Patent Publication Number: US-2021161683-A1

Title: Sole of athletic prosthetic leg

Description:
TECHNICAL FIELD 
     The present disclosure relates to a sole attached to a ground contact region of an athletic prosthetic leg, in particular, to a sole of an athletic prosthetic leg which inhibits slip of the prosthetic leg during a competition. 
     BACKGROUND 
     Conventionally, a prosthetic leg for a competition (hereinafter, referred to as an athletic prosthetic leg or simply referred to as a prosthetic leg) having a leaf-spring-like leg portion which extends via a curved portion to a side of a toe and in which a ground contact region extends from the toe to a side of the curved portion in an arc has been well-known. To such an athletic prosthetic leg having the leaf-spring-like leg portion, generally, a sole which abuts a road surface is attached to a bottom surface of the ground contact region. 
     For example, Patent Literature 1 illustrates a sole which is attached to a lower surface of a curved leaf-spring-like athletic prosthetic leg to correspond to sporting events such as jogging or running. In other words, Patent Literature 1 discloses a sole to which a spike is attached at a lower surface of the sole contacting a road surface or a sole provided with a number of outsole portions each having a hexagonal contact patch. 
     CITATION LIST 
     Patent Literature 
     PTL 1: Japanese Patent Laid-Open No. 2016-150189 
     SUMMARY 
     Technical Problem 
     However, in the sole illustrated in Patent Literature 1, inhibiting slip of the prosthetic leg, that is, anti-slip property is not at all considered. For example, running on a wet road surface is required in a case of a competition in rainfall etc. At that time, when a water film exists on the road surface, the water film is interposed between a bottom surface of the sole and the road surface while hindering ground contact of the bottom surface, resulting that slip is caused. Especially, on a road with a low coefficient friction μ such as asphalt and a stone pavement, there has been a case where a wearer of the prosthetic leg hesitates further acceleration. Accordingly, a sole having a high anti-slip property has been required for the wearer of the prosthetic leg to satisfactorily exert his running skill as athletes. 
     An object of the present disclosure is to provide a sole of an athletic prosthetic leg having a high anti-slip property. 
     Solution to Problem 
     The inventor earnestly studied means to solve the problem. In other words, while a ground contact form of an athletic prosthetic leg has been reviewed in detail, the inventor newly found that the athletic prosthetic leg illustrates a unique ground contact form caused by the shape of a leaf-spring-like leg portion. Further, the inventor found that a high anti-slip property can be achieved by allowing a bottom surface of a sole to correspond to a ground contact form which is unique to the athletic prosthetic leg to separate functions of the sole, and completed the present disclosure. 
     According to the present disclosure, there is provided a sole of an athletic prosthetic leg, the athletic prosthetic leg having a leaf-spring-like leg portion extending to a side of a toe via at least one curved portion, the sole being configured to be attached to a ground contact region of the athletic prosthetic leg, the ground contact region extending from the toe to a side of the curved portion in an arc, wherein the sole includes a bottom surface having a shape conforming to an extending shape of the ground contact region, and, in the bottom surface, a region at the side of the curved portion has a higher drainage performance compared with a region other than the region at the side of the curved portion, the region at the side of the curved portion being defined by a border as a line extending in a width direction of the leg portion through a contact point with a road surface in a standing state of a wearer who wears the athletic prosthetic leg. 
     Advantageous Effect 
     Due to the present disclosure, a sole of an athletic prosthetic leg having a high anti-slip property can be provided. Attachment of this sole to the athletic prosthetic leg provides an effect of fully exerting an athlete&#39;s skill. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the accompanying drawings: 
         FIG. 1  is a side view of an athletic prosthetic leg to which a sole according to a first embodiment of the present disclosure is attached; 
         FIG. 2A  is a drawing for explaining in stages movement of a leg portion and a ground contact form in a case where the athletic prosthetic leg is worn and a wearer executes straight running; 
         FIG. 2B  is a drawing for explaining in stages the movement of the leg portion and the ground contact form in a case where the athletic prosthetic leg is worn and the wearer executes straight running; 
         FIG. 2C  is a drawing for explaining in stages the movement of the leg portion and the ground contact form in a case where the athletic prosthetic leg is worn and the wearer executes straight running; 
         FIG. 2D  is a drawing for explaining in stages the movement of the leg portion and the ground contact form in a case where the athletic prosthetic leg is worn and the wearer executes straight running; 
         FIG. 3  is a drawing for explaining each region of a bottom surface; 
         FIG. 4  is a drawing which illustrates a pattern of the bottom surface of the sole of the athletic prosthetic leg according to the first embodiment; 
         FIG. 5  is a drawing which illustrates a pattern of the bottom surface of the sole of the athletic prosthetic leg according to a second embodiment; 
         FIG. 6  is a drawing which illustrates a pattern of the bottom surface of the sole of the athletic prosthetic leg according to a third embodiment; 
         FIG. 7  is a drawing which schematically illustrates a pattern element constituting a pattern by recesses and protrusions; 
         FIG. 8  is a drawing which schematically illustrates a pattern element constituting a pattern by recesses and protrusions; 
         FIG. 9A  is a drawing which illustrates the bottom surface of the sole to which a pattern by recesses and protrusions is applied; 
         FIG. 9B  is a drawing which illustrates the bottom surface of the sole to which a pattern by recesses and protrusions is applied; 
         FIG. 10A  is a schematic cross-sectional view along a width direction of the leg portion of the sole; 
         FIG. 10B  is a schematic cross-sectional view along the width direction of the leg portion of the sole; 
         FIG. 10C  is a schematic cross-sectional view along the width direction of the leg portion of the sole; 
         FIG. 11A  is a perspective view which illustrates a ground contact portion and the sole; 
         FIG. 11B  is a perspective view which illustrates the ground contact portion and the sole; 
