CN210581223U

CN210581223U - Sole and shoe

Info

Publication number: CN210581223U
Application number: CN201790001373.8U
Authority: CN
Inventors: 寺崎志织; 别所亚友; 森安健太
Original assignee: Asics Corp
Current assignee: Asics Corp
Priority date: 2017-10-13
Filing date: 2017-10-13
Publication date: 2020-05-22
Anticipated expiration: 2027-10-13
Also published as: US20210169172A1; WO2019073609A1; EP3524080A4; JPWO2019073609A1; EP3524080A1

Abstract

The utility model provides a sole and shoes. When a midfoot section (14) of a floor panel (10) is divided into an inner midfoot region (20) and an outer midfoot region (22) on both sides in a foot width direction by a predetermined floor center line(s), the floor panel has a rigidity reducing section (32) provided in the inner midfoot region (20), and the rigidity reducing section (32) of the inner midfoot region (20) reduces the bending rigidity of the inner midfoot region (20) based on another element different from the shape of the inner edge (10c) and the outer edge (10d) of the floor panel (10) in a plan view so that the bending rigidity of the inner midfoot region (20) around an axis in the foot width direction is smaller than the bending rigidity of the outer midfoot region (22) around the axis in the foot width direction.

Description

Sole and shoe

Technical Field

The present invention relates to a sole for a shoe.

Background

Conventionally, various attempts have been made to provide shoes with various functions by variously drilling a bottom plate of a sole (see, for example, patent document 1).

[ Prior art documents ]

[ patent document ]

[ patent document 1 ]: international publication No. 2017/046959

However, when a flat support operation or the like is performed during core training, a shoe wearer (hereinafter, simply referred to as a wearer) may take a toe-standing posture. The "toe standing posture" in the present specification means the following posture: in a state where a front foot portion of the floor panel, which will be described later, is grounded, at least a rear foot portion of the floor panel is floated from the ground. The angle of the floor with respect to the ground at a portion of the floor other than the ground contact portion is not particularly limited.

When the muscle strength of the leg of the wearer is weak, it tends to be difficult to stably maintain the toe-standing posture. From the viewpoint of supporting the wearer's movement, it is desirable to provide a shoe sole that achieves good stability in a toe-standing posture. Based on such a viewpoint, the present inventors have made studies and have obtained the following knowledge: the sole described in patent document 1 has room for improvement, and details thereof will be discussed later.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object thereof is to provide a shoe sole that can improve stability in a toe standing posture.

One aspect of the present invention relates to a shoe sole including a bottom plate having a stiffness reducing portion provided in a medial midfoot region when a midfoot region of the bottom plate is divided into a medial midfoot region and a lateral midfoot region on both sides in a foot width direction by a predetermined bottom plate center line, the stiffness reducing portion of the medial midfoot region reducing a bending stiffness of the medial midfoot region based on another element different from a shape of a medial edge and a lateral edge of the bottom plate in a plan view so that the bending stiffness of the medial midfoot region around a foot width direction axis is smaller than the bending stiffness of the lateral midfoot region around a foot width direction axis.

According to the present invention, a shoe sole with improved stability in a toe-standing posture can be provided.

Drawings

Fig. 1 is a plan view of a base plate as an embodiment of the invention.

Fig. 2 is a plan view showing the human foot skeleton.

Fig. 3 is a view of the skeleton of the right foot of the wearer as viewed from the front in the foot length direction, fig. 3(a) shows the positional relationship between the toe and heel of the wearer when they contact the ground, and fig. 3(b) shows the state in which the angle of intersection is increased from the positional relationship of fig. 3 (a).

Fig. 4 is a view showing the calcaneal-cuboid joint surface and the talonary joint surface of the right foot of the wearer, fig. 4(a) shows a positional relationship when the toe and heel of the wearer contact the ground, and fig. 4(b) shows a state in which the intersection angle is increased from the positional relationship of fig. 4 (a).

Fig. 5 is a view for explaining the movement axis of the transverse tarsal joint, fig. 5(a) is a plan view of the skeleton of the right foot, and fig. 5(b) is a view of the skeleton as viewed from the medial side in the foot width direction.

Fig. 6 is a bottom view showing another embodiment of the present invention of the bottom plate provided with the rigidity reducing portion.

Fig. 7 is a bottom view of a base plate as one example of another invention.

Fig. 8 is a perspective view schematically showing a model for simulating a base plate used for analysis.

Fig. 9 is a graph showing the results of the analysis.

Fig. 10 is a diagram for explaining an assumed external torsional resistance region.

Fig. 11 is a diagram showing a base plate of a reference example for analysis.

Fig. 12 is a graph showing the torsional frequency obtained by the analysis.

Fig. 13(a) shows the measurement results of the torsion angle obtained by the experiment, and fig. 13(b) shows the measurement results of the ankle sway amount.

Fig. 14 is a bottom view of the bottom plate of the first modification.

Fig. 15 is a side view of a shoe using the sole according to the first embodiment, as viewed from the medial side in the foot width direction.

Fig. 16 is a bottom view of the bottom plate of the first embodiment.

Fig. 17 is a bottom view of the base plate of the second embodiment.

Fig. 18(a) is a side view of the bottom plate of the second embodiment as viewed from the inner side in the foot width direction, and fig. 18(b) is a side view of the bottom plate as viewed from the outer side in the foot width direction.

Fig. 19(a) is a bottom view of the bottom plate of the second modification, fig. 19(b) is a bottom view of the bottom plate of the third modification, and fig. 19(c) is a bottom view of the bottom plate of the fourth modification.

Fig. 20 is a side view of the shoe sole of the third embodiment as viewed from the same point of view as fig. 15.

Fig. 21 is a side view of the sole of the fourth embodiment as viewed from the same point of view as fig. 15.

[ description of reference numerals ]

10: a base plate; 10 c: an inner rim; 10 d: an outer edge; 10 e: a ground plane; 14: a midfoot portion; 16: a hind foot section; 16 a: toe-side ends; 16 b: a heel side end; 16 c: a continuous surface; 20: a medial midfoot region; 22: a lateral midfoot region; 24: an outer torsional resistance desired region; 26: a first region; 28: a second region; 30: a third region; 32: a rigidity reducing portion; 34: an inner lateral groove portion; 36: a longitudinal groove part; 44: an outer lateral groove portion; 50: a sole; 52: a shoe; 56: a midsole; 58: an outsole.

