first end of the lateral linkage and the lateral post including the distal end of the lateral linkage, the lateral post having a proximal end rotatably connected to a second end of the lateral arm.

[0006] In one or more embodiments, at least one anchor may couple the torsion member to the shoe. In one or more embodiments, the torsion member, the medial linkage, and the lateral linkage may be disposed external to the shoe. In one or more embodiments, the torsion member may be coupled to the upper. In one or more embodiments, the torsion member may be at least partially disposed through the sole structure. In one or more embodiments, the distal end of the medial linkage and the distal end of the lateral linkage may be mounted to the sole structure. In one or more embodiments, the medial linkage and the lateral linkage may be mounted to a brace encircling the upper.

[0007] In one or more embodiments, the torsion member may be removable from the medial linkage and the lateral linkage. In one or more embodiments, the medial linkage may have a different stiffness than the lateral linkage. In one or more embodiments, the torsion member may include a rate-dependent material. In one or more embodiments, the torsion member may have an asymmetric stiffness to bias the equilibrium position toward the medial linkage or the lateral linkage. In one or more embodiments, a limiter sheath may at least partially surround the torsion member for limiting rotation of the torsion member. In one or more embodiments, an inertial measurement unit (IMU) may provide adaptive stiffness of the torsion member.

[0008] In one or more embodiments, a torsion assembly for a shoe includes a torsion member configured to be coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end. The torsion assembly further includes a medial linkage including a medial arm and a medial post, the medial arm having a first end connected to the medial end of the torsion member, the medial post having a proximal end rotatably connected to a second end of the medial arm and a distal end configured to be connected to the shoe. The torsion assembly further includes a lateral linkage including a lateral arm and a lateral post, the lateral arm having a first end connected to the lateral end of the torsion member, the lateral post having a proximal end rotatably connected to a second end of the lateral arm and a distal end configured to be connected to the shoe. Movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in an initial rotational direction, the torsion member providing a resisting force in an opposite rotational direction to restore the medial linkage and the lateral linkage toward the equilibrium position and provide stability for the shoe.

[0009] In one or more embodiments, a torsion assembly for a shoe includes a torsion member configured to be coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end. The torsion assembly further includes a medial linkage including a medial arm and a medial post, the medial arm having a first end connected to the medial end of the torsion member, the medial post having a proximal end rotatably connected to a second end of the medial arm and a distal end configured to be connected to the shoe. The torsion assembly further includes a lateral linkage including a lateral arm and a lateral post, the lateral arm having a first end connected to the lateral end of the torsion member, the lateral post having a proximal end rotatably connected to a second end of the lateral arm and a distal end configured to be connected to the shoe. Movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in a rotational direction, the torsion member providing an augmenting force in the rotational direction to bias the medial linkage and the lateral linkage away from the equilibrium position and provide asymmetric stability of the shoe.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] FIG. 1 is a perspective view of a torsion assembly including a torsion member, a medial linkage, and a lateral linkage according to one or more embodiments;

[0011] FIG. 2 is a rear perspective view of a shoe with a torsion assembly mounted thereto according to one or more embodiments;

[0012] FIG. 3 is a rear view of a shoe with the torsion assembly in an equilibrium position according to one or more embodiments;

[0013] FIG. 4 is a side view of a shoe with the torsion assembly in an equilibrium position according to one or more embodiments;

[0014] FIG. 5 is a side view of a shoe with the lateral linkage of the torsion assembly moved away from the equilibrium position according to one or more embodiments;

[0015] FIG. 6 is a rear view of a shoe with the medial linkage of the torsion assembly moved away from the equilibrium position, causing a resisting force of the torsion member indicated by the arrow according to one or more embodiments;

[0016] FIG. 7 is a rear view of a shoe with the lateral linkage of the torsion assembly moved away from the equilibrium position, causing a resisting force of the torsion member indicated by the arrow according to one or more embodiments;

