JP7288897B2 - Athletic prosthesis sole - Google Patents

Description

TECHNICAL FIELD The present invention relates to a sole to be attached to the contact area of a prosthetic leg for competition, and more particularly to a sole for prosthetic leg for competition that achieves both improved anti-slip performance and securing of contact area.

Conventionally, a prosthetic leg for competition (hereinafter referred to as a prosthetic leg for competition or simply a prosthetic leg) has a leaf spring-shaped foot portion that extends toward the toe side through the curved portion, and the contact area extends in an arc from the toe to the curved portion side. called) is known. Such a prosthetic foot for sports having a leaf spring-like foot portion is generally provided with a sole that contacts the road surface on the bottom surface of the contact area.

For example, Patent Literature 1 exemplifies a sole suitable for sports events such as jogging and running, which is attached to the lower surface of a bent leaf spring-shaped athletic prosthetic leg. That is, Patent Document 1 describes a sole having spikes attached to the lower surface of the sole that contacts the road surface, and a sole provided with a large number of outsole portions each having a hexagonal contact surface.

JP 2016-150189 A

However, in the sole exemplified in Patent Document 1, no consideration is given to preventing the prosthetic leg from slipping, that is, anti-slip properties. For example, when the race is held in the rain or the like, the race will be run on a wet road surface. At that time, if a water film exists on the road surface, the water film is interposed between the bottom surface of the sole and the road surface, and as a result of preventing the bottom surface of the sole from contacting the ground, a slip occurs. In particular, on road surfaces with a low coefficient of friction μ, such as asphalt and cobblestone, the wearer of the prosthetic leg may hesitate to accelerate further. Therefore, in order for the wearer of the prosthetic leg to fully demonstrate his running skills as an athlete, a sole having high anti-slip performance is required.

In addition, as the overall speed of the competition using the prosthetic leg for competition is increasing, securing a contact area with the road surface is becoming an issue in order to enable stable running.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a sole for a prosthetic leg for sports that achieves improved anti-slip performance and secures a ground contact area.

The inventor has diligently studied means for solving the above problems. That is, when the bottom surface of the sole of the prosthetic foot for competition was examined in detail, grooves were provided on the bottom surface to give an edge component by unevenness, and by securing the grip force on the road surface through this edge component, the user could run. I came up with the idea that it is possible to prevent slippage at the time. Furthermore, the present inventors have found that it is possible to ensure a contact area with the road surface by devising the shape of the unevenness, and have completed the present invention.

The sole of the prosthetic foot for sports according to the present invention is a joint that extends in an arc from the toe to the side of the curved portion of the prosthetic foot for sports that has a leaf spring-like foot portion that extends toward the toe side via at least one curved portion. A sole worn on a region, the sole having a bottom surface shaped to follow the extending shape of the contact area, the bottom surface being defined by a plurality of widthwise grooves extending in the widthwise direction of the sole, at least One width direction land portion is provided, and both side walls of the width direction land portion facing the plurality of width direction grooves are stepped from the groove bottom side of the plurality of width direction grooves toward the ground surface side. It is characterized by

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a sole for a prosthetic leg for competition that achieves improved anti-slip performance and secures a ground contact area.

1 is a side view of an athletic prosthesis fitted with a sole according to one embodiment of the present invention; FIG. FIG. 10 is a diagram showing a pattern on the bottom surface of the sole according to one embodiment of the present invention; FIG. 3 is a sectional view taken along line II-II of FIG. 2; It is a figure which shows the variation of a width direction land part. It is a figure which shows the variation of a width direction land part. It is a figure which shows the variation of a width direction land part. FIG. 10 is a diagram for stepwise explanation of the movement of the foot and the contact pattern when the wearer wears the athletic prosthesis and runs straight. FIG. 10 is a diagram for stepwise explanation of the movement of the foot and the contact pattern when the wearer wears the athletic prosthesis and runs straight. FIG. 10 is a diagram for stepwise explanation of the movement of the foot and the contact pattern when the wearer wears the athletic prosthesis and runs straight. FIG. 10 is a diagram for stepwise explanation of the movement of the foot and the contact pattern when the wearer wears the athletic prosthesis and runs straight. FIG. 10 is a diagram showing a bottom pattern of a sole according to another embodiment of the present invention;

Hereinafter, the sole of the prosthetic leg for sports of the present invention (hereinafter also referred to as sole) will be described in detail by exemplifying embodiments thereof with reference to the drawings.

