SHOE STRUCTURE

Description

TECHNICAL FIELD

The present disclosure relates to a shoe structure.

BACKGROUND ART

Patent Literature 1 discloses a shoe that can improve a fit. This shoe has a sole for placing a foot and an upper portion for covering the foot, is provided with a loose portion in the sole, and thereby secures stretchability in a front-rear direction.

CITATION LIST

Patent Literature

• • Patent Literature 1: Japanese Patent Laid-Open No. 2015-002850

SUMMARY OF INVENTION

Technical Problem

This kind of shoe employs a structure in which a bottom surface on a toe tip side of the sole is curved upward toward the front and which is referred to as a toe spring. A wearer of such a shoe lands from the heel, inclines the foot to roll the foot forward, and thereby walks while moving their center of gravity forward. Thus, there has been a problem that a wearer of a shoe in the related art has difficulty in performing an action of gripping the toes in walking. In this case, muscles of the lower legs and feet are less likely to be sufficiently used, which could lead to a decrease in physical function.

Accordingly, the present invention provides a shoe structure in which toes can easily grip in a worn state.

Solution to Problem

A shoe structure of the present invention includes an outsole, in the outsole, a first lower surface on a back side of a portion on which a heel of a foot is placed and a second lower surface on a back side of a portion on which a ball of the foot and a ball of the little toe of the foot are placed are formed to be flush, and a third lower surface on a back side of a portion on which toe tips of the foot are placed is formed to be flat and is provided with a step portion such that the third lower surface is positioned above the second lower surface.

Advantageous Effects of Invention

In the present invention, because a step portion is provided between a third lower surface and a second lower surface and the third lower surface has a flat shape, the third lower surface on which toe tips are placed easily bends downward. Thus, a wearer is enabled to easily perform an action of gripping the toes in the toe tips.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an exploded perspective view schematically illustrating a shoe according to an embodiment.

FIG. 2 is a bottom view of a skeleton structure of a foot.

FIG. 3 is a bottom view of an outsole according to the embodiment.

FIG. 4 is a cross-sectional view along IV-IV in FIG. 3.

FIG. 5 is a plan view of the outsole.

FIG. 6 is a side view of the outsole.

FIG. 7 is an enlarged view of FIG. 4.

FIG. 8 is a plan view of an outsole according to another embodiment.

FIG. 9 is a side view of the outsole according to the other embodiment.

FIG. 10 is a side view of an outsole according to a second other embodiment.

DESCRIPTION OF EMBODIMENTS

1. Configuration

Embodiments of the present invention will hereinafter be described with reference to the drawings.

FIG. 1 is an exploded perspective view schematically illustrating a shoe 1 according to the present embodiment. Although a description will proceed with reference to drawings of the shoe 1 for a right foot in the following, a similar description can apply to a shoe for a left foot. Further, FR, UP, and IN in the drawings respectively indicate front of the foot, an upper area of the foot, and a width-direction inner side of the foot.

The width-direction inner side of the foot represents a left direction in the right foot and a right direction in the left foot. Further, a width-direction outer side of the foot represents the right direction in the right foot and the left direction in the left foot.

The shoe 1 is a foot wear which protects toe tips to portions around an ankle of the foot of a wearer. The shoe 1 of the present embodiment is specifically a shoe for golf.

The shoe 1 has an upper portion 3, an inner sole 5, a midsole 7, and an outsole 70. In the shoe 1, the upper portion 3 covers the foot of the wearer in a horizontal direction and from an upper area. The inner sole 5 is a portion on which the foot of the wearer is directly placed, absorbs an impact on the foot, and improves a fit of the shoe 1 for the foot. The midsole 7 is a portion which is provided between the inner sole 5 and the outsole 70 and absorbs mainly an impact on the foot. The outsole 70 is a portion, in the shoe 1, which contacts with a ground surface, and is arranged below the midsole 7. The outsole 70 protects the foot of the wearer from an impact to be received from the ground surface and unevenness of the ground surface. Thus, in general, it is desirable that the outsole 70 have a sufficient thickness.

FIG. 2 is a bottom view illustrating a skeleton structure 10 of the foot. FIG. 2 illustrates the skeleton structure 10 of the foot as seen from a lower area, and a part of bones is covered because bones overlap each other. In a plan view as seen from a face side of the foot, a manner in which the bones overlap each other is different from that in the bottom view in FIG. 2.