[0017] FIG. 8 is a front perspective view of a shoe illustrating possible placements of the torsion assembly with the torsion member disposed within a cavity in the sole structure and the lateral linkage anchored in the sole structure according to one or more embodiments;

[0018] FIG. 9 is a side view of a shoe illustrating a placement of the torsion assembly with the torsion member disposed with a cavity in the sole structure and the lateral linkage anchored to the upper according to one or more embodiments;

[0019] FIG. 10 is a top view of a shoe illustrating a placement of the torsion assembly with the torsion member disposed adjacent to the laces of the upper according to one or more embodiments;

[0020] FIG. 11 is a perspective view of a torsion assembly with a limiter system according to one or more embodiments;

[0021] FIG. 12 is a cross-sectional view of the limiter sheath and torsion member of FIG. 11; and

[0022] FIG. 13 is a perspective view of a torsion assembly with an inertial measurement unit (IMU) according to one or more embodiments.DETAILED DESCRIPTION

[0023] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0024] The disclosed embodiments provide a torsion assembly for a shoe which improves and controls medial-lateral stability without affecting the vertical compliance or deformation of the midsole or limiting the maximum stack height of the midsole. The torsion assembly further allows tuning of the roll stiffness of a shoe, and facilitates midsole design independent from its vertical stiffness. As a result of the increase in medial-lateral stability, the torsion assembly can prevent transverse shear of the midsole while allowing longitudinal shear.

[0025] With reference first to FIGS. 1-2, a shoe 100 with a torsion assembly 200 is illustrated according to one or more embodiments. As is known in the art, footwear such as the shoe 100 depicted herein typically includes an upper 102 and a sole structure 104. The upper 102 secures the shoe 100 to the wearer’s foot and may be made of synthetic, knit, fabric and / or leather materials to comfortably cover the wearer’s foot and provide protection and ventilation. The sole structure 104 is the part of the shoe 100 disposed below the wearer’s foot and may be constructed of several layers such as an insole (not shown), a midsole 106, and an outsole 108 along a bottom surface of the midsole 106. The midsole 106 extends from a heel region 110, to a midfoot region 112, to a forefoot region 114 of the shoe 100 to provide support to the wearer’s foot. The outsole 108 forms the outer exposed part of the sole structure 104 that comes into contact with the ground or other support surface, may be constructed from materials such as rubber or thermoplastic polyurethane (TPU), and typically includes a tread design. The upper 102 may be attached to the sole structure 104, such as to an upper surface of the midsole 106. The midsole 106 may include foam (e.g. ethylene vinyl acetate (EVA)), 3D printed material (e.g., TPU), or other supportive and resilient material such as for cushioning, energy absorption, and ground reaction force attenuation. While several embodiments illustrated herein depict the sole structure 104 as including a midsole 106, it is understood that in other embodiments the sole structure 104 may not include this layer.

[0026] With continuing reference to FIGS. 1-2, the torsion assembly 200 includes a torsion member 202 coupled to the shoe 100 in a medial-lateral orientation along a medial-lateral axis 116. In one or more embodiments, the medial-lateral axis 116 may be generally transverse to a longitudinal axis 118 of the shoe 100, however, the medial-lateral orientation as described herein is meant to encompass any orientation of the torsion member 202 intersecting the longitudinal axis 118 that spans between a medial side 120 and a lateral side 122 of the shoe 100.

[0027] The torsion member 202 has a medial end 204 and a lateral end 206, and in one or more embodiments may comprise a torsion spring. Unlike compression or extension springs which expand or compress along their length, a torsion spring operates by rotating about its central axis (medial-lateral axis 116). The torsion member 202 may alternatively comprise a torsion bar. In one or more embodiments, the torsion member 202 may be generally cylindrical, although it is not limited to this configuration. For example, the torsion member 202 could alternatively be curved or have an inverted U shape. The torsion member 202 may be sized to span a distance between the medial side 120 and the lateral side 122 of the shoe 100, but could have any suitable length or thickness. The torsion member 202 may be constructed from metallic material (e.g., steel or titanium), a plastic material (e.g., polyamide), or any other material suitable to store and release energy created due to a rotational force on the torsion member 202, as described further below.

