Patent Description:
When a human runs, the foot falls inward at the same time as landing, and the medial longitudinal arch of the foot collapses. This series of foot movements is also called pronation and is known as natural foot movements for dispersing an impact during landing. However, if the foot falls too far inward, that is, overpronation occurs, the landing tends to be unstable, applying a greater strain to the leg muscles, joints, and knees.

For this reason, conventional techniques for controlling excessive pronation are known (see, for example, <CIT>- <CIT> and <CIT>). <CIT> discloses a shoe sole including a body portion and a heel holding portion. The heel holding portion is located opposite to a ground contact surface of the body portion and holds a heel portion of a foot at least from a medial foot side. The body portion includes a low hardness portion and a high hardness portion. The high hardness portion is made of a foam material harder than a foam material of the low hardness portion. The heel holding portion is made of a resin harder than each of the foam material of the low hardness portion and the foam material of the high hardness portion. On the medial foot side in a rear foot portion, the low hardness portion is located between the heel holding portion and the high hardness portion in an up-down direction. <CIT> discloses a shoe sole, in which a forefoot supporting part for supporting the forefoot part of the foot of a wearer, a midfoot supporting part for supporting the midfoot part of the foot, and a rearfoot supporting part for supporting the rearfoot part of the foot are connected in this order from the front. The shoe sole comprises a midsole having cushioning properties. The midsole comprises: a cushioning part formed from a first foam material; and a distortion suppressing part formed from a harder material than the first foam material. The distortion suppressing part comprises: a first part that extends at least over the entire midfoot supporting part in the front-back direction at the inner foot side; and a second part that extends obliquely backward from the first part toward the outer foot side. <CIT> discloses a shoe, which has a forefoot portion, a midfoot portion, and a heel portion and comprises a sole having a base layer, a heel pedestal extending from the base layer, a lateral stabilizer pedestal extending from the base layer and positioned at least partially beneath the cuboid bone, and a medial stabilizer pedestal extending from the base layer and positioned at least partially beneath the navicular bone. During bipedal locomotion, the weight of a person wearing the shoe is supported on at least one of the heel pedestal, the lateral stabilizer pedestal, and the medial stabilizer pedestal, thereby transferring the person's weight from the heel pedestal, to the lateral stabilizer pedestal, and to the medial stabilizer pedestal. The heel pedestal, the lateral stabilizer pedestal, and the medial stabilizer pedestal include an outsole and a compressible base layer between the outsole and the wearer's foot.

However, the shoes disclosed in <CIT>- <CIT> and <CIT> do not consider overpronation under increased fatigue due to running.

The present invention has been made in view of the above, and it is an object of the present invention to further develop a sole of a shoe according to the preamble of claim <NUM> such that it is capable of controlling overpronation under increased fatigue due to running.

This object is achieved by a sole of a shoe having the features of claim <NUM>. Advantageous further modifications are defined in the dependent claims. A shoe having such sole is set out in claim <NUM>.

Hereinafter, embodiments of a sole of a shoe and a shoe according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited by the embodiments. In the following description, the same portions are denoted by the same reference signs, and redundant description will be omitted.

<FIG> is a bottom view of a shoe <NUM> according to a first embodiment of the present invention. In the drawings including <FIG>, only the shoe <NUM> for a left foot is illustrated. Since the shoe <NUM> has a left-right symmetrical structure for a left foot and a right foot, only the shoe <NUM> for a left foot is described in the present embodiment, and the description of the shoe <NUM> for a right foot is omitted. In the following description, a direction in which a shoe center axis C, which is a perpendicular line passing through the center of shoe <NUM> in a bottom view of the shoe <NUM>, extends is referred to as a front-rear direction, and a direction orthogonal to the front-rear direction in the bottom view of the shoe <NUM> is referred to as a foot width direction.

In the following description, a direction from the heel toward the toe of the shoe <NUM> in the front-rear direction is referred to as a front, and a direction from the toe toward the heel of the shoe <NUM> in the front-rear direction is referred to as a rear.

In the following description, a median side of a foot in the anatomical position is referred to as a medial foot side, and the side opposite to the median side of the foot in the anatomical position is referred to as a lateral foot side. That is, the side closer to the median line in the anatomical position is referred to as the medial foot side, and the side farther from the median line in the anatomical position is referred to as the lateral foot side.