Detailed Description

Terms used in the present specification will be described. Fig. 1 is a plan view showing a base plate 10 as an example of the present invention. The "foot length direction Lx" in the present specification means a direction along a straight line connecting the toe-most distal end 10a and the heel-most distal end 10b of the base plate 10. The toe side and heel side of the foot length direction Lx are also referred to as the front side and the rear side, respectively. The "foot width direction Y" is a horizontal direction perpendicular to the foot length direction Lx, and the first toe side of the foot of the wearer supported by the bottom plate 10 is the inner side, and the fifth toe side is the outer side. The "total length La" in the foot length direction Lx means the longest length in the foot length direction Lx, and the "total width Lb" in the foot width direction Ly means the longest length in the foot width direction Ly.

Fig. 2 is a plan view showing the human foot skeleton. The foot of the human body mainly comprises cuneiform bones Ba, cuboid bones Bb, navicular bones Bc, talus bones Bd, calcaneus Be, metatarsus Bf and phalanges Bg. The joints of the foot include the MP joint Ja, the metatarsophalangeal joint Jb, and the transtarsal joint Jc. Included in the transverse tarsal joint Jc are: the calcaneus cuboid joint Jc1 formed by the cuboid bones Bb and the calcaneus Be; and a talonavicular joint Jc2 formed by the navicular bone Bc and the talus bone Bd. The "midfoot portion" of the wearer (hereinafter, simply referred to as "midfoot portion in the human body") in the present specification means a portion from the MP joint Ja to the tarsal joint Jc.

Returning to fig. 1. A straight line along the foot width direction Y, which is estimated to pass through the heel-side end of the MP joint Ja of the wearer, is defined as a line p. A straight line along the foot width direction Y, which is estimated to pass through the distal end on the toe side of the transverse tarsal joint Jc of the wearer, is defined as a line q. The lines p and q are, for example, lines obtained by dividing the entire length La of the sole plate 10 in the foot length direction Lx from the toe side toward the heel side into 1.5: 1.0: 1.1, along the foot width direction Y. In the present specification, the "front foot portion 12" of the bottom plate 10 refers to an area on the toe side from the line p, the "middle foot portion 14" of the bottom plate 10 (hereinafter, simply referred to as the "bottom plate middle foot portion 14") refers to an area from the line p to the line q, and the "rear foot portion 16" of the bottom plate 10 refers to an area on the heel side from the line q. The sole midfoot section 14 can also be said to be a region which is estimated to overlap a range from the heel-side end of the wearer's MP joint Ja to the toe-side end of the tarsal joint Jc, that is, a region which is estimated to overlap the human body midfoot section.

The following describes a background of the sole of the present embodiment. As described above, when the muscle strength of the leg of the wearer is weak, it tends to be difficult to stably maintain the toe-standing posture. In addition, when the muscle strength of the leg of the wearer is weak, it is known that the propulsive force is reduced in the kicking-out operation in the latter stage of the leg erection in the walking cycle as a factor of the fall. The wearer is, for example, a female, an elderly person, etc.

From the viewpoint of solving these problems, the present inventors have obtained the following findings: from the standpoint of the foot anatomy of the human body, it is effective to induce a bone locking mechanism in the foot of the human body of the wearer.

Fig. 3 and 4 are views of the bones of the right foot of the wearer as viewed from the front in the foot length direction Lx. Fig. 3 is an external view of a bone, and fig. 4 is a view showing a calcaneal-cuboid joint surface Sja and a talonary joint surface Sjb of a right foot. Fig. 3(a) and 4(a) show the positional relationship of the bones when the toe and heel of the wearer are grounded, and fig. 3(b) and 4(b) show a state in which the intersection angle θ c described later is increased from the positional relationship of fig. 3(a) and 4 (a). An intersection angle between the joint axis Aj1 of the calcaneal-cuboid joint Jc1 of the transverse tarsal joint Jc and the joint axis Aj2 of the talonavicular joint Jc2 as viewed from the front of the foot length direction Lx is defined as θ c.

Fig. 5 is a diagram for explaining the movement axis of the transverse tarsal joint Jc. Fig. 5(a) is a plan view of the bones of the right foot, and fig. 5(b) is a view of the bones as viewed from the foot width direction inward. The transverse tarsal joint Jc has a longitudinal axis and an oblique axis as two motional axes, wherein the longitudinal axis is a joint axis Aj1 of the calcaneal cuboid joint Jc1, and the oblique axis is a joint axis Aj2 of the talonavicular joint Jc 2. Although there are individual differences in bones, the calcaneal cuboid joint Jc1 is generally an axis in which the toe side is inclined inward in the foot width direction by 9 degrees with respect to the horizontal plane and the toe side is inclined upward by 15 degrees with respect to the sagittal plane with reference to the state in which the toe and heel are grounded. The talonavicular joint Jc2 is generally an axis in which the toe side is inclined inward in the foot width direction by 57 degrees with respect to the horizontal plane and the toe side is inclined upward by 52 degrees with respect to the sagittal plane, with reference to the state in which the toe and heel are in contact with the ground.

As shown in fig. 3(b), the bony locking mechanism is achieved by making the angle of intersection θ c somewhat larger than when the wearer's toe and heel are grounded. By increasing the intersection angle θ c, the mobility of the transverse tarsal joint Jc is reduced as compared with the case where the intersection angle θ c is small, and the transverse tarsal joint Jc can be stiffened. This can suppress the fluctuation between the bones constituting the transverse tarsal joint Jc when the foot tip is in the standing posture, and can improve the stability of the standing posture. Further, the rigidity of the transverse tarsal joint Jc makes it possible to smoothly transmit the propulsive force between the bones constituting the transverse tarsal joint Jc, and to improve the propulsive force during the kicking-out operation.

It is known that the intersection angle θ c of the plurality of joint axes constituting the foregoing transverse tarsal joint Jc increases as the external torsion amount at the foot in the human body increases. Thus, in inducing a bone locking mechanism, it is necessary to increase the amount of external torsion at the foot in the human body. Here, the term "outward twisting" means that the heel is twisted in an outward rotating direction with respect to the toe with reference to the positional relationship between the toe and the heel of the human body when they are in contact with the ground. Here, the present inventors obtained the following findings: in order to increase the amount of external torsion in the foot portion of the human body, the following conditions are preferably satisfied.

When the foot of the human body is twisted outward, the base plate 10 is twisted outward following the deformation of the foot of the human body in a range including the foot 14 of the base plate. Thus, in increasing the amount of external torsion at the foot in the human body, it is desirable to reduce the external torsional resistance of the base plate 10 within the range including the foot 14 in the base plate.

In satisfying such a requirement, the present inventors obtained the following findings: as shown in fig. 1, it is effective to provide a rigidity reducing portion 32 that reduces bending rigidity about an axis in a foot width direction (hereinafter, also simply referred to as "bending rigidity") in the medial midfoot region 20 of the midfoot portion 14. The inner midfoot region 20 is a region located inward of two regions on both sides of the midfoot portion 14 in the foot width direction when the midfoot portion is divided into the two regions by a predetermined midfoot center line s. The area of the two areas that is located on the lateral side is referred to as the lateral midfoot area 22.