         FIG. 12A  is a perspective view which illustrates the sole and a tab for sticking before the sole is mounted to the ground contact portion; 
         FIG. 12B  is a drawing for explaining the thicknesses at a border between a toe-side tab for sticking and the sole and at a portion adjacent to the border; and 
         FIG. 12C  is a drawing for explaining the thicknesses at a border between a curved-portion-side tab for sticking and the sole and at a portion adjacent to the border. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, with reference to the drawings, a sole of an athletic prosthetic leg of the present disclosure (hereinafter, it is also referred to as a sole) will be explained in detail with illustration of embodiments thereof. 
       FIG. 1  is a side view of an athletic prosthetic leg  1  to which a sole  5  according to a first embodiment of the present disclosure is attached. The athletic prosthetic leg  1  has a leaf-spring-like leg portion  2 , and the sole  5  is attached to a ground contact region at its tip side. Additionally, while illustration is omitted, a base end portion of the leg portion  2  is connected to a socket via an adapter and the socket houses a stump of a wearer&#39;s leg, whereby the wearer can wear the prosthetic leg. The adapter and the socket which correspond to the position of the stump of the leg, such as an above-knee prosthesis and a below-knee prosthesis, are used.  FIG. 1  illustrates the leg portion  2  and the sole  5  in a standing state of the wearer who wears the athletic prosthetic leg  1 . 
     Hereinafter, in this embodiment, in a height direction of the athletic prosthetic leg, a side where the leg portion  2  is connected to the adapter is referred to as a connection side, and a side where the leg portion  2  contacts a road surface S is referred to as a ground contact side. Also, a toe T of the athletic prosthetic leg  1  refers to a point at the forefront as a termination of the leg portion  2  extending from the connection side. Further, a direction extending from the toe T in parallel with the road surface S is referred to as a leg portion front-rear direction Y. Further, a widthwise direction of the leg portion  2  is referred to as a width direction W. 
     In this embodiment, the leg portion  2  of the athletic prosthetic leg  1  has a plate-like extending shape to the side of the toe T via at least one curved portion, in the illustrated example, one curved portion  3 . In  FIG. 1 , the leg portion  2  is constituted by, in the order from the connecting side to the ground contact side, a straight portion  2   a , a curved portion  2   b  which is convex to the side of the toe T, the curved portion  3  which is convex to a rear side in the leg portion front-rear direction Y, a curved portion  2   c  which is concave to the ground contact side and a ground contact portion  4  which is convex to the ground contact side to extend to the side of the toe Tin an arc. 
     Additionally, although the material of the leg portion  2  is not limited, from a viewpoint of strength and weight saving, fiber reinforced plastic etc. is preferably used. 
     The ground contact portion  4  includes a ground contact region  4   s  extending from the toe T to the side of the curved portion  3  in an arc at the ground contact side, and the sole  5  is attached to the ground contact region  4   s . The ground contact region  4   s  refers to the entire region abutting the road surface S when the wearer who wears the athletic prosthetic leg  1  executes straight running movement, and in a state that sole  5  is attached, the ground contact region  4   s  abuts the road surface S via the sole  5 . 
     The sole  5  has a shape conforming to an extending shape of the ground contact region  4   s . Also, the ground contact side of the sole  5  is a bottom surface  5   s . As illustrated in  FIG. 1 , the bottom surface  5   s  has a shape in which an arc X 1  and an arc X 2  are continued from the toe T side to the curved portion  3  side. While the arc X 1  and the arc X 2  have a different radius of curvature to each other in this embodiment, they may include the same radius of curvature. 
     Also, the bottom surface  5   s  has different properties at one side and the other side, which are defined by a border as a line extending in the width direction W through a point C as a contact point with the road surface S in a standing state of the wearer when the athletic prosthetic leg  1  is worn. The point C is a point which firstly contacts the road surface S in arriving at standing. In other words, the standing state refers to a state that the wearer firstly contacts the road surface S by lowering the athletic prosthetic leg  1  to the road surface S from a state that the wearer supports his body by a healthy leg wearing no prosthetic leg when a prosthetic leg is used for only one leg, or the wearer supports his body by one prosthetic leg when prosthetic legs are used for both legs. Additionally, the point C is determined depending on the shape or an attachment aspect etc. of the prosthetic leg. In other words, the inventor newly conceived that the border for separating functions of the bottom surface  5   s  from a finding related to a ground contact form obtained from an experiment which will be described later uses the point C which is the contact point with the road surface S in the wearer&#39;s standing state as a standard. 
     An experiment result of the ground contact form of the bottom surface  5   s  as described above will be explained below using  FIGS. 2A, 2B, 2C and 2D .  FIGS. 2A, 2B, 2C and 2D  are drawings for explaining in stages movement of the leg portion  2  and the ground contact form of the bottom surface  5   s  when the wearer who wears the athletic prosthetic leg  1  having the above configuration executes straight running. In each drawing, an upper portion is a side view of the leg portion  2  and the sole  5 , and a lower portion illustrates a transition of the ground contact form of the bottom surface  5   s  when the wearer who wears the athletic prosthetic leg  1  executes straight running. 
     In other words,  FIG. 2A  illustrates a state that the wearer lowers the raised athletic prosthetic leg  1  to the road surface S and the entire weight is loaded on the athletic prosthetic leg  1 . As illustrated in the lower portion of the drawing, in the bottom surface  5   s , a region at the side of the curved portion  3  from the point C contacts the ground. 
       FIG. 2B  illustrates a state that the wearer steps forward, from the state of  FIG. 2A , while the entire weight remains to be loaded on the athletic prosthetic leg  1 . In a case of running of a healthy person, such a step form is generally applied that ground contact is sequentially executed from a heel side toward a toe side of a shoe sole which firstly contacts to the ground, while in the athletic prosthetic leg  1 , the ground contact region is moved to the side of the curved portion  3  from a portion which firstly contacts the ground. 