FIG. 1 is a side view of an athletic prosthesis 1 fitted with a sole 5 according to a first embodiment of the present invention. A prosthetic leg 1 for competition has a leaf spring-like foot portion 2, and a sole 5 is attached to a contact area on the tip side thereof. Although not shown, the proximal end of the leg 2 is connected to a socket via an adapter, and the wearer wears the prosthetic leg by accommodating the stump of the wearer's leg in the socket. be able to. Adapters and sockets are used according to the position of the stump of the leg, such as a thigh prosthesis and a lower leg prosthesis. FIG. 1 shows the foot 2 and the sole 5 of the wearer of the athletic prosthesis 1 in an upright position.

Hereinafter, in the present embodiment, in the height direction of the prosthetic leg for competition, the side where the leg 2 is connected to the adapter is called the connection side, and the side that contacts the road surface S is called the ground side. Also, the toe T of the prosthetic leg 1 for competition refers to the foremost point where the leg 2 extends from the connection side and terminates.

In this embodiment, the foot portion 2 of the prosthetic leg 1 for competition has a shape extending in a plate shape toward the toe T side via at least one curved portion, one curved portion 3 in the illustrated example. In FIG. 1, the leg portion 2 includes, in order from the connection side to the ground side, a straight portion 2a, a curved portion 2b that is convex toward the toe T side, a curved portion 3 that is convex to the rear side in the foot longitudinal direction Y, and a concave portion toward the ground side. and a ground contact portion 4 extending toward the toe T side in an arc which is convex toward the ground contact side.

Although the material of the leg portion 2 is not limited, it is preferable to use carbon fiber reinforced plastic or the like from the viewpoint of strength and weight reduction.

The grounding portion 4 has a grounding area 4s extending in an arc from the toe T toward the curved portion 3, and the sole 5 is attached to the grounding area 4s. The contact area 4s refers to the entire area in contact with the road surface S when the wearer wearing the prosthesis for competition 1 runs straight. contact with the road surface S via.

Although the material of the sole 5 is not particularly limited, for example, rubber or the like can be used.

The sole 5 has a shape that follows the extending shape of the contact area 4s. Further, the ground side of the sole 5 is the sole bottom surface 5s. As shown in FIG. 1, the sole bottom surface 5s has a shape in which arcs X1 and X2 extend from the toe T side to the curved portion 3 side. In this embodiment, the arc X1 and the arc X2 have mutually different radii of curvature, but they may have the same radii of curvature.

Hereinafter, the direction in which the sole bottom surface 5s extends from the toe T side to the curved portion 3 side is referred to as the Y direction, and the width direction of the sole bottom surface 5s orthogonal to the Y direction is referred to as the W direction. Furthermore, the thickness direction of the sole 5 is called the Z direction.

FIG. 2 is a diagram showing the pattern of the sole bottom surface 5s according to one embodiment of the present invention. In the illustrated example, at least one widthwise land portion 10 defined by a plurality of widthwise grooves 20 extending in the W direction, and in the illustrated example, three rows of widthwise land portions 10 are arranged on the sole bottom surface 5s.

3A is a cross-sectional view perpendicular to the extending direction of the widthwise land portion 10, that is, a cross-sectional view taken along line II-II in FIG. As shown in the figure, in the width direction land portion 10, both side walls 10Wa and 10Wb facing the plurality of width direction grooves 20 are arranged in two steps from the side of the groove bottoms 20b of the plurality of width direction grooves 20 to the side of the ground surface 10s. shape. In the illustrated example, the side wall 10Wa has a side wall portion Sa1 extending in the Z direction and a side wall portion Ca1 extending in the Y direction forming the first step P1 from the side of the groove bottom 20b. It has a side wall portion Sa2 extending in the Z direction toward 10s. The side wall 10Wb has a side wall portion Sb1 extending in the Z direction and a side wall portion Cb1 extending in the Y direction, which form the first step P1 from the groove bottom 20b side, and further extends from the side wall portion Cb1 toward the ground plane 10s. It has a side wall portion Sb2 extending in the Z direction. In this embodiment, the step formed by the side wall portions Sa2 and Sb2 and the ground plane 10s is referred to as a second step P2.