As illustrated in FIG. 2, the skeleton structure 10 of the foot is configured with a calcaneus bone 12, a talus bone 14, a navicular bone 16, a cuboideum bone 18, first to third cuneiform bones 20, 22, and 24, first to fifth metatarsal bones 26, 28, 30, 32, and 34, first to fifth proximal phalanges 36, 38, 40, 42, and 44, second to fifth middle phalanges 46, 48, 50, and 52, and first to fifth distal phalanges 54, 56, 58, 60, and 62. Front end portions of the first to fifth metatarsal bones 26, 28, 30, 32, and 34 are first to fifth metatarsal heads 26A (also referred to as a ball of the foot 26A), 28A, 30A, 32A, and 34A (also referred to as a ball of the little toe 34A). A step-shaped portion positioned in a front portion of the calcaneus bone 12 is an anterior part of the calcaneus bone (also referred to as a calcaneal tubercle) 12A.

A skeleton of a big toe (also referred to as a first toe) has the first proximal phalanges 36 and the first distal phalange 54. The big toe mainly bends at a first joint (also referred to as an interphalangeal joint) 54B, which connects the first proximal phalange 36 and the first distal phalange 54, and at a second joint (also referred to as a metatarso-phalangeal joint) 36B, which connects the first proximal phalange 36 and the first metatarsal bone 26. That is, the big toe has two bones and two joints and bends at two joints.

Meanwhile, skeletons of the index toe, middle toe, fore toe, and small toe (also referred to as second toe, third toe, fourth toe, and fifth toe, respectively) have the second to fifth proximal phalanges 38, 40, 42, and 44, the second to fifth middle phalanges 46, 48, 50, and 52, and the second to fifth distal phalanges 56, 58, 60, and 62. The second to fifth distal phalanges 56, 58, 60, and 62 and the second to fifth middle phalanges 46, 48, 50, and 52 are connected together via first joints (also referred to as distal interphalangeal joints) 56B, 58B, 60B, and 62B. The second to fifth middle phalanges 46, 48, 50, and 52 and the second to fifth proximal phalanges 38, 40, 42, and 44 are connected together via second joints (also referred to as proximal interphalangeal joints) 46B, 48B, 50B, and 52B. The second to fifth proximal phalanges 38, 40, 42, and 44 and the second to fifth metatarsal heads 28A, 30A, 32A, and 34A are connected together via third joints (also referred to as metatarso-phalangeal joints) 38B, 40B, 42B, and 44B. That is, each of the index toe to the small toe has three bones and three joints and bends at three joints.

FIG. 3 is a bottom view of the outsole 70. FIG. 4 is a cross-sectional view of the outsole 70 in a IV-IV cross section. FIG. 3 illustrates a rough positional relationship of the skeleton structure 10 of the foot which corresponds to the outsole 70 while overlapping those with imaginary lines.

As illustrated in FIG. 3 and FIG. 4, in a lower surface 70A as a surface, of the outsole 70, which contacts with the ground surface, a first lower surface 71, a force pad (second lower surface) 73, and a third lower surface 75 are formed.

In the outsole 70, the first lower surface 71 is a back side of a first support portion 72 as a portion on which a heel of the foot is placed, that is, a lower surface 70A side of the first support portion 72. More specifically, the first support portion 72 is a portion that the calcaneus bone 12 substantially overlaps in a planar view in a case where the wearer wears the shoe 1. The first lower surface 71 has a circular spike 71a and a plurality of spikes 71b and 71c which are formed around the spike 71a.

In the first lower surface 71, the spike 71a is a portion which supports a load to be received from the heel of the foot and prevents slip between the outsole 70 and the ground surface by digging into the ground surface. The spike 71a has an annular protruding line which defines an outer shape of the spike 71a and protrudes downward and a circular protrusion which is positioned at a center of the annular protruding line and protrudes downward. In the annular protruding line, circular protrusions protruding downward are aligned at regular intervals. From each of side surfaces of the aligned protrusions, a rib extends which is inclined in a direction in which a thickness in a height direction on the center side of the annular protruding line becomes smaller toward the center of the annular protruding line.