In the following description, a vertical direction means a direction orthogonal to both the front-rear direction and the foot width direction unless otherwise specified.

A sole <NUM> includes a forefoot support portion R1 that supports the forefoot of a foot of a wearer with a standard body shape, a midfoot support portion R2 that supports the midfoot of a foot of a wearer with a standard body shape, and a rearfoot support portion R3 that supports the rearfoot of a foot of a wearer with a standard body shape. The forefoot support portion R1, the midfoot support portion R2, and the rearfoot support portion R3 are connected in order from the front side toward the rear side of the sole <NUM>.

A line along the foot width direction passing through a position corresponding to about <NUM>% of the dimension of the sole <NUM> from the front end of the sole <NUM> in the front-rear direction is defined as a first boundary line S1, and a line along the foot width direction passing through a position corresponding to about <NUM>% of the dimension of the sole <NUM> from the front end of the sole <NUM> in the front-rear direction is defined as a second boundary line S2. The first boundary line S1 is a line roughly along the MP joint of a wearer with a standard body shape. The second boundary line S2 is a line roughly along the Chopart joint of a wearer with a standard body shape. The forefoot support portion R1 is positioned in front of the first boundary line S1. The midfoot support portion R2 is positioned between the first boundary line S1 and the second boundary line S2. The rearfoot support portion R3 is positioned behind the second boundary line S2.

<FIG> is a medial-foot-side side view of the shoe <NUM> according to the first embodiment of the present invention. The shoe <NUM> is preferably a running shoe but may be a shoe for other sports, a walking shoe, a climbing shoe, or the like. The shoe <NUM> includes an upper <NUM> and the sole <NUM>.

The upper <NUM> is positioned above the sole <NUM>. The upper <NUM> includes an upper body <NUM>, a shoe tongue <NUM>, and a shoelace <NUM>.

The upper body <NUM> covers an instep side part of a foot of a wearer. The upper body <NUM> is formed with a foot insertion opening 20a and a throat portion 20b at its upper portion. The foot insertion opening 20a is an opening for inserting the foot of the wearer into the upper body <NUM>. The throat portion 20b is an opening communicating with the foot insertion opening 20a and extending to the front side from the foot insertion opening 20a. On both side edges of the throat portion 20b in the foot width direction, a plurality of string passing portions 20c spaced apart from each other in the front-rear direction is provided. <FIG> illustrates only the string passing portions 20c provided on the medial-foot-side side edge of the throat portion 20b. The string passing portions 20c are only required to allow the shoelace <NUM> to pass through. The string passing portions 20c are, for example, through holes that pass through the upper body <NUM> in the vertical direction.

The shoe tongue <NUM> is a member for protecting the instep of the wearer. The shoe tongue <NUM> covers the throat portion 20b inside the upper body <NUM>. The shoe tongue <NUM> is fixed to the upper body <NUM> by stitching, welding, bonding, or a combination thereof. The material of the upper body <NUM> and the shoe tongue <NUM> is, for example, woven fabric, knitted fabric, synthetic leather, or resin. In the shoe <NUM> required to have air permeability and lightweight property, the material of the upper body <NUM> and the shoe tongue <NUM> is preferably a double raschel warp knitted fabric knitted with polyester yarn. Note that the material of the upper body <NUM> and the shoe tongue <NUM> is not limited to those exemplified.

The shoelace <NUM> is a string-like member that is alternately passed through the string passing portions 20c provided at one side edge of the throat portion 20b in the foot width direction and the string passing portions 20c provided at the other side edge in the foot width direction. The shoelace <NUM> is detachably attached to the upper body <NUM>.

In the present embodiment, the upper <NUM> including the shoe tongue <NUM> and the shoelace <NUM> is described as an example, but the upper <NUM> may have a monosock structure in which a portion corresponding to the shoe tongue <NUM> is integrated with an ankle portion of the upper body <NUM>. In addition, a hook-and-loop fastener may be used instead of the shoelace <NUM> to bring the upper body <NUM> into close contact with the foot. If a hook-and-loop fastener is used to bring the upper body <NUM> into close contact with the foot, the string passing portions 20c are not formed in the upper body <NUM>.