The base plate center line s is set as a line passing through the center portion of the base plate 10 in the foot width direction Y. In this example, the entire width Lb of the bottom plate 10 is divided into 1.2 pieces from the foot width direction inward to the outward: a straight line along the foot length direction X of 1.0 is set as a floor center line s. The floor center line s in this example is also a portion estimated to be located at the center of the foot width direction of the foot of the wearer. The central portion in the foot width direction is assumed to Be a portion located on a straight line passing through the third metatarsal Bf3 and the calcaneus inner-side raised projection Be1 of the human body. The range in which the medial calcaneus eminence Be1 is supposed to Be located is shown in FIG. 1.

The rigidity reducing portion 32 of the medial midfoot region 20 reduces the bending rigidity of the medial midfoot region 20 so that the bending rigidity of the medial midfoot region 20 is less than the bending rigidity of the lateral midfoot region 22. The phrase "the bending rigidity of the medial midfoot region 20 is smaller than the bending rigidity of the lateral midfoot region 22" herein includes the following two cases. The first case refers to the case where: only medial midfoot region 20 of lateral midfoot region 22 and medial midfoot region 20 is made less rigid in bending. The second case refers to the following case: when the bending rigidity of both the lateral midfoot region 22 and the medial midfoot region 20 is reduced, the reduction in bending rigidity in the medial midfoot region 20 is greater than the reduction in bending rigidity in the lateral midfoot region 22.

The rigidity reducing portion 32 of the medial midfoot region 20 reduces the bending rigidity of the medial midfoot region 20 based on another element different from the shape of the medial edge 10c and the lateral edge 10d of the bottom plate 10 in a plan view. The "other element" refers to, for example, any one or a combination of two of a recess opened in the ground contact surface of the chassis 10 and the elongation property of the material constituting the chassis 10, as described below.

The "recess opened in the ground plane of the chassis 10" means a portion recessed upward from the ground plane of the chassis 10 contacting the road surface. The recess may be a groove portion continuous in the in-plane direction of the ground surface 10e of the chassis 10, or may not be continuous in the in-plane direction. Fig. 6 is a bottom view showing another embodiment of the bottom plate 10 provided with the rigidity reducing portion 32. When the recesses constituting the rigidity reducing portion 32 are not continuous in the in-plane direction, they may be intermittently provided so as to be aligned on an imaginary line such as a straight line or a curved line. This recess is shown in fig. 1 as an inner lateral groove portion 34 extending in the foot width direction Y from the inner edge 10c of the bottom plate 10. When such a recess is provided in the medial midfoot region 20, the bending rigidity of the medial midfoot region 20 can be reduced as compared to a case where no such recess is provided. "the bending rigidity of the medial midfoot region 20 is reduced by the concavity" means such a case. In the case where the concave portion is the inner lateral groove portion 34, the bending rigidity can be effectively reduced.

In detail, the "elongation property of the material constituting the base plate 10" herein means a young's modulus [ N/mm ] in the foot length direction X of the material constituting the base plate 10²]. The stiffness reduced portion 32 is formed using a second material having a lower young's modulus in the foot length direction X than that of the first material forming a portion adjacent to the stiffness reduced portion 32 of the base plate 10. This can reduce the bending rigidity of the inner midfoot region 20, as compared with the case where the rigidity reducing section 32 is formed of the first material. "the bending rigidity of the medial midfoot region 20 is reduced based on the elongation characteristics of the material constituting the chassis base 10" means such a case.

Further, a constricted portion 10f that is depressed outward in the foot width direction X is formed on the inner side edge 10c of the foot portion 14 in the floor. In many cases, the bending rigidity of the medial midfoot region 20 of the chassis 10 is less than the bending rigidity of the lateral midfoot region 22 due to the influence of the neckdown portion 10 f. In order to eliminate the influence of the constricted portion 10f, the shapes of the inner edge 10c and the outer edge 10d of the bottom plate 10 in plan view are removed from the factors that cause the aforementioned reduction in bending rigidity.

By providing such a rigidity reducing portion 32 in the medial midfoot region 20, the bending rigidity of the medial midfoot region 20 is more likely to be reduced than the bending rigidity of the lateral midfoot region 22, as compared with the case where no rigidity reducing portion 32 is provided. The bending rigidity of the medial midfoot region 20 is lower than the bending rigidity of the lateral midfoot region 22, and when the chassis 10 is bent and deformed about the foot width direction axis, the amount of extension in the foot length direction X of the ground contact surface of the medial midfoot region 20 can be made larger than the amount of extension of the lateral midfoot region 22. This means that the medial midfoot region 20 is more susceptible to stretch deformation in the foot length direction X, that is, to external twisting, than the lateral midfoot region 22 when the wearer is in a toe-in stance. In other words, the outer torsional resistance at the midfoot portion 14 can be reduced as compared with the case where the rigidity reducing portion 32 is not provided at the medial midfoot region 20. Therefore, by providing the rigidity reducing portion 32 in the medial midfoot region 20, the amount of external torsion is increased when the wearer twists the outside of the human midfoot in a toe-standing posture as compared to the case where the rigidity reducing portion 32 is not provided. As a result, the bone locking mechanism can be induced, and stability in the toe-standing posture and propulsive force during the kick-out operation can be improved.

The medial midfoot region 20 is configured to have a lower bending rigidity than the lateral midfoot region 22. This is achieved by providing the rigidity reduction portion 32 in the medial midfoot region 20 or by the shape of the medial edge 10c and the lateral edge 10d of the chassis 10 in plan view. These flexural rigidities can also be evaluated by the amount of strain in the foot length direction of the ground contact surface when a bending moment of a predetermined magnitude about the axis in the foot width direction is applied to the toe side end portion and the heel side end portion of the referred midfoot region in the top surface direction of the chassis. The larger the strain amount, the smaller the bending rigidity. The phrase "the bending stiffness of medial midfoot region 20 is less than the bending stiffness of lateral midfoot region 22" as used herein means that the amount of strain in medial midfoot region 20 is greater than the amount of strain in lateral midfoot region 22. The strain amount may be obtained by actually cutting the above-mentioned midfoot region from the bottom plate 10 and measuring the cut piece.

As described above, the line q indicates a site where the estimated transverse tarsal joint of the foot of the wearer is located. The more the rigidity-lowered part 32 is located near the line q, the more the midfoot portion 14 tends to be twisted outward at a position near the midtarsal joint Jc, and along with this, the bone lock mechanism is likely to be induced. Therefore, the rigidity reducing portion 32 is preferably provided in a region on the heel side of a straight line Y bisecting the entire length of the midfoot portion 14 in the foot length direction along the foot width direction Y, in the medial midfoot portion region 20 of the midfoot portion 14.