In the first lower surface 71, the spikes 71b and 71c are portions which dig into the ground surface and thereby prevent slip between the outsole 70 and the ground surface. The spike 71b is a trapezoidal protrusion which is annularly aligned around the spike 71a and is inclined in a direction in which the thickness in the height direction becomes larger toward a center of the spike 71a. The spike 71c is a protrusion, which has a generally triangular prism shape and is arranged between the spikes 71b, and protrudes downward.

In the outsole 70, the force pad 73 is a back side of a second support portion 74 as a portion on which the ball of the foot 26A and the ball of the little toe 34A are placed, that is, the lower surface 70A side of the second support portion 74. The force pad 73 has spikes 73a and 73b and a plurality of spikes 73c.

In the force pad 73, the spikes 73a and 73b are portions which respectively support loads to be received from the ball of the foot 26A and the ball of the little toe 34A of the foot and prevent slip by digging into the ground surface. Each of the spikes 73a and 73b has a similar shape to that of the spike 71a and has a different size depending on a magnitude of the load to be received. That is, the spike 71a which supports the largest load from the heel is formed to be largest among the spikes 71a, 73a, and 73b. Further, the spike 73a which supports the load from the ball of the foot 26A is formed to be second largest among the spikes 71a, 73a, and 73b. In addition, the spike 73b which supports the smallest load from the ball of the little toe 34A is formed to be smallest among the spikes 71a, 73a, and 73b.

In the force pad 73, the spikes 73c are portions which dig into the ground surface and thereby prevent slipping. The spikes 73c are protrusions, each of which has a triangular prism shape and is circularly arranged around each of the spikes 73a and 73b, and protrudes downward.

In the outsole 70, the third lower surface 75 is a back side of a third support portion 76 as a portion on which the toes of the foot are placed, that is, the lower surface 70A side of the third support portion 76. Specifically, in a case where the wearer wears the shoe 1, in the planar view, the first to fifth proximal phalanges 36, 38, 40, 42, and 44, the second to fifth middle phalanges 46, 48, 50, and 52, and the first to fifth distal phalanges 54, 56, 58, 60, and 62 substantially overlap the third support portion 76. The third lower surface 75 has a ball of the foot support portion 75a and a ball of the little toe support portion 75b.

The ball of the foot support portion 75a is a portion which mainly overlaps the big toe of the foot of the wearer in the planar view. A large number of spikes 75c are formed in the ball of the foot support portion 75a. One spike 75c is formed with two elliptical protrusions protruding downward, which are coupled together. Each of the spikes 75c formed in the ball of the foot support portion 75a is arranged such that its front side is inclined in a direction in which the front side is positioned on the width-direction outer side of the foot.

The ball of the little toe support portion 75b is a portion which substantially overlaps the index toe to the small toe of the foot of the wearer in the planar view. A large number of spikes 75d are formed in the ball of the little toe support portion 75b. One spike 75d is formed with two elliptical protrusions protruding downward, which are coupled together. Each of the spikes 75d formed in the ball of the little toe support portion 75b is arranged such that its front side is inclined in a direction in which the front side is positioned on the width-direction inner side of the foot.

Between the ball of the foot support portion 75a and the ball of the little toe support portion 75b, a groove 75e is formed in which the lower surface 70A of the outsole 70 is concaved upward. Accordingly, the ball of the foot support portion 75a and the ball of the little toe support portion 75b are enabled to easily move independently from each other.

As illustrated in FIG. 4, in the first lower surface 71, a lower end of the spike 71a and lower ends of the spikes 71b and 71c are respectively formed to be generally flush in the height direction. Thus, the first lower surface 71 can be considered to be a flat surface which is formed at the same height as the lower end of the spike 71a and the lower ends of the spikes 71b and 71c.

Similarly, in the force pad 73, lower ends of the spikes 73a and 73b and lower ends of the spikes 73c are respectively formed to be generally flush in the height direction. Thus, the force pad 73 can be considered to be a flat surface which is formed at the same height as the lower ends of the spikes 73a and 73b and the lower ends of the spikes 73c.

Further, in the third lower surface 75, lower ends of the spikes 75c and 75d are respectively formed to be generally flush in the height direction. Thus, the third lower surface 75 can be considered to be a flat surface which is formed at the same height as the lower ends of the spikes 75c and 75d.