[0028] The torsion assembly 200 further includes an adjustable medial linkage 208 having a first end 210 connected to the medial end 204 of the torsion member 202 and a distal end 212 connected to the shoe 100, and an adjustable lateral linkage 214 having a first end 216 connected to the lateral end 206 of the torsion member and a distal end 218 connected to the shoe 100. In one or more embodiments, the first end 210 is rigidly connected to the medial end 204 and the first end 216 is rigidly connected to the lateral end 206. The medial linkage 208 and the lateral linkage 214 may be constructed from a metallic, plastic, or any other suitable material, and the rigid connection of the torsion member 202 to the first end 210 of the medial linkage 208 and the first end 216 of the lateral linkage 214 may be accomplished, for example, via welding, fastening, or otherwise connecting the components together such that relative rotation between them is prevented. In one or more embodiments, fixed mounting between these components may be accomplished with the torsion member 202 being integrally formed with the first ends 210, 216 of the medial linkage 208 and the lateral linkage 214. In another embodiment, the torsion member 202 may be removably mounted to the medial linkage 208 and the lateral linkage 214, as described further below.

[0029] In one or more embodiments, the medial linkage 208 includes a medial arm 220 and a medial post 222. The medial arm 220 includes the first end 210 of the medial linkage 208 and the medial post 222 includes the distal end 212 of the medial linkage 208. The medial post 222 has a proximal end 224 rotatably connected to a second end 226 of the medial arm 220. Correspondingly, the lateral linkage 214 includes a lateral arm 228 and a lateral post 230. The lateral arm 228 includes the first end 216 of the lateral linkage 214 and the lateral post 230 includes the distal end 218 of the lateral linkage 214. The lateral post 230 has a proximal end 232 rotatably connected to a second end 234 of the lateral arm 228.

[0030] Referring again to FIGS. 1-2, the medial arm 220 and the lateral arm 228 may be generally planar with rounded first ends 210, 216 and second ends 226, 234. In addition, the medial arm 220 and the lateral arm 228 may be constructed such that the first ends 210, 216 have a greater width than the second ends 226, 234 as illustrated, although it is understood that the medial arm 220 and the lateral arm 228 may have any suitable shape. In one or more embodiments, the medial post 222 and the lateral post 230 may be generally cylindrical in shape, with the proximal ends 224, 232 including spaced support members 236 which receive the second ends 226, 234 therebetween, but are not limited to this configuration.

[0031] The rotatable connection between the proximal ends 224, 232 of the medial post 222 and the lateral post 230 and the second ends 226, 234 of the medial arm 220 and the lateral arm 228, respectively, can be embodied as a hinge joint or pin joint with a central pin 238 through each second end 226, 234 and received by the support members 236 at each proximal end 224, 232. This pin joint allows for rotation of the medial arm 220 and the lateral arm 228 about the joint axis 240 with one degree of freedom. The distal ends 212, 218 of the medial linkage 208 and the lateral linkage 214 (i.e. the medial post 222 and the lateral post 230) are mounted to the shoe 100 thereby defining a constant joint axis 240 of the pin joint, where the medial arm 220 and the lateral arm 228 are free to rotate about the joint axis 240 as described further below. Of course, the pin joint is not limited to this structure, and other hinge joint or rotatable configurations are also contemplated. Other configurations of the medial linkage 208 and the lateral linkage 214 are fully contemplated such as, but not limited to, linkages 208, 214 comprising a compliant mechanism that achieves force transmission through elastic deformation.