In addition, when the sole is in the toe-standing posture, a load of twisting the sole 10 outward is applied to the sole 10 via the upper surface of the shoe in a state where the forefoot portion 12 of the sole 10 is restrained. At this time, the toe side end of the foot section 14 is fixed in the bottom plate, and an external torsional load is applied to the heel side end thereof. At this time, the portion of the sole plate where the foot portion 14 is deformed to the maximum extent is the region of the sole plate 10 on the toe side of the foot portion 14 close to the constrained forefoot portion 12. In the region of the sole plate on the toe side of the foot section 14, the sole plate center section 14 can be effectively twisted outward by making the bending rigidity of the sole plate center section 14 on the inner side in the foot width direction different from the bending rigidity of the sole plate center section 14 on the outer side. Therefore, the rigidity reducing portion 32 may be preferably provided in a region on the toe side of a straight line y bisecting the foot portion 14 in the foot width direction in the floor.

Next, another condition that is preferably satisfied in increasing the external torsion amount at the foot in the human body will be described. When the wearer is in the toe-standing posture, a case may be considered in which an external twisting load for twisting the base plate 10 externally is applied to the base plate 10 via the upper surface of the shoe. Consider a case where a lateral groove portion is formed from the inner side edge 10c to the outer side edge 10d in the rear foot portion 16 of the bottom plate 10. In this case, even if the aforementioned external torsion load is applied to the sole plate 10, the bending deformation in the lateral groove portion of the rear foot portion 16 is dominant, and the amount of external torsion in the foot portion 14 in the sole plate becomes small. As a result, when the wearer attempts to twist the human midfoot outward in a toe-standing posture, the wearer receives resistance from parts other than the midfoot portion 14, and it is difficult to increase the amount of twist outward in the human midfoot portion.

Fig. 7 is a bottom view of the base plate 10 according to another embodiment of the present invention. In order to solve the above problem, as other conditions, the following conditions are set: a continuous surface 16c is formed on the ground plane of the base plate 10, and the continuous surface 16c is continuous in the foot length direction from the toe side end 16a to the heel side end 16b of the rear foot 16 of the base plate 10. In this figure, the range in which the continuous surface 16c is formed is indicated by hatching with a two-dot chain line. This means that no lateral groove portion is formed from the inner side edge 10c to the outer side edge 10d at the hindfoot portion 16 of the base plate 10. In the illustrated example, the continuous surface 16c is formed over the entire range in the foot width direction Y, but may be formed over at least a part of the range in the foot width direction Y.

Thus, when the wearer attempts to twist the midfoot portion outward in the toe-standing posture, the continuous surface 16c can suppress bending deformation in the hindfoot portion 16 of the chassis 10, and the outward twisting amount can be prevented from becoming smaller in the chassis midfoot portion 14 in accordance with the bending deformation. Accordingly, by satisfying the above-described conditions, the effect of reducing the external torsion resistance at the foot portion 14 in the floor is easily obtained, and the external torsion amount at the foot portion in the human body is easily increased.

In addition, in the case where a reinforcing member such as a shank (shank) is attached to the sole center foot 14, the bending rigidity of the sole is excessively increased, and the external torsional resistance of the sole center foot 14 is excessively increased. Therefore, in the sole of the present embodiment, it is preferable that no reinforcing member such as a shank is attached to the foot portion 14. Thereby, the situation in which the bending rigidity of the foot portion 14 in the floor is excessively increased is suppressed, and the external torsional resistance of the foot portion 14 in the floor is liable to be reduced.

The reinforcing member here is a member other than the midsole 56 and the outsole 58 of the base plate 10 described later. The reinforcing member is a member used for increasing bending rigidity around the axis of the sole in the foot width direction, such as a shank, and is formed using a material having a hardness greater than the maximum hardness of the bottom plate 10. The material is, for example, a synthetic resin of various metals and having a hardness of 80 degrees or more in JIS a hardness. The JIS a hardness here refers to a value measured and obtained by a type a durometer in accordance with JIS K6301. The hardness of the midsole 56 is, for example, 35 to 75 degrees in accordance with JIS C hardness, and the hardness of the outsole 58 is, for example, 50 to 75 degrees in accordance with JIS a hardness. The JIS C hardness here means a value measured and obtained by a type C durometer in accordance with JIS K6301.

In addition, when the reinforcing member is not attached to the floor center leg portion 14, the reinforcing member may be attached to the floor front leg portion 12 and the floor rear leg portion 16. With this structure, the external torsional resistance of the foot section 14 in the floor can be easily reduced.

Next, an analysis performed after considering the shoe sole of the embodiment will be described. Fig. 8 is a perspective view schematically showing a model in which the base plate 10 used for analysis is simulated. In this analysis, a base plate of the same size as the base plate 10 shown in fig. 7 was used. The bottom plate 10 has a total length La of 280mm and an entire width Lb of 200mm, and has a uniform thickness of 20 mm. The physical property condition of the base plate 10 is set to 6N/mm of Young's modulus²]Poisson ratio of 0.25-]Density 3X 10²[kg/m³]. This analysis envisages reproducing the deformation state of the base plate 10 in the plate supporting action. Therefore, the estimated region Sa where the big toe ball hits from the toe of the wearer is completely restrained, and an upward load Fz is applied to the hindfoot portion 16 of the chassis 10. In addition, in order to apply an external torsional load to the foot plate 10, a load Fy directed outward in the foot width direction Y is applied to the rear foot portion 16 of the foot plate 10.

Fig. 9 is a graph showing the analysis results. In this figure, the distribution of the maximum principal stress in the bottom surface of the soleplate 10 obtained under the aforementioned conditions is shown. The higher the density of dots, the higher the stress. It can be confirmed that: when an external torsional load is applied to the floor panel 10, the stress in the region 24 of the floor panel 10 including the medial midfoot region 20 and the peripheral region becomes greater than the stress in the other regions. This means that this area 24 offers a greater resistance to external twisting of the foot 14 in the sole plate. Thus, it is possible to consider: by providing the rigidity reducing portion 32 in the region 24 where resistance is expected to be given to the external torsion of the foot portion 14 in the floor (hereinafter referred to as the external torsion resistance expected region 24), the external torsion at the foot portion 14 in the floor can be effectively reduced. Therefore, the outer torsional resistance assumed region 24 obtained by this analysis is used as a region where the stiffness reduced portion is preferably provided.

Fig. 10 is a diagram for explaining the external torsional resistance assumed region 24. The outer torsional resistance conceived area 24 is geometrically defined in relation to the shape of the base plate 10. Hereinafter, the positional relationship of the base plate 10 in a plan view will be described as a reference.