The sole <NUM> is positioned below the upper <NUM>. The sole <NUM> covers the sole of the wearer. The sole <NUM> is fixed to the upper <NUM> by stitching, welding, bonding, or a combination thereof. The sole <NUM> includes an outsole <NUM> and a midsole <NUM>. The sole <NUM> includes an inner sole (not illustrated) that covers the lower opening of the upper body <NUM>. The inner sole is fixed to the upper surface of the midsole <NUM> by bonding or welding. The inner sole is fixed to the lower edge of the upper body <NUM> by stitching. Although not illustrated, the shoe <NUM> may include an insole. If the shoe <NUM> includes an insole, the insole is installed on the sole <NUM> inside the upper <NUM>. The sole <NUM> may have a structure in which the inner sole is omitted.

The midsole <NUM> is positioned on the upper surface of the outsole <NUM>. The midsole <NUM> is positioned between the upper <NUM> and the outsole <NUM>. The midsole <NUM> is a soft member having a smaller Young's modulus than the outsole <NUM>. The midsole <NUM> has a cushioning property. The midsole <NUM> is disposed over the entire region of the forefoot support portion R1, the midfoot support portion R2, and the rearfoot support portion R3. The midsole <NUM> has a first midsole portion <NUM> and a second midsole portion <NUM>. Note that, in <FIG>, the first midsole portion <NUM> is diamondhatched, and the second midsole portion <NUM> is dot-hatched in order to facilitate understanding.

The second midsole portion <NUM> is formed separately from the first midsole portion <NUM>. The second midsole portion <NUM> is fixed to the first midsole portion <NUM> by welding, adhesion, or a combination thereof. The hardness of the second midsole portion <NUM> is lower than the hardness of the first midsole portion <NUM>. By making the material of the first midsole portion <NUM> different from the material of the second midsole portion <NUM>, The hardness of the first midsole portion <NUM> and the hardness of the second midsole portion <NUM> can be made different. The material of the first midsole portion <NUM> and the material of the second midsole portion <NUM> are, for example, a resin foam material and a rubber foam material.

The first midsole portion <NUM> is disposed over the entire region of the forefoot support portion R1, the midfoot support portion R2, and the rearfoot support portion R3. The second midsole portion <NUM> is disposed below a portion of the first midsole portion <NUM> positioned in the midfoot support portion R2. Specifically, a cutout 32a recessed upward is formed in a lower surface of the portion of the first midsole portion <NUM> positioned in the midfoot support portion R2, and the second midsole portion <NUM> is disposed in the cutout 32a. The cutout 32a opens downward and toward the medial foot side. The side view shape of an upper surface <NUM> of the second midsole portion <NUM> is a curved shape protruding upward. The side view shape of the upper surface <NUM> of the second midsole portion <NUM> is a shape along the medial longitudinal arch of the foot or a shape approximating the medial longitudinal arch of the foot.

In <FIG>, the outer shape of the second midsole portion <NUM> is indicated by a broken line, the second midsole portion <NUM> is dot-hatched, and the outsole <NUM> is diagonal-hatched in order to facilitate understanding. As illustrated in <FIG>, the second midsole portion <NUM> is disposed only in a medial-foot-side region of the midfoot support portion R2 in the present embodiment. The second midsole portion <NUM> is only required to be disposed at least in a medial-foot-side region of the midfoot support portion R2. The second midsole portion <NUM> is only required to be disposed below at least a part or all of the medial longitudinal arch of the foot. The bottom surface of the second midsole portion <NUM> is a medial-foot-side region of the bottom surface of the midfoot support portion R2. The second midsole portion <NUM> is deformed by receiving the load when the shoe <NUM> comes contact with the ground to absorb an impact when the shoe <NUM> comes into contact with the ground. The bottom view shape of the second midsole portion <NUM> is a triangular shape in which the width in the front-rear direction narrows from the medial foot side toward the lateral foot side in the present embodiment.

The second midsole portion <NUM> includes a ground contact portion 33a that comes into contact with the ground. The ground contact portion 33a is formed on the bottom surface of the second midsole portion <NUM>. The ground contact portion 33a is the outsole <NUM> attached to the bottom surface of the second midsole portion <NUM> in the present embodiment. The ground contact portion 33a is positioned below the medial longitudinal arch of the foot. The position of the ground contact portion 33a in the front-rear direction is preferably within a region of <NUM>% to <NUM>% of the dimension of the sole <NUM> in the front-rear direction from the rear end of the sole <NUM>. The position of the ground contact portion 33a in the foot width direction is preferably positioned on the medial foot side relative to the shoe center axis C. As illustrated in <FIG>, the ground contact portion 33a has a portion positioned on a lowermost line Z along the front-rear direction connecting a lowermost point P1 of the forefoot support portion R1 and a lowermost point P2 of the rearfoot support portion R3 in a side view.