[0032] In one or more embodiments, the distal end 212 of the medial linkage 208 and the distal end 218 of the lateral linkage 214 are rigidly mounted to the sole structure 104. Alternatively, the distal end 212 of the medial linkage 208 and the distal end 218 of the lateral linkage 214 may be rotatably mounted to the sole structure 104. In the example shown in FIGS. 1-3, the distal ends 212, 218 each include or are mounted to a plate 242. The plates 242 may generally extend inward from the medial side 120 and the lateral side 122 of the shoe 100 to be received within and secured to the sole structure 104, such as within the midsole 106, within the outsole 108, or between the midsole 106 and the outsole 108. While the plates 242 are depicted herein to be generally square, it is understood that the plates 242 are not limited to this shape and may have any configuration suitable for securing the medial post 222 and the lateral post 230 to the sole structure 104. In one non-limiting example, the plates 242 may be elongated to span from the heel region 110 to the midfoot region 112, from the midfoot region 112 to the forefoot region 114, or from the heel region 110 to the forefoot region 114. The plates 242 may be separate as shown, or may be connected together or have a unitary configuration within the sole structure 104.

[0033] As illustrated in FIGS. 2 and 3, in one non-limiting embodiment, the torsion member 202, the medial linkage 208, and the lateral linkage 214 are all disposed external to the shoe 100, such as with the medial linkage 208 visible on the medial side 120 of the shoe 100, the lateral linkage 214 visible on the lateral side 122 of the shoe 100, and the torsion member 202 visible on the back or heel region 110 of the shoe 100. The torsion member 202 may be coupled to the shoe 100, such as to the upper 102, although other locations are also contemplated. As shown in FIGS. 2 and 3, at least one anchor 244 may be provided for coupling the torsion member 202 to the shoe 100. The one or more anchors 244 may have a generally C-shaped configuration, for example, with a radius larger than a radius of the torsion member 202 so as to not restrict twisting of the torsion member 202 under rotational force as described further below.

[0034] The torsion member 202 stores and releases mechanical energy when twisted or rotated. It resists twisting forces (torsion) and attempts to return to its original equilibrium position when the applied force is removed. When the sole structure 104, namely the midsole 106, compresses evenly or symmetrically between the medial side 120 and the lateral side 122, the torsion assembly 200 essentially rotates as a unit, with the medial linkage 208 and the lateral linkage 214 having generally equivalent rotations about the joint axis 240. FIG. 3 is a rear view and FIG. 4 is a side view of a shoe 100 with the torsion assembly 200 in an equilibrium position according to one or more embodiments.

[0035] It is understood that the equilibrium position is not limited to a particular angular orientation of the torsion member 202, the medial linkage 208, and the lateral linkage 214, and that the equilibrium position may also be interpreted as an original position of the torsion assembly 200 prior to the applied force. Furthermore, while certain figures only depict a medial side 120 or lateral side 122, it is understood that the description and features described herein for one of the medial side 120 or the lateral side 122 may be equally applicable to the other side.

[0036] As the shoe 100 undergoes forces compressing the midsole 106 unevenly or asymmetrically on the medial side 120 (e.g. pronation or overpronation) or the lateral side 122 (e.g. supination or excessive supination), the medial side 120 or the lateral side 122 moves up or down, rotating the medial linkage 208 and the lateral linkage 214, and thus imparting a rotational force (torque) on the torsion member 202. This rotation causes the torsion member 202 to twist, and the torsion member 202 resists this motion by storing potential energy in the form of torsional stress. FIG. 5 is a side view of a shoe 100 with the lateral linkage 214 rotated away from an equilibrium position due to compression on the lateral side 122 (as indicated by the downward arrow) according to one or more embodiments.