The definition of the lines s, p, q is the same as described above. The area of the bottom plate 10 closer to the heel side than the line q is divided into 0.2: a line of 0.9 along the foot width direction Y is defined as a line r. A straight line obtained by rotating the line p in the outward direction Pa, which is a direction in which the toe side is rotated outward in the foot width direction, by 13 degrees around the point o1, as viewed from a point o1 which is an intersection of the line p and the line s, is defined as a line t. A straight line obtained by rotating the line s 8 degrees in the above-described outward direction Pa on the toe side as viewed from a point o1 which is an intersection of the line s and the line p is defined as a line u. A straight line obtained by rotating line q in the outward direction Pa by 5 degrees around point o2 when viewed from point o2, which is the intersection of line u and line q, is defined as line v. A straight line obtained by rotating line r outward Pa about point P by 4 degrees as viewed from point P, which is the intersection of line r and line u, is defined as line w. A straight line connecting a point o5 and a point o2, which are intersections of the inner edges 10c of the bottom plate 10 and the line w, is defined as a line x.

At this time, the outer torsional resistance assumed region 24 is set to be a first region 26 surrounded by the line t, the line u, the line v, and the inner edge 10c of the bottom plate 10. The external torsional resistance assumed region 24 is provided on the ground contact surface of the chassis 10 in a plan view of the chassis 10. The rigidity reducing portion 32 is preferably provided in the outer torsional resistance assumed region 24. It is considered that the rigidity reducing portion 32 is provided in the outer torsional resistance assumed region 24, whereby the outer torsional resistance of the foot portion 14 in the floor can be effectively reduced.

The rigidity reducing portion 32 may be provided in a region belonging to the outer torsional resistance assumed region 24 outside the region of the medial midfoot region 20 (region of the range S1), in addition to the region belonging to the outer torsional resistance assumed region 24 in the medial midfoot region 20. The rigidity reducing portion 32 provided in a portion belonging to the external torsion resistance assumed region 24 outside the range of the inner middle foot region 20 also reduces the bending rigidity of the portion of the floor panel due to the aforementioned recessed portion opened in the ground contact surface of the floor panel 10, the elongation characteristics of the material constituting the floor panel 10, and the like.

Referring to the analysis results of fig. 9, the first region 26 of the bottom plate 10 set as the outer torsional resistance assumed region 24 largely increases mainly in the direction Lb toward the heel side in the foot length direction Lx. The first region 26 is also slightly enlarged in a direction Lc outward in the foot width direction Y. The analysis contemplates a flat panel support action, but in other actions such as running, it is contemplated that a greater external torsional load will be applied to the deck 10. When a large load is applied to the bottom plate 10, it is considered that the outer torsional resistance assumed region 24 first becomes larger in the direction Lb toward the heel side in the foot length direction Lx. In addition, it is considered that: the external torsional resistance expected area 24 becomes larger in the direction Lc toward the outer side in the foot width direction Y to a smaller extent than in the heel side in the foot length direction Lx.

Therefore, as shown in fig. 10, the outer torsional resistance assumed region 24 may be configured by a first region 26 and a second region 28 in a plan view, and the second region 28 may be surrounded by the line v, the line x, and the inner edge 10c of the bottom plate 10. By providing the rigidity reducing portion 32 in such an external torsional resistance assumed region 24, the external torsional resistance of the foot portion 14 in the floor can be reduced more effectively in the case where a large external torsional load is applied to the floor 10.

The rigidity reducing section 32 may be provided in a region belonging to the outer torsional resistance assumed region 24 outside the region of the medial midfoot region 20 (region S1, region S2) in addition to the region belonging to the outer torsional resistance assumed region 24 in the medial midfoot region 20.

The outer torsional resistance assumed region 24 may be defined by a first region 26, a second region 28, and a third region 30 in a plan view, and the third region 30 is defined by a line s, a line u, a line x, and a line w. By providing the rigidity reducing portion 32 in the external torsional resistance assumed region 24, the external torsional resistance of the foot portion 14 in the floor can be reduced more effectively when a greater external torsional load is applied to the floor 10.

The rigidity reducing section 32 may be provided in a region belonging to the outer torsional resistance assumed region 24 outside the region of the medial midfoot region 20 (regions of ranges S1, S2, S3) in addition to the region belonging to the outer torsional resistance assumed region 24 in the medial midfoot region 20.

Next, the effects of the invention due to the presence or absence of the above-described conditions will be described using an analysis. Fig. 11 shows a base plate 100 of a reference example for analysis. The base plate 10 of the embodiment is shown in fig. 7. The dimensional conditions and physical property conditions of the

base plates

10 and 100 are set to be the same as those in the analysis of fig. 8.

Both the base plate 100 of the reference example and the base plate 10 of the embodiment are provided with the lateral groove portions 40 at the portions of the forefoot portion 12 of the base plate corresponding to the MP joints so as to be bent around the foot width direction axis at the forefoot portion 12 of the base plate in the toe standing posture. In the bottom plate 10 of the embodiment, two inner lateral groove portions 34 are provided as the rigidity reducing portion 32 that reduces the bending rigidity of the inner midfoot region 20. In the bottom plate 10 of the embodiment, another inner lateral groove portion 34 is provided as the rigidity reducing portion 32 that reduces the bending rigidity of the outer torsional resistance assumption region 24 at the portion S1 outside the range of the inner midfoot region 20. Three inner lateral groove portions 34 extend in the foot width direction Y from the inner edge 10c of the bottom plate 10 and are provided at intervals in the foot length direction Lx. The same rigidity reducing portion 32 is not provided in the foot portion 14 in the floor of the reference example.

The deformation characteristics of the

base plates

10 and 100 against the external torsion were evaluated by eigenvalue analysis. Specifically, a torsional frequency, which is a natural frequency when the natural vibration mode of the

bottom plate

10 or 100 becomes torsional vibration, is obtained by the eigenvalue analysis, and the deformation characteristics of the

bottom plate

10 or 100 are evaluated using the torsional frequency. The smaller the torsional frequency, the smaller the external torsional resistance of the

base plate

10, 100.

Fig. 12 is a graph showing the torsional frequency obtained by this analysis. As shown in the drawing, the base plate 10 of the embodiment has a lower torsional frequency than the base plate 100 of the reference example. This means that the external torsion resistance of the base plate 10 of the embodiment is smaller than that of the base plate 100 of the reference example.

Next, the effects of the invention due to the presence or absence of the above-described conditions will be described using experimental examples. In this experiment, the same size and physical properties of the two types of substrates shown in fig. 7 and 11 were used. In this experiment, shoes using these soles were worn. The shoe was worn and consciously held in the following position for 40 seconds: the wearer's elbows are grounded and the forefoot 12 of the sole plate is grounded, the torso floats from the ground, and the head is in a straight position to the heel.