       FIG. 2C  illustrates a state that the wearer starts a kick-out movement of the athletic prosthetic leg  1  by shaking an opposite leg from the leg wearing the athletic prosthetic leg  1  forward. Entering into this kick-out movement, the athletic prosthetic leg  1  contacts the ground at a region at the side of the toe T from the point C of the bottom surface  5   s.    
       FIG. 2D  illustrates a state that the wearer is in a final stage of kicking out the athletic prosthetic leg  1  just before separating from the road surface S. To kick out from the toe T of the bottom surface  5   s , ground contact is executed further at the side of the toe T than in  FIG. 2C . 
     Based on the experimental result illustrated in  FIGS. 2A, 2B, 2C and 2D , as illustrated in  FIG. 3 , firstly, the bottom surface  5   s  is divided into a curved portion side region Q 1  and a toe side region Q 2  with a border of the point C. Additionally,  FIG. 3  is a drawing for explaining each region of the bottom surface  5   s , and the sole bottom surface  5   s  is illustrated in a plane. 
     In other words, the curved portion side region Q 1  is a region at the side of the curved portion  3  defined by a border as a line BL extending in the width direction W of the leg portion  2  through the point C in the bottom surface  5   s . As illustrated in  FIGS. 2A and 2B , the curved portion side region Q 1  is a region where the wearer firstly contacts the ground and executes a step movement in a state that the entire weight is loaded to the athletic prosthetic leg  1 . Consequently, it is vital that the curved portion side region Q 1  fully grips the road surface S such that the entire body is balanced even when the entire weight of the wearer is loaded on the athletic prosthetic leg  1 . Thus, to prevent slip due to a water film interposed between the bottom surface  5   s  and the road surface S, drainage performance of the curved portion side region Q 1  needs to be higher than a portion other than the curved portion side region Q 1 , that is, the toe side region Q 2 . 
     In other words, since the curved portion side region Q 1  has a higher drainage performance compared with the portion other than the curved portion side region Q 1 , the sole  5  of the athletic prosthetic leg  1  prevents slip due to the water film and achieves a high anti-slip property. 
     On the other hand, the toe side region Q 2  is a region at the side of the toe T defined by the border as the line BL extending in the width direction W of the leg portion  2  through the point C in the bottom surface  5   s . The toe side region Q 2  is a region where the wearer shakes an opposite leg from a leg wearing the athletic prosthetic leg  1  forward to execute the kick-out movement of the athletic prosthetic leg  1 . The toe side region Q 2  sequentially contacts the ground toward the toe T, and the wearer presses the road surface S by the bottom surface  5   s  to slidingly contact the ground, so that the toe side region Q 2  is a region which easily develops abrasion in particular. Thus, wear resistance performance of the toe side region Q 2  needs to be higher than that of the curved portion side region Q 1 . 
     In other words, with the toe side region Q 2  having a higher wear resistance performance than the curved portion side region Q 1 , early abrasion of the toe side region Q 2  is avoided, and as a result, the entire surface of the sole  5  of the athletic prosthetic leg  1  is gently worn and a long service life of the sole  5  can be achieved. 
     Also, it is preferable that each of the curved portion side region Q 1  and the toe side region Q 2  is further divided as illustrated in  FIG. 3  based on the ground contact form illustrated in  FIGS. 2A to 2D  such that each portion has property corresponding to the ground contact form. 
     In other words, of the toe side region Q 2  illustrated in  FIG. 3 , a portion Q 2 - 1  corresponds to the arc X 1  which continues from the toe T with a constant radius of curvature in  FIG. 1 . The portion Q 2 - 1  finally contacts the ground when the wearer who wears the athletic prosthetic leg  1  executes the kick-out movement, so that severer abrasion has been inclined to occur. Thus, the portion Q 2 - 1  needs to have an especially high wear resistance performance. In other words, in the toe side region Q 2 , the portion Q 2 - 1  has a higher wear resistance performance than a remaining portion Q 2 - 2 , so that the sole  5  is protected from severe abrasion and the long service life of the leg portion  2  itself can be achieved. 
     Next, in the curved portion side region Q 1 , a portion Q 1 - 1  at the side of the toe T from a center M 1  of a maximum length L 1  along the leg portion front-rear direction Y is a region which firstly contacts the ground, so that prevention of slip is especially necessary such that the wearer achieves a balance of his body. Thus, the portion Q 1 - 1  preferably has a further higher drainage performance than a remaining portion Q 1 - 2  in the curved portion side region Q 1  such that slip is more surely prevented and a further stable running is achieved. 
     Also, the portion Q 1 - 2  is a portion at the side of curved portion  3  from the center M 1  of the maximum length L 1 . As illustrated in  FIG. 2B , in the curved portion side region Q 1 , the ground contact portion is changed to the side of the curved portion  3  from the portion Q 1 - 1  which firstly contacts the ground, that is, the portion Q 1 - 2  at the opposite side from a direction that the wearer advances. At the time of ground contact of the portion Q 1 - 2 , movement of an upper body in which the wearer tries to move forward and movement of the ground contact portion are temporarily opposite, so that a high propulsive force is needed for the kick-out movement at the latter half of the ground contact form. Consequently, firstly, it is vital that the portion Q 1 - 2  has a higher rigidity than the portion Q 1 - 1 . Since the portion Q 1 - 2  has a higher rigidity than the portion Q 1 - 1 , the step movement is smoothly continued to the kick-out movement, and a high propulsive force can be achieved. 
     Especially, in a case where the bottom surface  5   s  includes a pattern constituted by a plurality of recesses and protrusions, the portion Q 1 - 2  preferably has a larger edge component in the width direction W of the leg portion  2  than the portion Q 1 - 1 . Also, a negative ratio of the portion Q 1 - 2  is preferably smaller than that of the portion Q 1 - 1 . Here, the negative ratio refers to a percentage in an area of a recessed portion to the road surface S in a planar view in a total area of the bottom surface  5   s  in a planar view. With this configuration, a high propulsive force can be exerted in running. 