By making the side walls 10Wa and 10Wb stepwise, the sole bottom surface 5s is provided with a high edge function, and when the wearer of the prosthetic leg 1 for competition performs a straight running motion on the width direction land portion 10, the grip on the road surface S is provided. It is possible to demonstrate the force and improve the anti-slip performance. Furthermore, when the road surface S side, that is, the second step P2 touches the road surface S first and is compressed, the water intervening between the first step P1 and the road surface S is pushed out to the road surface S side. Since the water can be discharged efficiently, the drainage performance is improved, and a higher anti-slip performance can be obtained. Further, by compressing the second step P2, the sidewall portions Ca and Cb1 of the first step P1 can also be brought into contact with the road surface S, so that a contact area can be secured.

The side walls 10Wa and 10Wb may have any number of steps as long as they are stepped, but with a two-step stepped configuration, the drainage performance can be improved while maintaining the high rigidity of the width direction land portion 10. can.

In the present embodiment, the height h1 in the Z direction of the width direction land portion 10 and the maximum length w1 in the direction orthogonal to the extending direction of the width direction land portion 10 are the same as the height h1. is preferably 1.5 times or more and 10.0 times or less. According to this configuration, when the wearer of the prosthetic leg 1 for competition runs, it is possible to impart sufficient rigidity to the width direction land portion 10 while imparting appropriate flexibility to the bottom surface 5s of the sole.

Further, the maximum length w1 perpendicular to the extending direction of the width direction land portion 10 and the length w2 of the ground contact surface 10s of the width direction land portion perpendicular to the extending direction of the width direction land portion 10 are as follows. It is preferable to satisfy the relationship of formula (1).
(Formula (1)) 0.3 ≤ (w1-w2) / w1 ≤ 0.9
By setting the relationship (w1-w2)/w1 between the maximum length w1 of the width direction land portion 10 and the length w2 of the ground contact surface 10s to 0.3 or more, the drainage performance of the stepped side wall is more effective. By setting it to 0.9 or less, it is possible to secure a sufficient ground contact area at the moment when the width direction land portion 10 first touches the ground, and to improve the anti-slip performance.

The maximum length w1 perpendicular to the extending direction of the widthwise land portion 10 is preferably 2.0 mm or more and 8.0 mm or less. By setting the width to 2.0 mm or more, sufficient land portion rigidity is imparted to the width direction land portion 10, and by setting the width to 8.0 mm or less, flexibility of the sole bottom surface 5s in the Y direction can be maintained. Preferably, the length w1 is 3.0 mm or more and 6.5 mm or less, more preferably 3.8 mm or more and 4.5 mm or less.

Further, the length w2 of the ground contact surface 10s of the widthwise land portion perpendicular to the extending direction of the widthwise land portion 10 is preferably 0.5 mm or more and 2.5 mm or less. By setting the width to 0.5 mm or more, it is possible to secure a sufficient ground contact area at the moment when the width direction land portion 10 first touches the ground, and it is possible to improve the anti-slip performance. Furthermore, by setting the width to 2.5 mm or less, the drainage performance of the stepped side wall can be exhibited more effectively.

Further, the maximum height h1 of the widthwise land portion 10 in the Z direction and the maximum height h2 of the step P2 including the ground contact surface 10s of the widthwise land portion 10 must satisfy the following formula (2): is preferred.
(Formula (2)) 0.25≤h2/h1≤0.67
By setting the height of the step P2 including the ground contact surface 10s, which first contacts the road surface S, to be 0.25 times or more the maximum height h1 of the widthwise land portion 10, the drainage performance of the stepped side wall is improved. can be more effectively exerted, and by setting it to 0.67 times or less, when the wearer of the prosthetic leg 1 for competition runs, while giving the sole bottom surface 5s appropriate flexibility, the width direction land portion 10 can be imparted with sufficient rigidity.