<FIG> is a cross-sectional view taken along line III-III in <FIG>. The medial-foot-side side surface of the second midsole portion <NUM> is the medial-foot-side side surface of the midfoot support portion R2. The medial-foot-side side surface of the second midsole portion <NUM> is formed with a protrusion 33b protruding toward the medial foot side. The protrusion 33b is formed over the entire length of the medial-foot-side side surface of the second midsole portion <NUM>. The protrusion 33b is preferably in a region ranging from <NUM>% to <NUM>% of the dimension of the sole <NUM> in the front-rear direction from the rear end of the sole <NUM>. The protrusion 33b includes a protruding end surface 33c facing the medial foot side. The protruding end surface 33c has a first protruding end surface 33d and a second protruding end surface 33e. The first protruding end surface 33d extends upward from the medial-foot-side edge of a bottom surface 31b of the midsole <NUM> (the bottom surface of the second midsole portion <NUM>) so as to be positioned toward the medial foot side. The second protruding end surface 33e is continuous with the first protruding end surface 33d and extends upward so as to be positioned toward the lateral foot side.

The boundary between the first protruding end surface 33d and the second protruding end surface 33e is a vertex 33f of the protrusion 33b positioned on the medialmost foot side. The vertex 33f is a point of the protruding end surface 33c where the inclination direction is switched. The vertex 33f extends in the front-rear direction. When a straight line connecting the medial-foot-side edge of an upper surface 31a of the midsole <NUM> (the upper surface of the first midsole portion <NUM>) and the medial-foot-side edge of the bottom surface 31b of the midsole <NUM> (the bottom surface of the second midsole portion <NUM>) is defined as a virtual straight line L, the vertex 33f of the protrusion 33b is preferably positioned on the medial foot side relative to the virtual straight line L and below the center of the virtual straight line L in the vertical direction. The upper surface <NUM> of the second midsole portion <NUM> is inclined downward from the medial foot side toward the lateral foot side. In other words, the cross-sectional shape of the upper surface <NUM> of the second midsole portion <NUM> along the foot width direction is an inclined shape inclined downward from the medial foot side toward the lateral foot side.

As illustrated in <FIG>, the outsole <NUM> is disposed below the midsole <NUM>. The outsole <NUM> is a hard member having a larger Young's modulus than the midsole <NUM>. The material of the outsole <NUM> is, for example, a material containing rubber as a main component and secondary components. Examples of the secondary components include a plasticizer, a reinforcing agent, and a crosslinking agent. As illustrated in <FIG>, the outsole <NUM> is partially disposed in the forefoot support portion R1, the midfoot support portion R2, and the rearfoot support portion R3. The outsole <NUM> is partially attached to the bottom surface 31b of the midsole <NUM>. In the present embodiment, a part of the outsole <NUM> disposed in the midfoot support portion R2 serves as the ground contact portion 33a. The outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are provided independently of each other. In other words, the outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are separated from each other.

<FIG> is a bottom view schematically illustrating a sole outline M and a fixed line N of the shoe <NUM> according to the first embodiment of the present invention. In <FIG>, scale lines G are indicated in order to facilitate understanding. The scale line G at the position corresponding to the rear end of the sole <NUM> is defined as <NUM>%, and the scale line G at the position corresponding to the front end of the sole <NUM> is defined as <NUM>%. The scale line G is provided for each <NUM>% of the dimension of the sole <NUM> in the front-rear direction. In a bottom view of the sole <NUM>, when a line connecting the outermost portion of the sole <NUM> is defined as a sole outline M, and a line connecting the portion where the sole <NUM> and the upper <NUM> positioned above the sole <NUM> are fixed is defined as a fixed line N, the sole outline M extends so as to surround the periphery of the fixed line N. When a distance in the foot width direction between a medial-foot-side portion M1 of the sole outline M and a medial-foot-side portion N1 of the fixed line N is D1, and a distance in the foot width direction between a lateral-foot-side portion M2 of the sole outline M and a lateral-foot-side portion N2 of the fixed line N is D2, the distance D1 and the distance D2 at the same position of the sole <NUM> in the front-rear direction satisfy a relationship of D1 > D2 in a region ranging from <NUM>% to <NUM>% of the dimension of the sole <NUM> in the front-rear direction from the rear end of the sole <NUM>. The distance D1 and the distance D2 more preferably satisfy the relationship D1 > D2 in a region ranging from <NUM>% to <NUM>% of the dimension of the sole <NUM> in the front-rear direction from the rear end of the sole <NUM>.