     Also, to exert the propulsive force effectively, the portion Q 1 - 2  preferably has a larger edge component in the width direction W of the leg portion  2  than the toe side region Q 2 . Further, a negative ratio of the portion Q 1 - 2  is preferably larger than that of the toe side region Q 2 . With this configuration, the portion Q 1 - 2  can exert a high propulsive force when the wearer executes the kick-out movement. 
     Concrete means to achieve the above-described properties to be applied to each portion of the bottom surface  5   s  includes, for example, designing a pattern constituted by recesses and protrusions by grooves and the like formed on the bottom surface  5   s , designing the surface property of the bottom surface  5   s , designing the cross-sectional shape of the sole  5  and designing the material of the sole  5 . 
     Hereinafter, firstly, the first embodiment and a second embodiment will be explained about a case where each function is applied by design of the pattern constituted by recesses and protrusions of the bottom surface  5   s .  FIG. 4  is a drawing which illustrates a pattern of the bottom surface  5   s  of the sole  5  in the athletic prosthetic leg  1  according to this embodiment. 
     In the pattern illustrated in  FIG. 4 , a plurality of land portions  10  and a plurality of land portions  11  which are defined by a plurality of grooves extending in the width direction W are arranged in the curved portion side region Q 1 . The land portions  10  are arranged to the side of the toe T from the land portions  11 . The land portions  10  are shaped to include a width direction extending portion  10   a  extending in the width direction W to be substantially zigzag-shaped, a toe side protruding portion  10   b  extending to the side of the toe T from a bent portion bending to be convex to the side of the toe T and a curved portion side protruding portion  10   c  extending to the side of the curved portion from a bent portion bending to be convex to the side of the curved portion  3 . The land portions  11  are shaped to include a width direction extending portion  11   a , a toe side protruding portion  11   b  and a curved portion side protruding portion  11   c . The width direction extending portions  10   a  and  11   a  are zig-zag shaped, thereby fully ensuring the edge component. Further, by forming the toe side protruding portions  10   b  and  11   b  as well as the curved portion side protruding portions  10   c  and  11   c , the edge component is further increased, and the water film interposed between the bottom surface  5   s  and the road surface S can be efficiently cut on both sides in the leg portion front-rear direction Y, thereby achieving a high drainage performance. 
     Also, in  FIG. 4 , a plurality of land portions  12  which are defined by a plurality of grooves extending in the width direction W are arranged in the toe side region Q 2 . The land portions  12  are shaped to include a width direction extending portion  12   a  extending in the width direction W to be substantially zig-zag shaped, a toe T side protruding portion  12   b  extending to be convex in a direction that the width direction extending portion  12   a  extends from a bent portion bending to be convex to the side of the toe T and a curved portion side protruding portion  12   c  extending to be convex in a direction that the width direction extending portion  12   a  extends from a bent portion bending to be convex to the side of the curved portion  3 . Further, a plurality of linear grooves  13  intermittently extending along the zig-zag shape extending in the width direction W are formed in the toe side region Q 2 . The land portions  12  are arranged to the side of the curved portion  3  from the linear grooves  13  and the linear grooves  13  are formed to the side of the toe T from the land portions  12 . Additionally, as illustrated in the drawing, a land portion  14  having the same shape as the land portions  11  may be formed in the toe side region Q 2 . 
     In  FIG. 4 , a land portion width w 2  of the width direction extending portion  10   a  of the land portions  10  is larger than a land portion width w 3  of the width direction extending portion  11   a  of the land portions  11 . Also, a land portion width w 4  of the width direction extending portion  12   a  of the land portions  12  is larger than the land portion widths w 2  and w 3 . 
     In this configuration, in the curved portion side region Q 1 , a percentage in an area of a groove portion which is concave to the road surface S in a planar view in a total area of the bottom surface  5   s  in a planar view, that is, a negative ratio is larger than that in the toe side region Q 2 . Thus, in the curved portion side region Q 1 , more water can be taken in a recessed groove and can be discharged. Thus, the curved portion side region Q 1  has a higher drainage performance than the toe side region Q 2 . 
     On the other hand, the toe side region Q 2  has a higher wear resistance performance than the curved portion side region Q 1 . The reason is that the toe side region Q 2  has a smaller negative ratio than the curved portion side region Q 1  to maintain a high rigidity. 
     Additionally, in the toe side region Q 2 , the linear groove  13  is formed in the portion Q 2 - 1 . With this configuration, the ground contact portion Q 2 - 1  has a larger rigidity than the remaining portion Q 2 - 2  in the toe side region Q 2  to include a further higher wear resistance performance. 
     Also, in  FIG. 4 , in the curved portion side region Q 1 , the negative ratio of the portion Q 1 - 1  is larger than that of the portion Q 1 - 2 , so that more water can be taken in the grooves and can be discharged. In other words, the portion Q 1 - 1  has a further higher drainage performance than the portion Q 1 - 2 . 
     Further, in the curved portion side region Q 1 , the land portions  11  are arranged in the portion Q 1 - 2 . Moreover, as described before, the land portion width w 3  of the land portions  11  is larger than the land portion width w 2  of the land portions  10 . Thus, the portion Q 1 - 2  has a larger land portion rigidity than the portion Q 1 - 1 . Further, the portion Q 1 - 2  has a larger edge component in the width direction W than the portion Q 1 - 1 . Also, as described before, the negative ratio of the portion Q 1 - 2  is smaller than that of the portion Q 1 - 1 . 
     Also, the portion Q 1 - 2  has a larger edge component in the width direction W than the toe side region Q 2  and further, has a larger negative ratio. 
     Next, a sole of an athletic prosthetic leg according to the second embodiment of the present disclosure will be explained with reference to  FIG. 5 . In the sole of the athletic prosthetic leg according to the second embodiment, properties included by each portion of the sole are the same as in the first embodiment. 