In addition, it is preferable that the maximum height h1 in the Z direction of the width direction land portion 10 is 1.0 mm or more and 7.0 mm or less. By making it 1.0 mm or more, it is possible to sufficiently ensure drainage performance, and by making it 7.0 mm or less, when the wearer of the prosthetic leg 1 for competition runs, the flexibility and rigidity of the bottom surface 5s of the sole are maintained. can be compatible. It is more preferably 2.0 mm or more and 3.5 mm or less, and even more preferably 2.4 mm or more and 3.5 mm or less.

Further, the maximum height h2 in the Z direction of the step P2 including the ground contact surface 10s of the widthwise land portion 10 is preferably 0.5 mm or more and 2.5 mm or less. By making it 0.5 mm or more, the drainage performance of the stepped side wall can be more effectively exhibited, and by making it 2.5 mm or less, when the wearer of the prosthetic leg 1 for competition runs, the sole bottom surface 5 s Sufficient rigidity can be imparted to the width direction land portion 10 while imparting appropriate flexibility to the width direction land portion 10 . More preferably, the maximum height h2 is 0.7 mm or more and 1.5 mm or less, and even more preferably 1.2 mm or more and 1.5 mm or less.

Variations in the shape of the widthwise land portion 10 are shown below.
FIG. 3B shows the widthwise land portion 10 in which the side walls 10Wa ₂ and 10Wb ₂ are formed in a three-stepped shape. In the illustrated example, the side wall 10Wa ₂ has a side wall portion Sa1 extending in the Z direction and a side wall portion Ca1 extending in the Y direction, forming the first step P1 from the groove bottom 20b side, and forming the second step P2. It has a side wall portion Sa2 extending in the Z direction from the side wall portion Ca1 toward the ground plane 10s, a side wall portion Ca2 extending in the Y direction, and a side wall extending in the Z direction from the side wall portion Ca2 toward the ground plane 10s. It has a portion Sa3. The side wall _10Wb2 has a side wall portion Sb1 extending in the Z direction and a side wall portion Cb1 extending in the Y direction, forming the first step P1 from the groove bottom 20b side, and forming the second step P2. , a side wall portion Sb2 extending in the Z direction from the side wall portion Cb1 toward the ground plane 10s, a side wall portion Cb2 extending in the Y direction, and a side wall portion Sb3 extending in the Z direction from the side wall portion Cb2 toward the ground plane 10s. have. In the example shown in FIG. 3B, the step formed by the sidewall portions Sa3 and Sb3 and the ground plane 10s is referred to as the third step P2. According to the above configuration, it is possible to increase the edge component in the Y direction and obtain higher drainage performance. Further, when the width direction land portion 10 is grounded, the step P3 and the step P2 are sequentially compressed from the side of the ground contact surface 10s, so that a sufficient contact area can be secured.

FIG. 3C shows a widthwise land portion 10 having side walls 10Wa ₃ and 10Wb ₃ . The step of the width direction land portion 10 closest to the groove bottom 20b has a shape in which the length perpendicular to the extending direction of the width direction land portion 10 gradually increases from the side of the ground contact surface 10s toward the side of the groove bottom 20b. there is That is, as shown in the illustrated example, the step P1 of the width direction land portion 10 closest to the groove bottom is the width of the groove bottom 20b side from the length w3 perpendicular to the extending direction of the width direction land portion 10 on the side of the ground contact surface 10s. The length orthogonal to the extending direction of the width direction land portion 10 gradually increases until reaching the maximum length w1 orthogonal to the extending direction of the direction land portion 10 . When the width direction land portion 10 touches the ground, the step P2 is compressed from the side of the ground contact surface 10s. Rigidity is increased, and a ground contact area can be secured efficiently.

In the illustrated example, the distance w4 in the Y direction from the boundary e1 between the widthwise land portion 10 and the groove bottom 20b on the side of the toe T to the side wall portion Ca1 of the step P1 and the widthwise land portion on the curved portion 3 side The Y-direction distance w5 from the boundary e2 between 10 and the groove bottom 20b to the side wall portion Cb1 of the step P1 has the same length, but may have a different length. For example, if the Y-direction distance w4 is made longer than the Y-direction distance w5, the slope of the step P1 to the groove bottom 20b becomes gentler on the toe T side than on the curved portion 3 side. As a result, uneven wear of the widthwise land portion 10 can be suppressed when the portion of the sole bottom surface 5s in contact with the road surface S shifts from the curved portion 3 side to the toe T side.