As illustrated in FIG. 3 and FIG. 4, in the lower surface 70A of the outsole 70, between the force pad 73 and the third lower surface 75, a step portion 77 is formed which extends in a width direction of the foot. The step portion 77 has a recess portion 77a and steps 77b and 77c. The recess portion 77a is a portion in which the lower surface 70A is recessed upward. The step 77b is a step which connects the recess portion 77a and the force pad 73 together. The step 77c is a step which connects the recess portion 77a and the third lower surface 75 together. A difference in a height between the recess portion 77a and the force pad 73, which is produced by the step 77b, is larger, only by a difference d, than a difference in the height between the recess portion 77a and the third lower surface 75, which is produced by the step 77c. That is, by formation of the step portion 77, the third lower surface 75 is arranged above the force pad 73 only by the difference d.

Further, the first lower surface 71 is generally flush with the force pad 73. Thus, when the wearer wears the shoe 1 and stands upright on a flat ground surface, portions, which contact with the ground surface, in the lower surface 70A of the outsole 70 are the first lower surface 71 and the force pad 73, and the third lower surface 75 is spaced apart from the ground surface only by the difference d. In such a manner, a room for a downward curve is likely to be provided below the third lower surface 75, on which the toes of the foot are placed, in the shoe 1.

In the present embodiment, a face side of the outsole 70, that is, an upper surface 70B of the outsole 70 is mildly inclined in a direction in which a rear side becomes higher than a front side. Thus, a first upper surface 72B as a face side of the first support portion 72 is positioned above a second upper surface 74B as a face side of the second support portion 74 and a third upper surface 76B as a face side of the third support portion 76. In such a manner, because with a configuration in which the first upper surface 72B is arranged at a high position in the upper surface 70B, the calcaneus bone 12 of the wearer is maintained at a high position, and a pelvis is thereby enabled to be easily inclined forward, for example, the above configuration is considered to be suitable for a case where a swing or the like of golf is performed. Further, in the upper surface 70B, a front portion of the second upper surface 74B and the third upper surface 76B are formed to be flat.

FIG. 5 is a plan view of the outsole 70 and illustrates a configuration of the upper surface 70B. In the outsole 70, in the third upper surface 76B on which the toes of the foot are placed, in order to expand movable ranges of the big toe and the index toe to the small toe, two first lateral grooves 81 and 82 and three second lateral grooves 83, 84, and 85 as lateral grooves extending in the width direction are formed.

Each of the first lateral grooves 81 and 82 is formed in the big toe placing portion 80A as a portion, on which the big toe is placed, in the third upper surface 76B, and is a groove which is concaved downward. Each of the first lateral grooves 81 and 82 extends in the width direction and is gently curved in a direction in which a front side projects. In the planar view, the first lateral groove 81 is provided in a position which goes along the first joint 54B of the big toe of the foot when the wearer wears the shoe 1. In the planar view, the first lateral groove 82 is provided in a position which goes along the second joint 36B of the big toe of the foot when the wearer wears the shoe 1. In such a manner, the big toe placing portion 80A is provided with the two first lateral grooves 81 and 82 which are aligned in a front-rear direction of the foot, corresponding to the number of joints of the big toe.

The first lateral grooves 81 and 82 are formed to be aligned in order in which widths in the front-rear direction stepwise become wider toward a front side of the foot (a tip end side of the toes). That is, a width W1, in the front-rear direction, of the first lateral groove 81 which is arranged on the front side of the foot relative to the first lateral groove 82 is wider than a width W2 of the first lateral groove 82 in the front-rear direction. Specifically, in the present embodiment, the width W1 is set to 3.0 mm, and the width W2 is set to 2.0 mm.