Next, effects of the sole <NUM> and the shoe <NUM> according to the present embodiment are described.

First, the inventors of the present invention conducted experiments focusing on the angle of falling of the foot, a body posture, and the like in a fatigued state after a person run a predetermined distance. Specifically, the inventors had the subjects run a distance of <NUM> or more, and observed and compared the inclination angle of the body, the state of the foot in contact with the ground, and the like at the initial stage of running when they were not fatigued and at the time when they were fatigued after running nearly <NUM>. From the experiments, the inventors found that as the fatigue level of the subjects increases, the midfoot of the foot tends to come into contact with the ground at the same time when the heel of the foot comes into contact with the ground, which causes the medial longitudinal arch to easily collapse and that the pressure on the midfoot of the foot to the forefoot becomes higher than the pressure on the heel of the foot when the inward falling of the foot is the largest between the ground contact and the foot off. Therefore, if it is possible to control the inward falling of the foot even in a fatigued state due to running, the effect of maintaining the stability of the foot of a runner at the time of ground contact during the running period is expected for a long time.

In the sole <NUM> according to the present embodiment, as illustrated in <FIG>, the ground contact portion 33a having a portion positioned on the lowermost line Z connecting the lowermost point P1 of the forefoot support portion R1 and the lowermost point P2 of the rearfoot support portion R3 in a side view is formed in the medial-foot-side region of the bottom surface of the midfoot support portion R2. Since the medial longitudinal arch of the foot is supported from below by the ground contact portion 33a, it is possible to control the collapse of the medial longitudinal arch of the foot. In the present embodiment, as illustrated in <FIG>, the medial-foot-side side surface of the midfoot support portion R2 is formed with the protrusion 33b protruding toward the medial foot side. Since the medial longitudinal arch of the foot is supported from the medial foot side by the protrusion 33b, it is possible to control the falling of the foot toward the medial foot side. That is, according to the present embodiment, it is possible to control the collapse of the medial longitudinal arch and the falling of the foot toward the medial foot side to stably support the midfoot of the sole of the wearer. To control the collapse of the medial longitudinal arch and the falling of the foot toward the medial foot side as in the present embodiment is particularly effective when a runner is increasingly fatigued. That is, it is possible to control overpronation under increased fatigue due to running.

In the present embodiment, as illustrated in <FIG>, the protrusion 33b is formed on the medial-foot-side side surface of the midsole <NUM>, and when a straight line connecting the medial-foot-side edge of the upper surface 31a of the midsole <NUM> and the medial-foot-side edge of the bottom surface 31b of the midsole <NUM> is defined as the virtual straight line L, the vertex 33f of the protrusion 33b is positioned on the medial foot side relative to the virtual straight line L and below the center of the virtual straight line L in the vertical direction. With this structure, it is possible to prevent the protrusion 33b from locally bending when the medial longitudinal arch of the foot is about to fall toward the medial foot side. That is, when the medial longitudinal arch of the foot is about to fall toward the medial foot side, the compressive deformation of the protrusion 33b can be promoted. Therefore, it is possible to further control the falling of the foot toward the medial foot side.

In the present embodiment, as illustrated in <FIG>, the protrusion 33b includes the protruding end surface 33c facing the medial foot side, and the protruding end surface 33c has the first protruding end surface 33d extending upward from the medial-foot-side edge of the bottom surface 31b of midsole <NUM> so as to be positioned toward the medial foot side, and the second protruding end surface 33e continuous with the first protruding end surface 33d and extending upward so as to be positioned toward the lateral foot side. With this structure, the vertex 33f positioned at the boundary between the first protruding end surface 33d and the second protruding end surface 33e is positioned at a position separated upward from the ground, and it is possible to prevent the protrusion 33b from locally bending when the medial longitudinal arch of the foot is about to fall toward the medial foot side. That is, when the medial longitudinal arch of the foot is about to fall toward the medial foot side, the compressive deformation of the protrusion 33b can be promoted. Therefore, it is possible to further control the falling of the foot toward the medial foot side.