[0037] In other words, movement of the medial linkage 208 or the lateral linkage 214 away from an equilibrium position due to a compression force twists the torsion member 202 in an initial rotational direction about the medial-lateral axis 116. The torsion member 202 provides a resisting force (i.e. release of stored energy) in an opposite rotational direction about the medial-lateral axis 116 to restore the medial linkage 208 and the lateral linkage 214 toward the equilibrium position and provide stability for the shoe 100. FIG. 6 is a rear view of a shoe 100 with the medial linkage 208 moved away from the equilibrium position, causing a resisting force of the torsion member 202 indicated by the arrow according to one or more embodiments. FIG. 7 is a rear view of a shoe 100 with the lateral linkage 214 moved away from the equilibrium position, causing a resisting force of the torsion member indicated by the arrow according to one or more embodiments.

[0038] Accordingly, the torsion assembly 200 provides medial-lateral roll stability of the shoe 100 without affecting the vertical compliance or compression of the midsole 106, thus helping to solve the existing compromise between the cushioning of a midsole 106 and its stability in a shoe 100. The torsion assembly 200 functions to bias the midsole 106 and shoe 100 toward an equilibrium position which may keep the compression on each side of the midsole 106 as even as possible. This maintains more complete coverage of the shoe 100 (i.e., outsole 108) on a support surface, and allows for higher stack heights of the midsole 106 and / or a midsole 106 which is softer in compression without compromising medial-lateral stability.

[0039] While the torsion member 202 is described above as being mounted in the heel region 110, the torsion member 202 is not limited to this configuration and may be mounted in other locations on or within the shoe 100. In one example, the torsion member 202 may be at least partially disposed through the sole structure 104 of the shoe 100, such as within a cavity 124 wherein the torsion member 202 is free to twist about the medial-lateral axis 116 in response to an applied force. FIG. 8 is a front perspective view of a shoe 100 illustrating possible placements of the torsion assembly 200 with the torsion member 202 disposed within a cavity 124 in the midsole 106 and the medial linkage 208 and the lateral linkage 214 anchored in the midsole 106 according to one or more embodiments. In these examples, the cavity 124 and the torsion member 202 may be disposed in a heel region 110 or a forefoot region 114 as shown. However, the cavity 124 and the torsion member 202 may be located at any region of the midsole 106 or outsole 108. In the example of FIG. 8, the medial linkage 208 and the lateral linkage 214 are each disposed external to the shoe 100. In one or more embodiments, at least a portion of the torsion member 202 may extend beyond the cavity 124 to facilitate accessibility of the torsion member 202 if necessary.

[0040] As illustrated in FIG. 8, the shoe 100 may include more than one torsion assembly 200. In such an embodiment, each torsion assembly 200 could remain separate and independent, or the torsion assemblies 200 could be mechanically connected. For example, the medial linkage 208 of a first torsion assembly 200 could be connected to a lateral linkage 214 of a second torsion assembly 200 and vice versa for a cross-linked stability effect. The medial linkage 208 and the lateral linkage 214 may have any positioning with respect to each other another along the sole structure 104, and are not limited to any particular medial-lateral axis 116.

[0041] Instead of being anchored to the sole structure 104 via plates 242, the medial linkage 208 and the lateral linkage 214 could be anchored to another part of the shoe 100. FIG. 9 is a side view of a shoe 100 illustrating a placement of the torsion assembly 200 with the torsion member 202 disposed with a cavity 124 in the midsole 106 and the medial linkage 208 and the lateral linkage 214 anchored to the upper 102 according to one or more embodiments. In one example, the medial linkage 208 and the lateral linkage 214 are mounted to a brace 126 encircling the upper 102 (e.g. at the collar). In this example, the medial post 222 and the lateral post 230 are connected to the brace 126, which may control eversion and inversion at the wearer’s ankle without restricting forward and backward (longitudinal) movement. One application of this configuration could be a high top basketball shoe, although other shoe types are also contemplated.