Each of the second lateral grooves 83 to 85 is formed in an other-toe placing portion 80B as a portion, on which the index toe to the small toe are placed, in the third upper surface 76B, and is a groove which is concaved downward. Each of the second lateral grooves 83 to 85 extends in the width direction and is gently curved in a direction in which a front side projects along arrangement of each of the joints. In the planar view, the second lateral groove 83 is provided in a position which goes along the first joints 56B, 58B, 60B, and 62B of the index toe to the small toe of the foot when the wearer wears the shoe 1. In the planar view, the second lateral groove 84 is provided in a position which goes along the second joints 46B, 48B, 50B, and 52B of the index toe to the small toe of the foot when the wearer wears the shoe 1. In the planar view, the second lateral groove 85 is provided in a position which goes along the third joints 38B, 40B, 42B, and 44B of the foot when the wearer wears the shoe 1. In such a manner, the other-toe placing portion 80B is provided with the three second lateral grooves 83 to 85 which are aligned in the front-rear direction of the foot, corresponding to the number of joints of each of the index toe to the small toe. Further, on extended lines of the second lateral grooves 84 and 85, the first lateral grooves 81 and 82 are positioned.

Similarly to the first lateral grooves 81 and 82, the second lateral grooves 83 to 85 are formed to be aligned in order in which widths in the front-rear direction stepwise become wider toward the front side of the foot. That is, a width W3 of the second lateral groove 83 in the front-rear direction is wider than a width W4 of the second lateral groove 84 in the front-rear direction. Further, the width W4 is wider than a width W5 of the second lateral groove 85 in the front-rear direction. Specifically, in the present embodiment, the width W3 is set to 2.0 mm, the width W4 is set to 1.5 mm, and the width W5 is set to 1.0 mm. Further, the widths W1 and W2 of the first lateral grooves 81 and 82 are set to breadths equal to or larger than the widths W3 to W5 of the second lateral grooves 83 to 85. In particular, the width W1 of the first lateral groove 81 which is positioned on the extended line of the second lateral groove 84 is wider than the width W4 of the second lateral groove 84. Further, the width W2 of the first lateral groove 82 which is positioned on the extended line of the second lateral groove 85 is wider than the width W5 of the second lateral groove 85.

FIG. 6 is a side view of the outsole 70 and illustrates the outsole 70 as seen from the front side of the foot. As illustrated in FIG. 6, lengths L1 and L2 of the first lateral grooves 81 and 82 which correspond to the big toe are shorter than lengths L3 to L5 of the second lateral grooves 83 to 85 which correspond to the index toe to the small toe.

Further, as illustrated in FIG. 6, the first lateral grooves 81 and 82 are formed to be aligned in order in which depths in an up-down direction stepwise become deeper toward the front side of the foot. That is, a depth D1 of the first lateral groove 81 on the front side of the foot relative to the first lateral groove 82 is larger than a depth D2 of the first lateral groove 82. Specifically, in the present embodiment, the depth D1 is set to 4.0 mm, and the depth D2 is set to 3.0 mm.

Similarly, the second lateral grooves 83 to 85 are formed to be aligned in order in which depths in the up-down direction stepwise become deeper toward the front side of the foot. That is, a depth D3 of the second lateral groove 83 which is closest to the front side of the foot among the second lateral grooves 83 to 85 is larger than depths D4 and D5 of the second lateral grooves 84 and 85. Further, the depth D4 of the second lateral groove 84 which is positioned on the front side of the foot relative to the second lateral groove 85 is larger than the depth D5 of the second lateral groove 85. Specifically, in the present embodiment, the depth D3 is set to 3.0 mm, the depth D4 is set to 2.0 mm, and the depth D5 is set to 1.0 mm. Further, the depths D1 and D2 of the first lateral grooves 81 and 82 are set to sizes equal to or larger than the depths D3 to D5 of the second lateral grooves 83 to 85. More specifically, the first lateral grooves 81 and 82 are respectively present on extended lines of the second lateral grooves 84 and 85, but the depths D1 and D2 of the first lateral grooves 81 and 82 which are positioned on the width-direction inner side of the foot are larger than the depths D4 and D5 of the second lateral grooves 84 and 85.

The first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are formed, and thicknesses of the third support portion 76 locally become small. Thus, in the third support portion 76, bending rigidity, in the up-down direction, of portions in which the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are formed is locally lowered.