According to the claimed invention, as illustrated in <FIG>, in the region ranging from <NUM>% to <NUM>% of the dimension of the sole <NUM> in the front-rear direction from the rear end of the sole <NUM>, the distance D1 in the foot width direction between the medial-foot-side portion M1 of the sole outline M and the medial-foot-side portion N1 of the fixed line N is longer than the distance D2 in the foot width direction between the lateral-foot-side portion M2 of the sole outline M and the lateral-foot-side portion N2 of the fixed line N. With this structure, the medial longitudinal arch of the foot is supported from the medial foot side by the sole <NUM>, and it is possible to control the falling of the foot toward the medial foot side.

In the present embodiment, as illustrated in <FIG>, the outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are provided independently of each other. With this structure, the load generated when the ground contact portion 33a comes into contact with the ground can be easily transmitted only to the second midsole portion <NUM> formed with the ground contact portion 33a, and it is possible to more reliably compress and deform the second midsole portion <NUM>. Therefore, it is possible to enhance the cushioning property of the second midsole portion <NUM> of the sole <NUM> positioned below the medial longitudinal arch of the foot. In other words, it is possible for the second midsole portion <NUM> of the sole <NUM> positioned below the medial longitudinal arch of the foot to easily absorb an impact when the ground contact portion 33a comes into contact with the ground.

In the present embodiment, as illustrated in <FIG>, the second midsole portion <NUM> positioned below the medial longitudinal arch where the wearer is likely to feel a thrust is formed separately from the first midsole portion <NUM>, and the hardness of the second midsole portion <NUM> is lower than the hardness of the first midsole portion <NUM>. With this structure, a thrust occurring when the shoe <NUM> comes into contact with the ground is less likely to be transmitted to the medial longitudinal arch of the foot, and it is possible to expect the effect of improving the comfort while the wearer runs.

In the present embodiment, as illustrated in <FIG>, the upper surface <NUM> of the second midsole portion <NUM> is inclined downward from the medial foot side toward the lateral foot side. With this structure, the wearer is less likely to feel a thrust to the medial longitudinal arch of the foot, and it is possible to expect the effect of improving the comfort while the wearer runs.

Note that, as illustrated in <FIG>, as long as the sole <NUM> includes the protrusion 33b protruding from the medial-foot-side side surface of the midfoot support portion R2 toward the medial foot side, the fall of the foot toward the medial foot side can be controlled. Therefore, the structure of the protrusion 33b is not limited to the illustrated example. For example, the vertex 33f of the protrusion 33b is preferably positioned below the center of the virtual straight line L in the vertical direction, but may be positioned at the same height as the center of the virtual straight line L in the vertical direction or above the center of the virtual straight line L in the vertical direction. For example, the shape of the protruding end surface 33c of the protrusion 33b is preferably the illustrated shape, but may be a linear shape along the vertical direction or may be a shape inclined from the upper side toward the lower side so as to be positioned toward the medial foot side.

In the above embodiment, as illustrated in <FIG>, the ground contact portion 33a disposed in the midfoot support portion R2 is the outsole <NUM>, but the ground contact portion 33a may be a part of the midsole <NUM>. For example, a part or all of the bottom surface of the second midsole portion <NUM> may be served as the ground contact portion 33a. When the ground contact portion 33a disposed in the midfoot support portion R2 is a part of the midsole <NUM>, the outsole <NUM> is only required to be disposed at least in the forefoot support portion R1 and the rearfoot support portion R3.

The bottom view shape of the second midsole portion <NUM> illustrated in <FIG>, the side view shape of the upper surface <NUM> of the second midsole portion <NUM> illustrated in <FIG>, and the cross-sectional shape of the upper surface <NUM> of the second midsole portion <NUM> along the foot width direction illustrated in <FIG> are not limited to the illustrated examples, and may be appropriately changed. For example, the cross-sectional shape of the upper surface <NUM> of the second midsole portion <NUM> along the foot width direction may be a flat shape along the foot width direction.

<FIG> is a perspective view of a shoe 1A according to a second embodiment of the present invention. A shoe 1A according to the second embodiment is different from the shoe <NUM> according to the first embodiment in the range of a second midsole portion <NUM>. In <FIG>, the range of the second midsole portion <NUM> is indicated by a broken line.