Although the Y-direction distance w4 and the Y-direction distance w5 differ depending on the wearer of the prosthetic leg 1 for competition, the type of competition, etc., they are preferably 0.5 mm or more and 2.5 mm or less, respectively. By setting it to 0.5 mm or more, it is possible to secure the rigidity of the width direction land portion 10 while improving the drainage performance, and by setting it to 2.5 mm or less, it is possible to secure the contact area with the road surface S and drain water. performance can be fully exhibited. It is preferably 0.5 mm or more and 1.5 mm or less, more preferably 0.5 mm or more and 1.0 mm or less.

3D, a side wall portion Sa2 extending in the Z direction from the side wall portion Ca1 of the side wall 10Wa ₄ toward the ground surface 10s has an arc r1 having a center of curvature radius outside the width direction land portion 10, and the side wall A side wall portion Sb2 extending in the Z direction from the side wall portion Cb1 of _10Wb4 toward the ground contact surface 10s has an arc r2 having a center of curvature radius outside the width direction land portion 10 . By configuring the side wall portions Sa2 and Sb2 to include arcs, the rigidity of the width direction land portion 10 can be increased.

Next, with reference to FIGS. 4A, 4B, 4C, 4D and 2, the preferred arrangement and number of widthwise land portions 10 will be described.

FIGS. 4A, 4B, 4C, and 4D are diagrams for stepwise explanation of the movement of the foot portion 2 and the contact pattern with the bottom surface 5s of the sole when the wearer wearing the athletic prosthesis 1 runs straight. is. The upper part of each drawing is a side view of the foot part 2 and the sole 5, and the lower part of each drawing is a contact form of the bottom surface 5s of the sole when the wearer wearing the artificial leg 1 for competition runs straight. It shows transition.

FIG. 4A shows a state in which the wearer lowers the sports prosthesis 1 lifted up onto the road surface S, and the whole weight is applied to the sports prosthesis 1. FIG. As shown in the lower part of the drawing, when the prosthesis 1 is first put down on the road surface S, the contact area of the sole bottom surface 5s is near the center of the bottom surface, and Y Directionally spaced regions.

FIG. 4B shows a state in which the wearer steps forward from the state of FIG. 4A while the entire weight is applied to the athletic prosthesis 1. FIG. In the case of running by an able-bodied person, it is common to step on the ground in order from the heel side of the shoe sole that touches the ground first toward the toe side, but the prosthetic leg 1 for competition is curved more than the point where it first touches the ground. The contact area has moved to the part 3 side.

FIG. 4C shows a state in which the wearer swings forward with the leg opposite to the side on which the prosthesis for competition 1 is worn, and starts a kicking motion of the prosthesis for competition 1 . When this kicking motion is started, the prosthetic leg for competition 1 touches the ground in a region on the toe T side of the region shown in FIGS. 4A and 4B on the bottom surface 5s of the sole.

FIG. 4D shows the state just before leaving the road surface S in the final stage when the wearer kicks the prosthetic leg 1 for competition. In order to kick from the toe T of the bottom surface 5s of the sole, the area on the side of the toe T is further grounded than in FIG. 4C.

In this embodiment, as shown in FIG. 2, the widthwise land portion 10 is arranged in a region corresponding to the ground contact region shown in FIG. 4A. That is, it is a state in which the wearer lowers the prosthetic leg 1 lifted up to the road surface S, and the entire weight is applied to the prosthetic leg 1 for competition. Here, it is important that the area grips the road surface S sufficiently so that the wearer can maintain the balance of the whole body even if the wearer puts the whole weight on the prosthetic leg 1 for competition. By arranging the width direction land portion 10 in such an area, a high edge function is imparted by the stepped side wall, a sufficient grip force on the road surface S is secured, and a high anti-slip performance is imparted to the area, thereby increasing the ground contact area. can be ensured.

In FIG. 2 described above, by arranging the width direction land portions 10 in three rows in the ground contact area shown in FIG. 4A, the anti-slip performance of the bottom surface 5s of the sole can be enhanced and the ground contact area can be reliably secured.