     In a bottom surface  50   s  of the sole  5  illustrated in  FIG. 5 , a plurality of land portions  100 ,  110 ,  120  and  140  which are defined by a plurality of grooves extending in the width direction W are arranged. The land portions  100 ,  110 ,  120  and  140  correspond to the land portions  10 ,  11 ,  12  and  14  illustrated in  FIG. 4 . While the same shape as that of the corresponding land portion is illustrated in a planar view of the bottom surface  50   s , in a depth direction of the grooves defining each land portion, the land portions  100 ,  110 ,  120  and  140  have a two-stage structure. The two-stage structure will be explained with reference to the land portions  120 . The land portions  120  have a step-like structure in which a second-stage block  120 B is located above a first-stage block  120 A at the side of the groove bottom in a thickness direction of the sole  5 . A stepped portion of the first-stage block  120 A is illustrated by a thick line in the drawing. While the second-stage block  120 B has a smaller surface area than the first-stage block  120 A in a planar view, the second-stage block  120 B and the first-stage block  120 A has the same shape. In a case where the wearer who wears the athletic prosthetic leg  1  executes straight running movement, when the second-stage block  120 B firstly contacts the ground to be crushed, water interposed between the first-stage block  120 A and the road surface S is pushed out to the side of the road surface S, thereby discharging the water effectively. Further, the first-stage block  120 A contacts the ground after the second-stage block  120 B, which fully ensures a foot print area with the road surface S while drainage performance is not deteriorated. The land portions  100 ,  110  and  140  also include stepped portions illustrated by a thick line and have the step-like structure. 
     Next, a sole of an athletic prosthetic leg according to a third embodiment of the present disclosure will be explained with reference to  FIG. 6 . In a bottom surface  500   s  of the sole  5  of the athletic prosthetic leg according to the third embodiment, a plurality of land portions  15  each having the shape of a square with rounded corners in a planar view are defined by forming a recessed groove in the portion Q 1 - 1  of the curved portion side region Q 1 . Also, land portions  16   a  and  16   b  are arranged at the side of the curved portion  3  from the land portions  15  in the curved portion side region Q 1 . The land portions  16   a  and  16   b  are applied the shape of a square with rounded corners in a planar view by forming a recessed groove in the bottom surface  500   s , and have a larger area in the planar view than the land portions  15 . Also, the land portion  16   b  has a larger area in a planar view than the land portion  16   a . Further, land portions  17   a  and  17   b  having the same shape as the land portions  16   a  and  16   b  are defined also in the toe side region Q 2 . Further, a land portion  18   a  having the shape of a rectangle with rounded corners in a planar view is formed in the toe side region Q 2  at the side of the toe T from the land portions  17   a  and  17   b , and a semi-land portion  18   b  is defined at the side of the toe T from the land portion  18   a  in an aspect that a depth of the groove is tapered toward the side of the toe T. Moreover, a plurality of linear grooves  19   a  and a plurality of linear grooves  19   b  which are inclined to the width direction W are continuously arranged along the width direction W at the side of the toe T from the semi-land portion  18   b . The linear grooves  19   a  and the linear grooves  19   b  are inclined in an opposite direction from each other to the width direction W. 
     With this configuration, the curved portion side region Q 1  and the toe side region Q 2  illustrated in  FIG. 6  can apply the same function as the curved portion side region Q 1  and the toe side region Q 2  in the sole of the athletic prosthetic leg according to the first embodiment and the second embodiment. 
     Additionally, in the case where each function is applied by the pattern constituted by recesses and protrusions of the bottom surface of the sole  5 , the pattern is not limited to ones in the embodiments, and patterns illustrated below can be used. Each pattern will be explained with reference to  FIGS. 7, 8 and 9 . Additionally,  FIGS. 7 and 8  schematically illustrate pattern elements constituting a pattern by recesses and protrusions. By varying the number of the pattern elements or the specification thereof for every region or portion described above, a function required for each region and each portion can be applied. 
     For example, as illustrated in  FIG. 7 , a pattern in which a plurality of vertical grooves  30  extending along the leg portion front-rear direction Y are formed can be used. With this configuration, water taken in the vertical grooves  30  flows accompanied with movement of the sole, so that the water can be efficiently discharged from an end portion of the vertical grooves  30 . By varying the width or the depth of the vertical grooves  30  for each portion of the bottom surface of the sole  5 , a pattern which prioritizes any of drainage performance and wear resistance performance can be applied. 
     Also, as illustrated in  FIG. 8 , a pattern in which a plurality of grooves  31  and  32  continuing annularly are formed can be used. Due to the annular grooves  31  and  32 , intake and discharge of water can be efficiently executed irrespective of a direction of various inputs of force acting on the bottom surface of the sole  5 . By varying the width, depth or diameter of a ring of the annular grooves  31  and  32  for each portion of the bottom surface  5   s , a pattern which prioritizes any of drainage performance and wear resistance can be applied. 
     Additionally, the bottom surface of the sole  5  may have a pattern in which only the vertical grooves or the only the annular grooves are formed, or a pattern with a combination of the vertical grooves and the annular grooves. Further, a pattern with a combination of the annular grooves and lateral grooves may be applied. 