The second midsole portion <NUM> is disposed from a medial-foot-side region of a midfoot support portion R2 to a lateral-foot-side region of a rearfoot support portion R3. The second midsole portion <NUM> includes a first portion <NUM>, a second portion 33i, and a third portion 33j. The first portion <NUM> is disposed in the medial-foot-side region of the midfoot support portion R2. The third portion 33j extends obliquely rearward from the first portion <NUM> toward the lateral foot side. The third portion 33j is disposed over a part of a central region of the midfoot support portion R2 in the foot width direction and a part of a central region of the rearfoot support portion R3 in the foot width direction. The second portion 33i extends from the third portion 33j rearward and toward the lateral foot side. The second portion 33i is disposed over a part of a lateral-foot-side region of the midfoot support portion R2, the lateral-foot-side region of the rearfoot support portion R3, and a heel-side region of the rearfoot support portion R3. The second portion 33i reaches the rear end of the rearfoot support portion R3. The second midsole portion <NUM> is disposed avoiding a medial-foot-side region of the rearfoot support portion R3.

A ground contact portion 33a is disposed on the bottom surface of the first portion <NUM> and the bottom surface of the second portion 33i. The ground contact portion 33a is disposed in the medial-foot-side region of the midfoot support portion R2 of the bottom surface of the second midsole portion <NUM> and in the lateral-foot-side region and the heel-side region of the rearfoot support portion R3 of the bottom surface of the second midsole portion <NUM>. Note that the third portion 33j may be omitted. The second midsole portion <NUM> is only required to be disposed in the medial-foot-side region of the midfoot support portion R2 and the lateral-foot-side region of the rearfoot support portion R3. In the present embodiment, it is possible to achieve the same effects as those of the first embodiment described above.

In a heel-strike running method, the lateral-foot-side region of the rearfoot support portion R3 first comes into contact with the ground, and the lateral-foot-side region of the rearfoot support portion R3 toward the medial-foot-side region of the midfoot support portion R2 sequentially comes into contact with the ground. In the present embodiment, the second midsole portion <NUM> is disposed from the medial-foot-side region of the midfoot support portion R2 to the lateral-foot-side region of the rearfoot support portion R3. With this structure, it is possible to enhance the cushioning property of the medial-foot-side region of the midfoot support portion R2 as well as the cushioning property of the lateral-foot-side region of the rearfoot support portion R3. Therefore, it is possible to reduce the speed of the falling of the foot toward the medial foot side.

In the present embodiment, the second midsole portion <NUM> is disposed in the central region of the midfoot support portion R2 in the foot width direction and in the central region of the rearfoot support portion R3 in the foot width direction. With this structure, a wearer is less likely to feel a local thrust when the lateral-foot-side region of the rearfoot support portion R3 toward the medial-foot-side region of the midfoot support portion R2 sequentially comes into contact with the ground, and it is possible to expect the effect of improving the comfort while the wearer runs.

<FIG> is a cross-sectional view illustrating a shoe 1B according to a third embodiment of the present invention and corresponds to a cross-sectional view taken along line III-III in <FIG>. The shoe 1B according to the third embodiment is different from the shoe <NUM> according to the first embodiment in that a plate <NUM> is disposed between a first midsole portion <NUM> and a second midsole portion <NUM>.

The plate <NUM> is disposed between the first midsole portion <NUM> and the second midsole portion <NUM>. The plate <NUM> is disposed in a groove <NUM> formed in the bottom surface of the first midsole portion <NUM>. The groove <NUM> is only required to be formed in one of the first midsole portion <NUM> and the second midsole portion <NUM>. The hardness of the plate <NUM> is higher than the hardness of the first midsole portion <NUM> and the hardness of the second midsole portion <NUM>.

The material of the plate <NUM> is, for example, short carbon fiber reinforced material, fiber reinforced resin, non-fiber reinforced resin, or fiber fabric material. The fiber reinforced resin is, for example, carbon fiber, glass fiber, aramid fiber, Dyneema fiber, Zylon fiber, or boron fiber. The non-fiber reinforced resin is, for example, polymer resin. The polymer resin is, for example, thermoplastic polyurethane (TPU) or thermoplastic elastomer (TPA). The fiber fabric material is, for example, knitted fabric or woven fabric of polyester fiber, nylon fiber, or the like. In the present embodiment, it is possible to achieve the same effects as those of the first embodiment described above.