Next, with reference to FIGS. 4A, 4B, 4C, 4D and 5 above, the groove pattern of the bottom surface 5s of the sole of the prosthetic foot for competition according to another embodiment will be described. The sole of the prosthetic leg for competition according to the second embodiment has a basic configuration similar to that of the first embodiment, and is formed with a width direction land portion having a chamfered portion, but is different from the first embodiment. , the shape of the land portion in the width direction is different.

The pattern of the sole bottom surface 5s of the sole for athletic prosthesis according to the second embodiment is based on the above-described knowledge regarding the transition of the ground contact form of the sole bottom surface 5s.

In FIG. 5 , the sole bottom surface 5 s has widthwise land portions 100 , 110 , 120 and 140 defined by widthwise grooves 200 and extending in the widthwise direction W, and a sipe 130 .

The widthwise land portion 100 includes a widthwise extending portion 100a extending in a substantially zigzag shape in the W direction, a toe-side protruding portion 100b extending toward the toe T side from a bent portion that is bent in a convex direction toward the toe T side, and a curved portion. It has a shape including a bending portion-side protruding portion 10c extending toward the bending portion 3 from a bending portion that is bent in a convex direction toward the portion 3 side. The widthwise land portion 110 has a shape including a widthwise extending portion 110a, a tiptoe side projecting portion 110b, and a curved portion side projecting portion 110c. The width direction land portion 140 has the same shape as the width direction land portion 110 .

Here, the area where the width direction land portions 100 and 110 are arranged is the ground contact area shown in FIGS. This is the area where the stepping motion is performed in the state where the Therefore, it is important that this area grips the road surface S sufficiently so that the wearer can maintain the balance of the whole body even if the wearer puts the whole weight on the prosthetic leg 1 for competition. By forming the width-direction extending portion 100a in a zigzag shape and further forming the toe-side projecting portion 100b and the curved-portion-side projecting portion 100c, the drainage function is effectively exerted along the Y direction, It is possible to secure a sufficient grip force with the prosthetic leg to prevent the prosthetic leg from slipping, that is, to improve the anti-slip performance.

The width of the widthwise land portion 110 is larger than that of the widthwise land portion 100 . As shown in FIG. 4B , in the state where the wearer stepped on the ground immediately after landing, the ground contact area changes to the curved portion 3 side of the first ground contact area, that is, to the side opposite to the forward direction of the wearer. Here, the movement of the wearer's upper body trying to move forward and the direction of transition of the ground contact area are temporarily reversed, and the kicking motion in the second half of the ground contact form shown in FIGS. 4C to 4D. This is the stage at which a high driving force is required to move toward By arranging the width direction land portion 110 having a width larger than that of the width direction land portion 100 closer to the curved portion 3 than the width direction land portion 100 and increasing the land portion ratio, the rigidity of this arrangement region is increased, and the stepping action is performed. It achieves a high propulsive force to smoothly connect the kicking action.

The widthwise land portion 120 extends in a substantially zigzag shape in the W direction, and is composed of a widthwise extending portion 120a, which is a repetition of widening and narrowing of the width of the land portion, and a bent portion that is bent in a convex direction toward the toe T side. , the toe-side protruding portion 120b extending in the direction in which the widthwise extending portion 120a extends, and the bending portion on the bending portion 3 side in the convex direction, the widthwise extending portion 120a extending from the toe side protruding portion 120b. It is a shape including a bending portion side projecting portion 120c that extends in a convex direction.

The area in which the width direction land portion 120 is arranged is the area that touches the ground when the kicking motion of the prosthetic leg 1 for competition is started, as shown in FIG. 4C. By adopting a shape in which the width of the land portion changes, it is possible to improve the drainage performance while increasing the rigidity of the land portion. In other words, it is possible to increase the width of the land while avoiding slipperiness due to the increased width of the land by forming a shape in which a portion having a relatively large width and a portion having a relatively small width coexist. can.

In addition, the sole bottom surface 5s of the present embodiment includes a plurality of sipes 130 extending linearly in a direction inclined with respect to the W direction in a region from the edge of the toe T side toward the curved portion 3 side. is preferred. The area where the sipe 130 is arranged is for the wearer to swing forward the leg opposite to the side on which the prosthetic leg for competition 1 is worn and perform a kicking motion of the prosthetic leg for competition 1, as shown in FIG. 4D. is the area of This region is a region where wear is particularly likely to progress because the wearer contacts the ground in order toward the toe T, and the wearer presses and slides the road surface S with the bottom surface 5s of the sole. Therefore, in this area, it is important to improve the wear resistance performance and maintain the resistance to slipping when the tire touches the ground.