     Further, as a pattern of the bottom surface of the sole  5 , a pattern illustrated in  FIG. 9A or 9B  can be used. In this pattern, in a bottom surface  5000   s  of the sole  5 , a plurality of vertical grooves  33  which are open at one end or both ends are formed at sole end edges at the side of the toe T as well as the side of the curved portion  3 , and a plurality of inclined grooves  34 ,  35 ,  36  and  37  which communicate with the vertical grooves  33 , inclinedly extend in the width direction W and are open at the sole end edges are formed. As illustrated in the drawing, in the curved portion side region Q 1 , the inclined grooves  34 ,  35  extend inclinedly to the side of the curved portion  3  from the center in the width direction W of the bottom surface  5000   s  toward the sole end edges. On the other hand, in the toe side region Q 2 , the inclined grooves  36 ,  37  extend inclinedly to the side of the toe T from the center in the width direction W of the bottom surface  5000   s  toward the sole end edges. With this configuration, drainage performance in accordance with the ground contact form of the athletic prosthetic leg  1  can be achieved. In other words, in the bottom surface  5000   s , a ground contact portion is changed to the portion Q 1 - 2  at the side of the curved portion  3  from the portion Q 1 - 1  which firstly contacts the ground. In accordance with a transition movement, water taken in the grooves flows along the inclination of the grooves from the side of toe T to the side of the curved portion  3 , and is discharged from an opening at an end edge of the bottom surface  5000   s . Further, accompanied with a transition movement of the ground contact portion from the curved portion side region Q 1  to the toe side region Q 2 , the water taken in the grooves flows along the inclination of the grooves from the side of the curved portion  3  to the side of the toe T, and is discharged from an opening at an end edge of the sole  5 . With this operation, efficient drainage can be achieved. While the groove width of each groove is constant in  FIG. 9A , in  FIG. 9B , the groove width is enlarged in a region in which drainage performance is prioritized, while the groove width is reduced in a region in which wear resistance performance is prioritized. 
     Additionally, in any of the examples explained so far, the depth of the groove and the number of grooves formed at the bottom surface of the sole  5  is arbitrary. By enlarging the depth of the groove, the drainage performance can be more improved. Further, the drainage performance can be also improved by increasing the number of grooves. 
     Also, in addition to improvement of the drainage performance of the entire bottom surface of the sole  5  due to the patterns explained so far, the wear resistance performance and the drainage performance can be controlled for each region and each portion by designing the surface property of the bottom surface of the sole  5 , for example, varying the introduction density of a sipe, the surface roughness and a riblet and the like illustrated below. 
     For example, the drainage performance can be improved by forming a plurality of sipes which is narrower than grooves on the bottom surface of the sole  5 . The more the number of the sipes increases, the higher the drainage performance can be obtained. As for the wear resistance performance, this relation may be reversed. The same comment is applied to the surface roughness and the riblet below. 
     The surface roughness is adjusted by applying micro recesses and protrusions to the bottom surface of the sole  5 , thereby improving the drainage performance and the wear resistance performance. When a coarser surface roughness is used, water can be taken in the micro recesses and protrusions, so that a high drainage performance can be achieved. 
     Also, by providing so-called riblets in which fine grooves are continuously aligned in the width direction W or the leg portion front-rear direction Y, water interposed between the road surface S and the sole  5  sequentially infiltrates each narrow groove of the riblet due to capillary action, so that a higher drainage performance can be achieved. 
     Further, by providing water repellent finishing to a surface of the bottom surface of the sole  5 , water applied to a surface of the bottom surface of the sole  5  can be efficiently eliminated, so that the drainage performance can be improved. 
     Next, a case where each function is applied by designing the cross-sectional shape of the sole  5  will be explained.  FIGS. 10A, 10B and 10C  are schematic cross-sectional views along the width direction W of the sole  5 . 
     In  FIGS. 10A and 10B , the thickness of the sole  5  is largest at the center in the width direction W, and it is tapered toward the side of the sole end edge in the width direction W. The sole  5  may have the shape in which the thickness is linearly tapered as illustrated in  FIG. 10A , while it may have the shape in which the thickness is tapered in an arc as illustrated in  FIG. 10B . With this configuration, at the time of ground contact of the bottom surface  5   s , water on the road surface S is pushed out from the center side in the width direction W of the sole  5  to the side of the sole end edge, so that efficient drainage can be executed. Additionally, the entire sole  5  may have this configuration, or only a part of the sole  5  may have this configuration. 
     Also, as illustrated in  FIG. 10C , the sole  5  may have a structure that it has a plurality of cones which are convex to the ground contact side. In the illustrated example, the sole  5  has a plurality of quadrangular pyramids  40  which are convex to the ground contact side. With this configuration, due to the plurality of quadrangular pyramids  40 , the bottom surface of the sole  5  is spike-like, which achieves ground contact from an apex by efficiently cutting a water film existing between the bottom surface of the sole  5  and the road surface S. Consequently, a high drainage performance can be achieved. Moreover, since the water can pass through a gap formed between the plurality of quadrangular pyramids  40 , a high drainage performance can be achieved. Additionally, not limited to a quadrangular pyramid, a cone or polygonal cones other than a quadrangular pyramid may be applied. Moreover, wear resistance performance can also be achieved by varying the size of a pyramid in accordance with each region of the bottom surface of the sole  5 . 
       FIGS. 11A and 11B  are perspective views illustrating the ground contact portion  4  and the sole  5 . As illustrated in  FIG. 11A , the sole  5  has a hidden groove  41  which is open to the side of the ground contact portion  4  at the side of a border surface between the ground contact portion  4  and the sole  5 . The hidden groove  41  extends along the width direction W to be open at both end edges of the sole  5 . With this configuration, water on the road surface is taken in the hidden groove  41  from both ends of the leg portion  2  in the width direction W and discharged. This prevents the water from infiltrating a portion between the bottom surface of the sole  5  and the road surface S, so that a high drainage performance can be obtained. Additionally, although not illustrated in  FIG. 11A , in a case where an adhesive is interposed between the ground contact portion  4  and the sole  5 , the sole  5  is formed with a groove or a recess portion which is open to the side of the adhesive at the side of a border surface with the adhesive. 