[0042] FIG. 10 is a top view of a shoe 100 illustrating another placement of the torsion assembly 200 with the torsion member 202 disposed adjacent to the laces 128 of the upper 102 according to one or more embodiments. While the torsion member 202 is shown in this figure as being disposed over the top of the laces 128, this configuration is not intended to be limiting, as the torsion member 202 could also connect to the medial linkage 208 and the lateral linkage 214 through the laces 128, through the material of the upper 102, through the eyelets 130, closer to the heel region 110 (e.g. near the ankle or collar), closer to the forefoot region 114, or other configurations. Such an embodiment might be advantageous, for example, to counteract toe-up issues in sports like basketball and the instability caused by lateral cutting movements.

[0043] Turning now to FIG. 11, a perspective view of a torsion assembly 200 with a limiter system 246 for limiting rotation of the torsion member 202 is illustrated. In one or more embodiments, the limiter system 246 may include a stop member 248 extending outwardly from the torsion member 202, with a limiter sheath 250 at least partially surrounding the torsion member 202 and spaced from the stop member 248. FIG. 12 is a cross-sectional view of the torsion member 202, the limiter sheath 250, and the stop member 248 of FIG. 11. Both the stop member 248 and the limiter sheath 250 may be integrally formed with or connected to the torsion member 202. It is understood that the dimensions of the stop member 248 and the limiter sheath 250 are merely exemplary, and are not limited to the embodiment illustrated herein.

[0044] The limiter system 246 functions to define the range of angular rotation of the torsion assembly 200. The torsion member 202 is free to rotate or twist in response to an applied force as described above until the stop member 248 engages the limiter sheath 250. While the limiter system 246 could be configured to allow a symmetrical angular range for roll on the medial side 120 and the lateral side 122, it could alternatively be configured to create a range of angular rotation asymmetrically distributed between the medial side 120 and the lateral side 122. An example use case for an asymmetrical angular range created by the limiter system 246 may include track running wherein a greater angular rotation range on the medial side 120 compared with the lateral side 122 could be beneficial.

[0045] In embodiments where the shoe 100 includes more than one torsion assembly 200, limiter sheaths 250 creating different ranges of angular rotation could be utilized. For example, a limiter system 246 on a torsion assembly 200 disposed in the heel region 110 may be configured with a smaller angular range than a limiter system 246 on a torsion assembly 200 disposed in the forefoot region 114. Built-in or removable limiter sheaths 250 could be utilized to allow for customization of the possible angular range of the torsion assembly 200 for different individuals or different sports / activities. While the limiter system 246 is shown and described herein as being associated with the torsion member 202, a limiter system 246 could alternatively be coupled to the medial linkage 208 and / or the lateral linkage 214 to limit angular rotation of the torsion assembly 200.

[0046] In the embodiments described with respect to FIGS. 6 and 7, the torsion assembly 200 functions to attempt to restore an equilibrium position of the shoe 100. However, in some instances, it may be desirable for the torsion assembly 200 to amplify the roll due to an applied force or accentuate the force created by an angled surface instead of limiting it. In this embodiment, movement of the medial linkage 208 or the lateral linkage 214 away from an equilibrium position twists the torsion member 202 in a rotational direction, with the torsion member 202 providing an augmenting force in the rotational direction to bias the medial linkage 208 and the lateral linkage 214 away from the equilibrium position and provide asymmetric stability of the shoe 100.

[0047] Similar to the asymmetrical limiter system 246 discussed above, this embodiment of the torsion assembly 200 could be advantageous in situations where banking (e.g. track running) or other asymmetric movements are performed. Asymmetry of the torsion assembly 200 could be achieved, for example, by having a stiffer lateral linkage 214 compared to the medial linkage 208 or vice versa, such as by using stiffer materials, thicker / stiffer geometry, or positioning one of the medial linkage 208 or the lateral linkage 214 closer to the shoe 100 compared with the other linkage 208, 214 to create different lever arms for the medial linkage 208 and the lateral linkage 214.