In particular, a certain area from the edge of the sole bottom surface 5s on the side of the toe T where the sipe 130 is formed is an area corresponding to the arc X1 continuing from the toe T with a certain radius of curvature in FIG. As shown in 4D, the wearer wearing the athletic prosthesis 1 tended to touch the ground last when performing a kicking action, resulting in more severe wear. Therefore, it is necessary to provide particularly high wear resistance performance in this region. Therefore, the sipe 130 having a width smaller than that of the grooves formed in other regions is formed to distribute the edge component without impairing the rigidity. Therefore, the sole bottom surface 5s can be protected from severe abrasion, and the service life of the foot portion 2 itself can be extended.

In any of the embodiments, in the pattern of the sole bottom surface 5s, fluorine is preferably applied to groove walls and groove bottoms forming widthwise grooves that define widthwise land portions. By applying fluorine to the groove walls and the groove bottom of the width direction groove, the drainage performance of the sole bottom surface 5s can be enhanced.

1: Prosthetic leg for competition 2: Foot 2a: Straight portion 2b, 2c: Curved portion 3: Curved portion 4: Contact portion 4s: Contact area 5: Sole 5s: Bottom of sole 10: Width Directional land portion 10Wa, 10Wb, _10Wa2 , 10Wb2, _{10Wa3 , 10Wb3} , _10Wa4 , 10Wb4: side wall 20: width direction groove _20b : groove bottom e1, e2: boundary P1, P2, P3 : step Sa1, Sa2, Sa3, Ca1, Ca2, Sb1, Sb2, Sb3, Cb1, Cb2: side wall portion 100, 110, 120, 140: width direction land portion 130: sipe 100a, 110a, 120a: width Direction extending portions 100b, 110b, 120b: toe-side protrusions 100c, 110c, 120c: curved portion-side protrusions Y: direction in which the sole bottom surface 5s extends from the toe T side to the curved portion 3 side W: Width direction of sole bottom surface 5s orthogonal to Y direction, Z: thickness direction of sole 5

Claims (4)

A sole to be attached to a contact area extending in an arc from the toe to the curved portion side of a prosthetic leg for athletics having a leaf spring-shaped foot portion extending toward the toe side via at least one curved portion,
The sole has a bottom surface shaped to follow the extended shape of the contact area,
the bottom surface has at least one widthwise land section defined by a plurality of widthwise grooves extending in the widthwise direction of the sole;
In the width direction land portion, both side walls facing the plurality of width direction grooves are stepped from the groove bottom side of the plurality of width direction grooves toward the ground surface side,
The step of each of the side walls of the width direction land portion closest to the groove bottom has a shape in which the length perpendicular to the extending direction of the width direction land portion gradually increases from the ground contact surface side toward the groove bottom side. has
Of the side walls of the width direction land portion, the step closest to the groove bottom of the side wall on the toe side has a maximum length orthogonal to the extending direction of the width direction land portion, A sole for a prosthetic leg for competition, characterized in that the step closest to the groove bottom side of the side wall on the side of the curved portion of the wall is longer than the maximum length perpendicular to the extending direction of the widthwise land portion. 2. The sole of a prosthetic leg according to claim 1, wherein said side walls facing said plurality of width direction grooves are stepped in two steps from said plurality of width direction grooves toward the ground surface side. The maximum length w1 perpendicular to the extending direction of the width direction land portion and the length w2 of the ground contact surface of the width direction land portion perpendicular to the extending direction of the width direction land portion are expressed by the following equation: 3. The sole of the prosthetic leg for competition according to claim 1 or 2, which satisfies the relationship (1).
(Formula (1)) 0.3 ≤ (w1-w2) / w1 ≤ 0.9 The maximum height h1 of the width direction land portion in the thickness direction of the sole and the maximum height h2 of the step including the ground contact surface of the width direction land portion satisfy the following formula (2): A sole for a prosthetic leg for sports according to any one of claims 1 to 3.
(Formula (2)) 0.25≤h2/h1≤0.67

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