     Also, as illustrated in  FIG. 11B , the sole  5  may have the configuration that includes a combined groove in which a circular groove  42  formed on the bottom surface of the sole  5  communicates with a groove  43  penetrating through the sole  5  along the width direction W. With this configuration, water interposed between the bottom surface of the sole  5  and the road surface S can be taken in from the circular groove  42  and can be discharged efficiently from an end portion of the groove  43  penetrating in the width direction W. Also, by combining such combined groove with a groove constituted by recesses and protrusions at the bottom surface of the sole  5 , rigidity of the sole  5  can be adjusted and property in accordance with each region of the bottom surface of the sole  5  can be applied. 
     Subsequently, a case where each function is applied by designing a part or the entire of the material of the sole  5  will be explained. For example, felt, a sponge or non-woven fabric is used to a part or the entire of the sole  5  and drainage performance can be improved due to a water absorption operation of each material. Also, the same effect can be obtained by using foamed rubber to a part or the entire of the sole  5  due to a water abrasion operation of the foamed rubber. 
     Additionally, the sole  5  of the athletic prosthetic leg  1  according to the present disclosure explained so far can be manufactured, for example, by a method of processing a rubber sheet by a laser light, a method of using a mold and a manufacturing method using a 3D printer. 
     Also, in the athletic prosthetic leg  1  according to the present disclosure, the sole  5  is attached to the ground contact region  4   s  via an adhesive. However, attachment means is not limited to the adhesive, and attachment may be executed using fasteners such as a belt. Further, in the present disclosure, while the sole  5  is attached to the ground contact region  4   s  by directly abutting, a cushion member (not shown) or a binding material may be interposed between the sole  5  and the ground contact region  4   s.    
     Here, an example of attachment means of the sole  5  will be explained below with reference to  FIGS. 12A, 12B and 12C .  FIG. 12A  is a perspective view which illustrates the sole  5  and a tab for sticking before the sole  5  is attached to the ground contact portion  4 . Additionally, in  FIG. 12A , a pattern of the bottom surface  5   s  is omitted. As illustrated, a toe-side tab for sticking  6  and a curved-portion-side tab for sticking  7  are integrally connected to the sole  5 . The toe-side tab for sticking  6  is fan-shaped and connected along an end edge at the side of the toe T of the sole  5 , and moreover, is divided by two cuts  8   a ,  8   b . Moreover, the curved-portion-side tab for sticking  7  is connected to an end edge at the side of the curved portion  3  of the sole  5 .  FIG. 12B  is a drawing for explaining thicknesses at a border between the toe-side tab for sticking  6  and the sole  5  and at a portion adjacent to the border. In addition,  FIG. 12C  is a drawing for explaining the thicknesses at a border between the curved-portion-side tab for sticking  7  and the sole  5  and at a portion adjacent to the border. As illustrated in  FIG. 12B , the toe-side tab for sticking  6  extends with a constant thickness th 2  which is thinner than a thickness th 1  of the sole  5 , and the thickness gradually increases toward a border B 1  with the sole  5 . Also, the curved-portion-side tab for sticking  7  extends with a thickness th 3  which is thinner than the thickness th 1  of the sole  5 , and the thickness gradually increases toward a border B 2  with the sole  5 . With this configuration, when the sole is attached to the ground contact portion  4 , close attachment can be executed without any deflection or gap between the sole  5  and the ground contact portion  4 . For example, assuming that the thickness th 1  of the sole  5  is 2.25 to 3.0 mm, the thickness th 2  of the toe-side tab for sticking  6  and the thickness th 3  of the curved-portion-side tab for sticking  7  may be 1.5 to 2.0 mm. 
     Examples 
     While Examples of the present disclosure will be explained hereinafter, the present disclosure is not limited to this. 
     Prototypes are produced for each of soles of Examples and soles of comparative examples, and performance evaluation is executed. The soles of Examples are applied a function such as drainage performance specified in the present disclosure due to variation of an arrangement of the pattern or the grooves of the bottom surface of the sole. Of the soles of comparative examples, in a comparative example 1, a pattern of the sole is uniform at the bottom surface. Also, in a comparable example 2, a pattern is different from that of the present disclosure. 
     As for drainage performance and wear resistance performance, assuming that an index of Q 1 - 1  of the comparative example 1 is 100, it is presented that the drainage performance and the wear resistance performance of the corresponding portion are excellent as the indexes increase. 
     The sole of comparative examples and the sole of Examples produced experimentally as described above are attached to the athletic prosthetic leg illustrated in  FIG. 1  to evaluate anti-slip property and wear resistance performance. 
     In the comparative example 1 and Example 4, drainage performance and wear resistance performance of each portion of each of the regions Q 1 , Q 2  are evaluated from a result of calculation by simulation. Also, in the comparative example 2 and Examples 1 to 3, the drainage performance and the wear resistance performance of each portion of each of the regions Q 1 , Q 2  are evaluated by the same method as in the comparative example 1 and Example 4. 
     [Anti-Slip Property] 
     In a state that a water film of 1 mm is filled on a glass surface and a load of 980N is applied to an athletic prosthetic leg, the following test is executed. A spring scale is attached to a connection portion of the athletic prosthetic leg and a stump of a leg, and the athletic prosthetic leg is pulled to the side of the toe in the leg portion front-rear direction by the spring scale. At the time when the athletic prosthetic leg starts to slip, indexation of a value of the spring scale is executed. 
     Additionally, assuming that an index of the comparative example 1 is 100, it is presented that anti-slip property is excellent as the index increases. 
     [Wear Resistance Performance] 
     A player with a healthy left leg wears an athletic prosthetic leg at a right side, and executes 200 km running on a public road, and thereafter, indexation of an appearance of the entire bottom surface is executed. Additionally, assuming that an index of the comparative example 1 is 100, it is presented that the sole has an excellent wear resistance performance as the index increases. In the comparative example 1 and Example 4, a player with a healthy left leg wore the athletic prosthetic leg at a right side, and executed 200 km running on a public road, and thereafter, indexation of an appearance of the entire bottom surface was executed. Also, in the comparative example 2 and Examples 1 to 3, indexation of the appearance of the entire bottom surface is executed by the same method as in the comparative example 1 and Example 4. 
     