[0048] Asymmetry in the torsion assembly 200 could also be accomplished by having a torsion member 202 that it is stiffer or more compliant toward one of the medial side 120 or the lateral side 122, that biases the equilibrium position toward the medial linkage 208 or the lateral linkage 214 and limits one of pronation or supination more than the other, or other methods. In one example, the torsion member 202 could include cuts or 3D printed lattice structures which act to bias stiffness of the torsion member 202 toward one of the medial side 120 or lateral side 122.

[0049] In general, the torsion member 202 may be progressive in nature, providing a greater resistance to rotation with increasing applied force. The torsion member 202 could also comprise a rate-dependent material. For example, the torsion member 202 could be constructed from a non-Newtonian fluid or foam inside a textile braided structure, wherein as the braid twists, it thins, creating a nonlinear response. If the sole structure 104 is subjected to a fast, unbalanced load, the non-Newtonian fluid will respond with greater stiffness compared to the response to a relatively slower load.

[0050] As indicated above, in one or more embodiments the torsion member 202 may be removable from the medial linkage 208 and the lateral linkage 214. The torsion member 202 could be disconnected and replaced with a different torsion member 202 with the same or different characteristics (e.g., stiffness, symmetric vs. asymmetric, etc.) or geometry (e.g., replacing a straight torsion member 202 with a curved torsion member 202), allowing the torsion assembly 200 to be customizable for the particular wearer or activity. The shoe 100 could also be used with the torsion member 202 attached for certain activities and with the torsion member 202 removed for other activities. In one or more embodiments, disconnecting of the torsion member 202 from the shoe 100 could be achieved manually. For example, the torsion member 202 could be removably mounted to the medial linkage 208 and the lateral linkage 214 via fasteners, magnets, press fit / interference fit connections, or other mechanisms.

[0051] FIG. 13 is a perspective view of a torsion assembly 200 with an inertial measurement unit (IMU) 252 according to one or more embodiments. The IMU 252 (depicted schematically) is capable of measuring at least one of the orientation, angular velocity, and linear acceleration of the torsion assembly 200 and / or the shoe 100 to electronically adjust or tune the stiffness of the torsion member 202. The IMU 252 may be operably connected to (e.g., in electrical communication with) the torsion member 202 to provide electronic control of the stiffness of the torsion member 202, including the option of zero stiffness (electronic disconnect of the torsion member 202). The IMU 252 may be mounted anywhere on or within the shoe 100, and the IMU 252 may drive a motor 254 engaged with the torsion member 202 and operable to control the torsion member 202, wherein the IMU 252 may automatically adjust the characteristics of the torsion member 202 or allow for user input or preference. With information from the IMU 252, such as gait measurements or about where the shoe 100 is in space, the stiffness of the torsion member 202 could be dynamically adjusted, such as before heel strike on a support surface or after push off. The stiffness of the torsion member 202 could also be adjusted via the IMU 252 depending on the type of surface engaged or the type of activity.

[0052] With embodiments of the shoe 100 and torsion assembly 200 disclosed herein, vertical compliance and medial-lateral stability of the shoe 100 are no longer solely determined by the material and shape of the midsole 106. The torsion assembly 200 disclosed herein provides the ability to use softer midsoles and / or higher stack height midsoles, since the torsion assembly 200 increases medial-lateral stability without having an effect on compression. The torsion assembly 200 offers more direct control, tuning, and customization of medial-lateral roll, and is beneficial for both lateral and linear activities.

[0053] While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.

Claims

1. A shoe comprising:an upper;a sole structure attached to the upper; anda torsion assembly includinga torsion member coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end;an adjustable medial linkage having a first end connected to the medial end of the torsion member and a distal end connected to the shoe; andan adjustable lateral linkage having a first end connected to the lateral end of the torsion member and a distal end connected to the shoe,wherein movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in an initial rotational direction, the torsion member providing a resisting force in an opposite rotational direction to restore the medial linkage and the lateral linkage toward the equilibrium position and provide stability for the shoe.