Respective lowering amounts of the local bending rigidity of the third support portion 76 due to the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 become larger as the widths W1 to W5 in the front-rear direction become wider. Similarly, respective lowering amounts of the local bending rigidity of the third support portion 76 due to the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 become larger as the depths D1 to D5 become deeper. Thus, in the third support portion 76, the portion in which the first lateral groove 81 positioned on the front side is formed has smaller bending rigidity in the up-down direction than the portion in which the first lateral groove 82 positioned on the rear side is formed. Similarly, in the third support portion 76, the portion in which the second lateral groove 83 positioned on the front side relative to the second lateral groove 84 is formed has smaller bending rigidity in the up-down direction than the portion in which the second lateral groove 84 is formed. Further, in the third support portion 76, the portion in which the second lateral groove 84 positioned on the front side relative to the second lateral groove 85 is formed has smaller bending rigidity in the up-down direction than the portion in which the second lateral groove 85 is formed.

Further, the depths D1 and D2 of the first lateral grooves 81 and 82 are larger than the depths D4 and D5 of the second lateral grooves 84 and 85. Thus, in the third support portion 76, the portions in which the first lateral grooves 81 and 82 are formed are likely to have smaller bending rigidity than the portions in which the second lateral grooves 83 to 85 are formed. Accordingly, when the wearer bends the big toe, force of the big toe is less likely to be released to the width-direction outer side, and the portions, in which the first lateral grooves 81 and 82 are formed, in the third support portion 76 are enabled to be easily curved.

2. Action and Working

FIG. 7 is an enlarged view of FIG. 4. FIG. 7 illustrates, by imaginary lines, a rough position of each portion of the index toe of the wearer wearing the shoe 1.

As described above, in the lower surface 70A of the outsole 70, by formation of the step portion 77, the third lower surface 75 is arranged above the force pad 73 only by the difference d. Further, the force pad 73 contacts with a ground when the wearer wearing the shoe 1 stands upright. Thus, as illustrated in FIG. 7, between the third lower surface 75 and a ground surface G, a gap is produced which has a height of a size equal to the difference d. In such a manner, because the gap is produced between the third lower surface 75 and the ground surface G, the wearer bends the big toe to the small toe of the foot and can thereby curve the third support portion 76 downward. In addition, because the third lower surface 75 is formed to be flat, the wearer easily curves the third support portion 76 downward.

When the wearer bends the big toe to the small toe of the foot, parts, which correspond to the first to fifth distal phalanges 54 to 62 as bones in farthest positions on the tip end side in the big toe to the small toe, are pressed mainly onto the third upper surface 76B. Further, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are formed along the joints of the big toe to the small toe of the foot. Thus, parts, in which the big toe to the small toe of the foot are pressed mainly onto the third upper surface 76B, are on the front side relative to the lateral grooves 81 and 82 and the second lateral grooves 83 to 85 in the third upper surface 76B. Specifically, in a case of the index toe illustrated as an example in FIG. 7, a second toe pad 56C corresponding to the second distal phalange 56 is pressed onto a load region P on the front side relative to the second lateral groove 83 in the third upper surface 76B. Accordingly, the load region P of the third upper surface 76B receives downward force, and the third support portion 76 curves downward.

As described above, in the third support portion 76, in the portions in which the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are formed, bending rigidity is locally lowered. Thus, when the wearer bends the big toe to the small toe and the third upper surface 76B thereby receives downward force, the third support portion 76 is likely to curve at the first lateral grooves 81 and 82 and the second lateral groove 83 to 85, which serve as starting points.

Further, as described above, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are respectively formed in positions along the joints of the big toe to the small toe. Thus, the third support portion 76 curves at the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 as the starting points, and the third upper surface 76B is thereby enabled to easily move along bend of the big toe to the small toe.

Further, as described above, the parts, in which the big toe to the small toe are pressed mainly onto the third upper surface 76B, are on the front side relative to the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 in the third upper surface 76B. Thus, bending moments to be exerted on the third support portion 76 become smaller in the portions, in which the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 which are positioned on the front side are formed, in the third support portion 76. On the other hand, the lowering amounts of the local bending rigidity of the third support portion 76 due to the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 become larger in the portions, in which the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 which are positioned on the front side are formed, in the third support portion 76. Thus, in the outsole 70, the first lateral groove 81 and the second lateral groove 83 on the front side, on which large bending moments are less likely to be exerted, are enabled to be easily largely bent. Further, the first joints 54B, 56B, 58B, 60B, and 62B of the big toe to the small toe largely bend when an action of gripping the toes is performed. Thus, in the third support portion 76, portions, in which the first lateral groove 81 and the second lateral groove 83 along the first joints 54B, 56B, 58B, 60B, and 62B are formed, are enabled to be easily bent, and the third upper surface 76B is thereby enabled to be easily bent along bend of the big toe to the small toe.