In the present embodiment, the plate <NUM> is disposed between the first midsole portion <NUM> and the second midsole portion <NUM>, and the hardness of the plate <NUM> is higher than the hardness of the first midsole portion <NUM> and the hardness of the second midsole portion <NUM>. With this structure, the load generated when a ground contact portion 33a comes into contact with the ground can be easily transmitted to a wide range of the second midsole portion <NUM>, and it is possible to compress and deform a wide range of the second midsole portion <NUM>. Therefore, it is possible for the second midsole portion <NUM> of a sole <NUM> positioned below the medial longitudinal arch of a foot to easily absorb an impact when the ground contact portion 33a comes into contact with the ground.

<FIG> is a bottom view of a shoe 1C according to a fourth embodiment of the present invention. <FIG> is a cross-sectional view taken along line VIII-VIII in <FIG>. The shoe 1C according to the fourth embodiment is different from those according to the first to third embodiments in that at least a part of an outsole <NUM> serving as a ground contact portion 33a and at least a part of the other outsole <NUM> are connected to each other and that a portion where the outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are connected to each other is disposed in a recess <NUM>. In the following description, the portion where the outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are connected to each other can also be referred to as a connecting portion <NUM>. Although the connecting portion <NUM> is also the outsole <NUM>, the connecting portion <NUM> is not hatched in <FIG> and <FIG> in order to clarify the range of the connecting portion <NUM>.

As illustrated in <FIG>, a bottom surface 31b of a midsole <NUM> is formed with the recess <NUM> recessed upward. The recess <NUM> is formed on the bottom surface of a first midsole portion <NUM> in the present embodiment. As illustrated in <FIG>, the recess <NUM> is disposed in a region in the periphery of the second midsole portion <NUM>, excluding a region along the medial-foot-side edge. As illustrated in <FIG>, the connecting portion <NUM> is disposed in the recess <NUM>. In <FIG>, a boundary between the outsole <NUM> serving as the ground contact portion 33a and the connecting portion <NUM>, and a boundary between the other outsole <NUM> and the connecting portion <NUM> are indicated by broken lines. At least a part of the outsole <NUM> serving as the ground contact portion 33a and at least a part of the other outsole <NUM> are only required to be connected to each other. In the present embodiment, it is possible to achieve the same effects as those of the first embodiment described above.

In the present embodiment, the portion where the outsole <NUM> serving as the ground contact portion 33a and the other outsole <NUM> are connected to each other is disposed in the recess <NUM>. With this structure, the load generated when the ground contact portion 33a comes into contact with the ground can be easily transmitted only to the second midsole portion <NUM> formed with the ground contact portion 33a, and it is possible to reliably compress and deform the second midsole portion <NUM>. Therefore, it is possible for the second midsole portion <NUM> of a sole <NUM> positioned below the medial longitudinal arch of a foot to easily absorb an impact when the ground contact portion 33a comes into contact with the ground.

Claim 1:
A sole (<NUM>) of a shoe (<NUM>) comprising: a forefoot support portion (R1) supporting a forefoot of a foot of a wearer; a midfoot support portion (R2) supporting a midfoot of the foot of the wearer; and a rearfoot support portion (R3) supporting a rearfoot of the foot of the wearer, the forefoot support portion, the midfoot support portion, and the rearfoot support portion being connected in order from a front side toward a rear side, wherein
a ground contact portion (33a) having a portion positioned on a lowermost line connecting a lowermost point of the forefoot support portion and a lowermost point of the rearfoot support portion in a side view is formed in a medial-foot-side region of a bottom surface of the midfoot support portion, and
a protrusion (33b) protruding toward a medial foot side is formed on a medial-foot-side side surface of the midfoot support portion,
wherein,
when a line connecting an outermost portion of the sole is defined as a sole outline and a line connecting a portion where the sole and an upper (<NUM>) positioned above the sole are fixed is defined as a fixed line in a bottom view of the sole, the sole outline extends so as to surround a periphery of the fixed line, characterized in that
in a region ranging from <NUM>% to <NUM>% of a dimension of the sole in a front-rear direction from a rear end of the sole, at the same position of the sole (<NUM>) in the front-rear direction a distance in a foot width direction between a medial-foot-side portion of the sole outline and a medial-foot-side portion of the fixed line is longer than a distance in the foot width direction between a lateral-foot-side portion of the sole outline and a lateral-foot-side portion of the fixed line.