       
         
           
               
               
               
               
               
               
               
             
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Comparative 
                 Comparative 
                   
                   
                   
                   
               
               
                   
                 example 1 
                 example 2 
                 Example 1 
                 Example 2 
                 Example 3 
                 Example 4 
               
               
                   
                   
               
             
            
               
                   
               
            
           
           
               
               
               
               
               
               
               
               
               
            
               
                 Drainage 
                 Curved 
                 Portion Q1-1 
                 100 
                 100 
                 110 
                 110 
                 110 
                 120 
               
               
                 performance 
                 portion side 
                 Portion Q1-2 
                 100 
                 100 
                 110 
                 110 
                 110 
                 110 
               
               
                   
                 region Q1 
               
               
                   
                 Toe side 
                 Portion Q2-1 
                 100 
                 110 
                 80 
                 90 
                 90 
                 90 
               
               
                   
                 region Q2 
                 Portion Q2-2 
                 100 
                 110 
                 50 
                 90 
                 90 
                 90 
               
               
                 Wear 
                 Curved 
                 Portion Q1-1 
                 100 
                 100 
                 80 
                 80 
                 100 
                 100 
               
               
                 resistance 
                 portion side 
                 Portion Q1-2 
                 100 
                 100 
                 100 
                 100 
                 100 
                 100 
               
               
                 performance 
                 region Q1 
               
               
                   
                 Toe side 
                 Portion Q2-1 
                 100 
                 90 
                 100 
                 150 
                 200 
                 200 
               
               
                   
                 region Q2 
                 Portion Q2-2 
                 100 
                 90 
                 100 
                 150 
                 150 
                 150 
               
            
           
           
               
               
               
               
               
               
               
            
               
                 Anti-slip performance 
                 100 
                 103 
                 110 
                 110 
                 110 
                 120 
               
               
                 Wear resistance performance 
                 100 
                 90 
                 100 
                 150 
                 160 
                 160 
               
               
                   
               
            
           
         
       
     
     REFERENCE SIGNS LIST 
     
         
         
           
               1  athletic prosthetic leg 
               2  leg portion 
               2   a  straight portion 
               2   b ,  2   c  curved portion 
               3  curved portion 
               4  ground contact portion 
               4   s  ground contact region 
               5  sole 
               5   s ,  50   s ,  500   s ,  5000   s  bottom surface 
               6  toe-side tab for sticking 
               7  curved-portion-side tab for sticking 
               8   a ,  8   b  cut 
               10 ,  11 ,  12 ,  14  land portion 
               10   a ,  11   a ,  12   a  width direction extending portion 
               10   b ,  11   b ,  12   b  toe side protruding portion 
               10   c ,  11   c ,  12   c  curved portion side protruding portion 
               13 ,  130  linear groove 
               100 ,  110 ,  120 ,  140  land portion 
               15 ,  16   a ,  16   b ,  17   a ,  17   b ,  18   a  land portion 
               18   b  semi-land portion 
               19   a ,  19   b  linear groove 
             X 1 , X 2  arc 
             Q 1  curved portion side region 
             Q 2  toe side region 
             Q 1 - 1 , Q 1 - 2 , Q 2 - 1 , Q 2 - 2  portion 
               30  vertical groove 
               31 ,  32  groove 
               33  vertical groove 
               34 ,  35 ,  36 ,  37  inclined groove 
               40  quadrangular pyramid 
               41  hidden groove 
               42 ,  43  groove