3. Effects and so Forth

As described in the foregoing, the shoe 1 of the present embodiment includes the outsole 70, in the outsole 70, the first lower surface 71 on the back side of the first support portion 72 as the portion on which the heel of the foot is placed and the force pad 73 on the back side of the second support portion 74 as the portion on which the ball of the foot 26A and the ball of the little toe 34A of the foot are placed are formed to be flush, and the third lower surface 75 on the back side of the third support portion 76 as the portion on which the toe tips of the foot are placed is formed to be flat and is provided with the step portion 77 such that the third lower surface 75 is positioned above the force pad 73.

Consequently, by the step portion 77, the gap is likely to be produced between the third lower surface 75 formed to be flat and the ground surface, and the third lower surface 75 on which the toe tips are placed are likely to bend downward. Thus, the wearer is enabled to easily perform an action of gripping the toes in the toe tips.

In the shoe 1 of the present embodiment, in the outsole 70, in the third upper surface 76B as the face side of the third support portion 76 as the portion on which the toe tips of the foot are placed, pluralities of the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 which extend in a width direction of the third support portion 76 are formed along the joints of the big toe and the other toes in order to expand the movable range of the big toe and the other toes.

Consequently, by the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85, the third lower surface 75 is enabled to easily bend. Thus, the wearer is enabled to easily perform the action of gripping the toes in the toe tips. Further, by the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85, a portion formed to be thin in the outsole 70 is minimized, and the action of gripping the toes is enabled to be easily performed. Thus, while the foot of the wearer is sufficiently protected, the action of gripping the toes is enabled to be easily performed.

In the shoe 1 of the present embodiment, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 include the plurality of first lateral grooves 81 and 82, which are formed in the big toe placing portion 80A as the portion on which the big toe is placed, and the plurality of second lateral grooves 83 to 85, which are formed in the other-toe placing portion 80B as the portion on which the other toes are placed.

Consequently, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are individually formed, and the wearer is thereby enabled to easily move the big toe and the other toes independently from each other. Thus, the wearer is enabled to easily perform the action of gripping the toes in the toe tips.

In the shoe 1 of the present embodiment, the number of first lateral grooves 81 and 82 is two, corresponding to the number of joints of the big toe, and the number of second lateral grooves 83 to 85 is three, corresponding to the number of joints of each of the other toes.

Consequently, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are enabled to respectively easily bend according to the joints of the big toe and the other toes. Thus, the wearer is enabled to easily perform the action of gripping the toes in the toe tips.

In the shoe 1 of the present embodiment, the pluralities of first lateral grooves 81 and 82 and second lateral grooves 83 to 85 are formed such that the respective widths W1 to W5 of the grooves stepwise become wider toward the tip end side of the toe tips.

Consequently, the outsole 70 is enabled to largely bend at the first lateral groove 81 and the second lateral groove 83 on the tip end side, on which moments are less likely to be exerted. Thus, the wearer is enabled to easily perform the action of gripping the toes.

In the shoe 1 of the present embodiment, the pluralities of first lateral grooves 81 and 82 and second lateral grooves 83 to 85 curve along the joints of the big toe and the other toes.

Consequently, the first lateral grooves 81 and 82 and the second lateral grooves 83 to 85 are enabled to be easily present along positions of the joints of the toes. Thus, the wearer is enabled to easily perform the action of gripping the toes in the toe tips.

4. Other Embodiments

The above-described embodiment only represents one form of the present invention, and optional modifications and practical applications are possible without departing from the scope of the gist of the present invention. In the following, other embodiments will be described as examples.

In the above-described embodiment, the shoe 1 has the first lateral grooves 81 and 82 which are formed in the big toe placing portion 80A and the second lateral grooves 83 to 85 which are formed, separately from the first lateral grooves 81 and 82, in the other-toe placing portion 80B; however, this is one example.

FIG. 8 is a plan view of an outsole 70 according to another embodiment.