The results of this experiment were evaluated using the degree of torsion of the foot 14 in the baseplate and the amount of roll of the wearer's ankle. The torsion angle is measured by acquiring three-dimensional positional information of markers attached to a plurality of portions of the base plate 10 using a motion capture system. The twist angle is defined as the angle of the foot ground plane in the chassis relative to the rear foot ground plane of the chassis. Similarly to the torsion angle, the amount of ankle swing of the wearer is also measured by acquiring three-dimensional position information of the marker attached to the ankle.

Fig. 13(a) shows the measurement results of the torsion angle obtained by the experiment, and fig. 13(b) shows the measurement results of the ankle sway amount. It can be confirmed that the floor panel 10 of the embodiment has a larger torsion angle of the foot portion 14 than the floor panel 100 of the reference example. Thus, it can be confirmed that the outer torsional resistance of the base plate 10 of the example is smaller than that of the base plate 100 of the reference example. In addition, it can be confirmed that the swing amount of the ankle is smaller in the bottom plate 10 of the embodiment than in the bottom plate 100 of the reference example. This confirmed that the shoe using the base plate 10 of the example can obtain good stability in the toe-standing posture. As previously mentioned, this is due to the fact that as the twist angle of the foot 14 in the sole plate increases, a bone locking mechanism can be induced.

Fig. 14 is a bottom view of the base plate 10 according to the first modification. In the bottom plate of the bottom plate 10 of the first modification, the foot portion 14 and the rear foot portion 16 are formed with outer lateral groove portions 44, and the outer lateral groove portions 44 are opened in the ground contact surface 10e of the bottom plate 10 and extend in the foot width direction Y from the outer edge 10d of the bottom plate 10. In this case, the bending rigidity is reduced in a range of the bottom plate 10 including the lateral midfoot region 22. Accordingly, it is difficult to form a sufficient difference in bending rigidity between the inner midfoot region 20 and the outer midfoot region 22 of the chassis 10. The larger this difference in bending rigidity is, the more preferable in terms of sufficiently obtaining the effect of reducing the external torsional resistance in the foot portion 14 in the floor.

Therefore, it is preferable that the lateral groove portion 44 extending in the foot width direction Y from the outer side edge 10d of the base plate 10 is not formed in a part of the range Sb in the foot length direction X of the base plate 10. The partial range Sb includes: all of the ranges Sb1 in the foot length direction X of the stiffness reduced portion 32 and all of the ranges Sb2 on the heel side of the range Sb1 are provided. This makes it easy to form a sufficient difference in bending rigidity between the medial midfoot region 20 and the lateral midfoot region 22 of the chassis 10, and to obtain an effect of reducing the external torsional resistance of the chassis at the midfoot portion 14. From the same viewpoint, it can be said that it is preferable not to form the outer lateral groove portion 44 in the range Sc closer to the heel side than the line y.

(first embodiment)

Fig. 15 is a side view of a shoe 52 using the sole 50 of the first embodiment, as viewed from the medial side in the foot width direction. The shoe 52 is used for indoor sports such as a gym, but its use is not particularly limited. The shoe 52 includes: a sole 50 supporting a foot of a wearer; and an upper 54 that wraps the foot of the wearer.

The shoe sole 50 includes a bottom plate 10. The bottom plate 10 of the present embodiment includes a midsole 56. The chassis 10 has a ground surface 10e that contacts a road surface. The ground plane 10e of the present embodiment constitutes the lower surface of the midsole 56. The midsole 56 mainly has a function of relaxing a striking impact. The midsole 56 is formed using, for example, a resin foam or a non-foam.

Fig. 16 is a bottom view of the base plate 10. A plurality of inner lateral groove portions 34 are formed in the bottom plate 10. The plurality of inner side horizontal groove portions 34 are formed to be opened in the ground surface 10e of the base plate 10 and to extend in the in-plane direction of the ground surface 10 e. The plurality of inner side transverse groove portions 34 extend in the foot width direction Y from the inner side edge 10c toward the outer side edge 10d side of the bottom plate 10. The plurality of inner lateral groove portions 34 are provided at intervals in the foot length direction Lx. The end portions of the inner lateral groove portions 34 on the outer side in the foot width direction Y are provided at intermediate positions in the foot width direction Y of the bottom plate 10.

The extending direction of the inner side lateral groove portion 34 is set to a direction inclined with respect to the foot width direction axis. Specifically, the direction is set to be the same as the direction along the line t in a plan view. As shown in fig. 2, the direction along the line t is the same direction as the direction along a straight line Ld that connects the rear end of the first metatarsal bone Bf1 and the rear end of the fifth metatarsal bone Bf5 directly from the rear end of the first metatarsal bone Bf1 that constitutes the tarsometatarsal joint Jb. The term "identical" as used herein includes both cases where they are literally identical and cases where they are substantially identical. In the case where this condition is satisfied, the heel side end of the soleplate 10 is liable to be directed toward the outward turning direction, with the result that the foot 14 in the soleplate can be easily twisted outward.

From the viewpoint of effectively reducing the bending rigidity of the inner midfoot region 20 of the bottom plate 10, the deeper the depth of the inner lateral groove portion 34 from the ground surface 10e is, the more preferable. From this viewpoint, the depth of the inner lateral groove portion 34 is preferably 1% or more, more preferably 5% or more, and particularly preferably 10% or more, with respect to the entire average thickness of the bottom plate 10.

The groove width of the inner lateral groove portion 34 is preferably 1mm or more. The groove width here means the opening width of the inside horizontal groove portion 34 in the ground surface 10e of the chassis 10. The reason why the groove width is set to 1mm or more is to effectively reduce the bending rigidity of the inner midfoot region 20 of the chassis 10. The upper limit of the groove width is not particularly limited, but is preferably 20mm or less, for example.

The shape of the inner lateral groove portion 34 is an example of a straight line shape extending in the in-plane direction, but is not limited thereto. For example, the shape may be a curved shape extending in the in-plane direction, a shape combining a straight line and a curved line, or the like.

The plurality of inner lateral groove portions 34 respectively constitute a rigidity reducing portion 32 that reduces the bending rigidity of the inner midfoot region 20. The rigidity reducing portion 32 is provided in plurality. One inside lateral groove portion 34 of the inside lateral groove portions 34 that is a part of the plurality of inside lateral groove portions 34 is formed so as to straddle the inside midfoot region 20 to the outside midfoot region 22. In this way, although it is assumed that the rigidity reducing portion 32 is provided in the medial midfoot region 20, it may be provided so that a part thereof is exposed in the lateral midfoot region 22. The rigidity reducing portions 32 are formed so as to be located in the first region 26, the second region 28, and the third region 30 of the outer torsional resistance expected region 24, respectively. When the rigidity reducing portion 32 is provided in the outer torsional resistance assumed region 24 in this manner, the rigidity reducing portion may be provided beyond the outer torsional resistance assumed region 24.