2. The shoe of claim 1, wherein the medial linkage includes a medial arm and a medial post, the medial arm including the first end of the medial linkage and the medial post including the distal end of the medial linkage, the medial post having a proximal end rotatably connected to a second end of the medial arm, and wherein the lateral linkage includes a lateral arm and a lateral post, the lateral arm including the first end of the lateral linkage and the lateral post including the distal end of the lateral linkage, the lateral post having a proximal end rotatably connected to a second end of the lateral arm.

3. The shoe of claim 1, further comprising at least one anchor for coupling the torsion member to the shoe.

4. The shoe of claim 1, wherein the torsion member, the medial linkage, and the lateral linkage are disposed external to the shoe.

5. The shoe of claim 1, wherein the torsion member is coupled to the upper.

6. The shoe of claim 1, wherein the torsion member is at least partially disposed through the sole structure.

7. The shoe of claim 1, wherein the distal end of the medial linkage and the distal end of the lateral linkage are mounted to the sole structure.

8. The shoe of claim 1, wherein the medial linkage and the lateral linkage are mounted to a brace encircling the upper.

9. The shoe of claim 1, wherein the torsion member is removable from the medial linkage and the lateral linkage.

10. The shoe of claim 1, wherein the medial linkage has a different stiffness than the lateral linkage.

11. The shoe of claim 1, wherein the torsion member comprises a rate-dependent material.

12. The shoe of claim 1, wherein the torsion member has an asymmetric stiffness to bias the equilibrium position toward the medial linkage or the lateral linkage.

13. The shoe of claim 1, further comprising a limiter sheath at least partially surrounding the torsion member for limiting rotation of the torsion member.

14. The shoe of claim 1, further comprising an inertial measurement unit (IMU) for providing adaptive stiffness of the torsion member.

15. A torsion assembly for a shoe, the torsion assembly comprising:a torsion member configured to be coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end;a medial linkage including a medial arm and a medial post, the medial arm having a first end connected to the medial end of the torsion member, the medial post having a proximal end rotatably connected to a second end of the medial arm and a distal end configured to be connected to the shoe; anda lateral linkage including a lateral arm and a lateral post, the lateral arm having a first end connected to the lateral end of the torsion member, the lateral post having a proximal end rotatably connected to a second end of the lateral arm and a distal end configured to be connected to the shoe,wherein movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in an initial rotational direction, the torsion member providing a resisting force in an opposite rotational direction to restore the medial linkage and the lateral linkage toward the equilibrium position and provide stability for the shoe.

16. The torsion assembly of claim 15, wherein the torsion member is removable from the medial linkage and the lateral linkage.

17. The torsion assembly of claim 15, wherein the medial linkage has a different stiffness than the lateral linkage.

18. The torsion assembly of claim 15, wherein the torsion member comprises a rate-dependent material.

19. The torsion assembly of claim 15, wherein the torsion member has an asymmetric stiffness to bias the equilibrium position toward the medial linkage or the lateral linkage.

20. A torsion assembly for a shoe, the torsion assembly comprising:a torsion member configured to be coupled to the shoe in a medial-lateral orientation and having a medial end and a lateral end;a medial linkage including a medial arm and a medial post, the medial arm having a first end connected to the medial end of the torsion member, the medial post having a proximal end rotatably connected to a second end of the medial arm and a distal end configured to be connected to the shoe; anda lateral linkage including a lateral arm and a lateral post, the lateral arm having a first end connected to the lateral end of the torsion member, the lateral post having a proximal end rotatably connected to a second end of the lateral arm and a distal end configured to be connected to the shoe,wherein movement of the medial linkage or the lateral linkage away from an equilibrium position twists the torsion member in a rotational direction, the torsion member providing an augmenting force in the rotational direction to bias the medial linkage and the lateral linkage away from the equilibrium position and provide asymmetric stability of the shoe.

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