(second embodiment)

Fig. 17 is a bottom view of the base plate 10 according to the second embodiment. Fig. 18(a) is a side view of the base plate 10 as viewed from the inside in the foot width direction, and fig. 18(b) is a side view of the base plate 10 as viewed from the outside in the foot width direction.

The bottom plate 10 of the second embodiment has, in addition to the plurality of inner lateral groove portions 34, longitudinal groove portions 36 extending in the foot length direction X. The vertical groove portion 36 is opened in the ground surface 10e of the base plate 10. The longitudinal groove portion 36 is continuous with the respective foot width direction outer side end portions of the plurality of inner lateral groove portions 34. The longitudinal groove portion 36 of the present embodiment is provided so as to be located in the medial midfoot region 20, and is not provided in the lateral midfoot region 22.

The vertical groove portion 36 of the present embodiment has: a heel side portion 36b provided closer to the heel side than the midway portion 36a in the foot length direction X; and a toe portion 36c provided on the toe side of the halfway portion 36 a. The middle portion 36a of the vertical groove portion 36 of the present embodiment is provided so as to be convex outward in the foot width direction. The heel side portion 36b is obliquely disposed with respect to the foot length direction axis as it approaches the medial edge 10c of the baseplate 10 toward the heel side of the baseplate 10. The distal end of heel side portion 36b is connected to the medial edge 10c of the bottom plate 10. The toe side portion 36c is provided obliquely to the foot length direction axis so as to approach the inner edge 10c of the base plate 10 as it goes toward the toe side of the base plate 10. The distal end of toe portion 36c is connected to the medial edge 10c of base plate 10. The longitudinal groove portion 36 is provided in such a manner that a part of the range from the halfway portion 36a thereof toward the heel side overlaps with the line u.

In the inner midfoot region 20 of the bottom plate 10, a plurality of island regions 38 surrounded by a plurality of inner lateral groove portions 34, a plurality of longitudinal groove portions 36, and the inner edge 10c of the bottom plate 10 are formed. The island-like region 38 is divided with respect to the other regions of the bottom plate 10 including the outer midfoot region 22 by a groove portion including the longitudinal groove portion 36. The "groove portion including the longitudinal groove portion 36" in the present embodiment refers only to the longitudinal groove portion 36. In the case where the longitudinal groove portion 36 is not connected to the medial edge 10c of the sole plate 10, a medial lateral groove portion 34 on the most toe or heel side is also included. It can be said that the island region 38 is divided with respect to the region comprising the lateral midfoot region 22 by the groove portion here comprising the longitudinal groove portion 36.

Accordingly, in the portion where the plurality of inner lateral groove portions 34 are formed, when the inner midfoot region 20 is bent and deformed, the influence of the deformation of the plurality of inner lateral groove portions 34 can be prevented from being propagated from the longitudinal groove portions 36 to the outer midfoot region 22 side position. Accordingly, it is easy to design so that the bending stiffness of medial midfoot region 20 differs from the bending stiffness of lateral midfoot region 22.

Further, the groove width of the longitudinal groove portion 36 is set larger than the groove width of the inner lateral groove portion 34. The inner lateral groove portion 34 on the most toe side connected to the end portion of the longitudinal groove portion 36 is also set to have a larger groove width than the other inner lateral groove portions 34.

The front and

middle leg portions

12 and 14 of the bottom plate 10 of the second embodiment are formed with a plurality of second lateral groove portions 42. The plurality of second horizontal groove portions 42 are provided at intervals in the foot length direction Lx. A part of the second horizontal groove portions 42 of the plurality of second horizontal groove portions 42 is provided so as to extend from the outer edge 10d to the inner edge 10c of the bottom plate 10. The other second horizontal groove portions 42 of the plurality of second horizontal groove portions 42 are provided so as to extend from the outer edge 10d to the inner edge 10c side of the bottom plate 10. The other second horizontal groove portion 42 has an end portion provided at a halfway position in the foot width direction of the bottom plate 10. Any one of the second horizontal groove portions 42 is provided at a toe side position with respect to the aforementioned line y.

Fig. 19(a) is a bottom view of the bottom plate 10 of the second modification. Fig. 19(b) is a bottom view of the bottom plate 10 of the third modification. Fig. 19(c) is a bottom view of the bottom plate 10 of the fourth modification. An example in which both end portions of the vertical groove portion 36 are connected to the inner edge 10c of the bottom plate 10 in the example of fig. 17 is explained. Both end portions of the vertical groove portion 36 in this example are provided at positions apart from the inner edge 10c of the bottom plate 10 in the foot width direction. In the present example, the longitudinal groove portion 36 has its end connected to the end of the inner lateral groove portion 34 so as to form a corner portion with the inner lateral groove portion 34. The end of the vertical groove 36 may be disposed so as to end without being connected to another groove.

Fig. 19(a) shows an example in which a single vertical groove portion 36 is provided, and fig. 19(B) shows an example in which a plurality of vertical groove portions 36-a and 36-B (hereinafter, these will be collectively referred to as vertical groove portions 36) are provided. The plurality of longitudinal groove portions 36-A, 36-B include a first longitudinal groove portion 36-A on the outside in the foot width direction and a second longitudinal groove portion 36-B on the inside in the foot width direction. The first longitudinal groove portions 36-a are provided in such a manner as to be connected to the end portions of the plurality of inner lateral groove portions 34. The second longitudinal groove portion 36-B is provided so as to intersect and be continuous with a middle portion of the plurality of inner lateral groove portions 34 in a T-shape or an X-shape.

Fig. 19(a) and 19(b) show an example in which the vertical groove portion 36 is provided to extend linearly along the line s, and fig. 19(c) shows an example in which the vertical groove portion 36 is provided to extend linearly along the line u. The term "linear" as used herein means a shape that follows a straight line, and does not mean a geometrically strictly linear shape. In this manner, the extending direction Pb in which the linear longitudinal groove portion 36 extends from the toe side toward the heel side is set such that the angle formed by the direction axis with respect to the line s is, for example, 0 ° to 15 °.

(third embodiment)

Fig. 20 is a side view of the shoe sole 50 of the third embodiment as viewed from the same point of view as fig. 15. In the above embodiment, the example of the base plate 10 having only the midsole 56 is described, and the outsole 58 may be provided.

The outsole 58 is disposed below the midsole 56, and is attached to the lower surface of the midsole 56 by bonding or the like. The ground contact surface 10e of the base plate 10 constitutes the lower surface of the outsole 58. The outsole 58 mainly has a function of ensuring grip with respect to a road surface. The outsole 58 is formed using, for example, a rubber non-foam or foam. The midsole 56 is formed thicker than the outsole 58 from the viewpoint of functioning to moderate the impact of landing. The outsole 58 may have a hardness greater than that of the midsole 56, because it functions to ensure grip. The inner lateral groove portion 34 of the present embodiment is formed within a range not reaching the midsole 56 from the ground contact surface 10e of the outsole 58.

(fourth embodiment)

Fig. 21 is a side view of the shoe sole 50 of the fourth embodiment as viewed from the same point of view as fig. 15. Unlike the example of fig. 20, the inner lateral groove portion 34 of this example is formed in a range from the ground contact surface 10e of the outsole 58 to the midsole 56.

As such, the sole plate 10 may have either or both of the midsole 56 and the outsole 58. For example, although not shown, the base plate 10 may have only the outsole 58.

The embodiments of the present invention have been described in detail above. The above embodiments are merely illustrative of specific examples for carrying out the invention. The contents of the embodiments do not limit the protection scope of the present invention, and various design changes such as modification, addition, deletion, and the like of the constituent elements can be made without departing from the scope of the inventive concept defined in the claims. In the above-described embodiments, the contents of which the design change can be made are described by referring to the expressions "in the embodiment", "in the embodiment" and the like, but the contents without such expressions do not allow the design change. Note that the hatching given to the cross section of the drawings does not limit the material of the object to which the hatching is given.

The "foot length direction Lx" may Be set along a straight line which is assumed to Be located on the bottom plate 10 in design and which connects the toe-side end of the second toe of the foot of the wearer to the rearmost end of the calcaneus Be (calcaneus emius arch) from the toe-side end of the second toe.

The bottom plate center line s may be obtained by dividing the entire width Lb of the bottom plate 10 into 1: 1, extending along the foot length direction Y. From another viewpoint, the entire width Lb of the bottom plate 10 may be divided into 1: 1-3.7: 3.2 along the foot length direction Y.

The midsole 56 may be formed by stacking two or more components having different material properties in the vertical direction or by arranging them in the foot length direction.

Industrial applicability

The present invention relates to a sole for a shoe.

Claims

1. A shoe sole having a bottom plate, wherein,

the chassis has a rigidity reducing portion provided in a medial midfoot region when a midfoot of the chassis is divided into the medial midfoot region and a lateral midfoot region on both sides in a foot width direction by a predetermined chassis center line,

the rigidity reducing portion reduces the bending rigidity of the medial midfoot region based on another element different from the shape of the medial and lateral edges of the bottom plate in a plan view so that the bending rigidity of the medial midfoot region about the axis in the foot width direction is smaller than the bending rigidity of the lateral midfoot region about the axis in the foot width direction.

2. The shoe sole of claim 1,

the other element is one or a combination of two of a recess opened in the ground contact surface of the chassis and an elongation property of a material constituting the chassis.

3. The shoe sole of claim 2,

in the case where the other element has a recess opened in the ground plane of the chassis,

the rigidity reducing portion has an inner side horizontal groove portion that is open in the ground contact surface of the bottom plate and extends in the foot width direction from the inner side edge.

4. The shoe sole of claim 3,

a plurality of inner side horizontal groove portions are formed,

the rigidity reducing portion further has a longitudinal groove portion which is opened in the ground contact surface of the bottom plate, extends in the foot length direction, and is connected to end portions in the foot width direction of the plurality of inner lateral groove portions.

5. The shoe sole of claim 2,

in the case where the other element has the elongation property of the raw material constituting the bottom plate,

the elongation characteristic of the raw material is a Young's modulus in a foot length direction of the raw material constituting the base plate,

the stiffness reduced portion is made of a material having a Young's modulus in the foot length direction X smaller than that of the material constituting the portion adjacent to the stiffness reduced portion in the foot length direction X.

6. The shoe sole according to any one of claims 1 to 5,

in a top view of the base plate,

dividing the total length La of the sole plate in the foot length direction from the toe side to the heel side into 1.5: 1.0: 1.1 are defined as a line p and a line q,

the width Lb of the bottom plate in the foot width direction is divided into 1.2 parts from the inside toward the outside in the foot width direction: 1.0 is a line s which becomes the center line of the base plate,

a straight line obtained by rotating the line p in an outward direction, which is a direction in which the toe side is rotated outward in the foot width direction, by 13 degrees around the point O1 as viewed from a point O1 which is an intersection of the line p and the line s is a line t,

a straight line obtained by rotating the line s in the outward direction by 8 degrees around the point O1 when viewed from the point O1 is defined as a line u,

a straight line obtained by rotating the line q in the outward direction by 5 degrees around the point O2 as viewed from a point O2 which is an intersection of the line u and the line q is defined as a line v,

a region surrounded by the line t, the line u, the line v, and the inner edge is set as a first region,

when the region constituted by the first region is set as the outer torsional resistance assumed region,

the rigidity reducing portion is provided in the outer torsional resistance assumed region.

7. The shoe sole according to any one of claims 1 to 5,

in a top view of the base plate,

dividing the total length La of the sole plate in the foot length direction from the toe side to the heel side into 1.5: 1.0: 0.2: 0.9 is defined as a line p, a line q and a line r along the foot width direction,

a straight line obtained by rotating the line r in the outward direction by 4 degrees around a point P as viewed from the point P at which the line r intersects with the line u is defined as a line w,

a straight line connecting the point O2 and a point O5 which is an intersection of the inner edge and the line w is defined as a line x,

setting a region surrounded by the line v, the line x, and the inner edge as a second region,

when a region constituted by the first region and the second region is set as an external torsional resistance assumed region,

8. The shoe sole according to any one of claims 1 to 5,

in a top view of the base plate,

a region surrounded by the line s, the line u, the line x, and the line w is set as a third region,

when a region including the first region, the second region, and the third region is an assumed external torsional resistance region,

9. The shoe sole according to any one of claims 1 to 5,

a continuous surface is formed on the ground plane of the base plate, and the continuous surface is continuous along the length direction of the foot from the toe side end to the heel side end of the rear foot part of the base plate.

10. The shoe sole according to any one of claims 1 to 5,

an outer lateral groove portion that is open to the ground plane of the bottom plate and extends in the foot width direction from the outer edge is not formed in a range in the foot length direction in which the rigidity reducing portion is provided and a range in the foot length direction on the heel side than the range.

11. The shoe sole according to any one of claims 1 to 5,

the sole plate has either or both of a midsole and an outsole,

no reinforcing member is attached to the midfoot portion of the chassis.

12. A shoe having the sole according to any one of claims 1 to 11.