As illustrated in FIG. 8, in the third upper surface 76B, the outsole 70 may have lateral grooves 181 to 183 which are formed across the big toe placing portion 80A and the other-toe placing portion 80B. Further, as illustrated in FIG. 8, the lateral grooves 181 to 183 may not be curved but may have linear shapes. The lateral grooves 181 to 183 are formed such that respective widths W11 to W13, in the front-rear direction, of the lateral grooves 181 to 183 stepwise become wider toward the tip end side of the toe tips.

FIG. 9 is a side view of the outsole 70 according to the other embodiment, which is illustrated in FIG. 8, as seen from front. As illustrated in FIG. 9, the lateral grooves 181 to 183 are formed to be inclined in a direction in which depths D11b to D13b on the width-direction inner side in the toe tips become shallower than depths D11a to D13a of the lateral grooves 181 to 183 on the width-direction outer side in the toe tips. Accordingly, in a case where the wearer bends the big toe, force is less likely to be released to the width-direction outer side of the foot, and the big toe is enabled to be easily bent.

That is, in the outsole 70 of the other embodiment, the plurality of lateral grooves 181 to 183 are formed such that the respective depths of the grooves become deeper toward the width-direction inner side of the toe tips.

Accordingly, the wearer is enabled to more easily bend the big toe. Thus, by bending the big toe, larger muscles than muscles which move in association with the other toes are enabled to be easily moved in association with the big toe.

In FIG. 8 and FIG. 9, a case is described where three lateral grooves 181 to 183 having linear shapes are provided; however, this is one example. It is sufficient that two or more lateral grooves are provided, and the lateral grooves may be curved along the respective joints of the toes.

In the above-described embodiment, a description is made on the assumption that the shoe 1 is a shoe for golf, but this is one example, and it is sufficient that the shoe 1 is a foot wear. For example, the shoe 1 may be a foot wear such as a sneaker which is suitable for a paved road surface.

FIG. 10 is a side view of an outsole 270 according to a second other embodiment. The outsole 270 is used as a shoe sole of a sneaker. As illustrated in FIG. 10, the outsole 270 of the second other embodiment does not have spikes or a force pad in a lower surface 270A. Further, as illustrated in FIG. 10, an upper surface 270B of the outsole 270 for the sneaker is flat compared to the upper surface 70B of the outsole 70 of the above-described embodiments, which is used for the shoe for golf, and an inclination which rises rearward is low. That is, a first upper surface 272B as a face side of a first support portion 272 on which the heel of the foot is placed is substantially flat compared to a second upper surface 274B as a face side of a second support portion 274 on which the ball of the foot and the ball of the little toe of the foot are placed and to a third upper surface 276B as a face side of a third support portion 276 on which the toe tips of the foot are placed.

Similarly to the above-described embodiments, the outsole 270 of the second other embodiment, which is applied to the sneaker, also has a first lower surface 271, a second lower surface 273, and a third lower surface 275. In the outsole 270, the third lower surface 275 as a back side of the third support portion 276 is formed to be flat so as to be positioned above, by a step portion 277, the second lower surface 273 as a back side of the second support portion 274. Further, the outsole 270 of the second other embodiment, which is applied to the sneaker, may also be configured to have a plurality of lateral grooves as illustrated in FIG. 5 or FIG. 8.

Further, it is possible to make a new embodiment by combining elements of the embodiment, the other embodiment, and the second other embodiment, which are described in the foregoing.

Industrial Applicability

The present invention is applicable to a shoe structure which includes an outsole. Specifically, the present invention is also applicable to a shoe of daily use such as a sneaker in addition to a shoe used for a specific purpose of use such as specific sport like a shoe for golf.

Reference Signs List

• • 1 shoe
  • 3 upper portion
  • 5 inner sole
  • 7 midsole
  • 70 outsole
  • 71 first lower surface
  • 72 first support portion (portion on which heel of foot is placed)
  • 73 force pad (second lower surface)
  • 74 second support portion (portion on which ball of the foot and ball of the little toe of foot are placed)
  • 75 third lower surface
  • 76 third support portion (portion on which toe tips of foot are placed)
  • 76B third upper surface (face side of portion on which toe tips of foot are placed)
  • 77 step portion
  • 81 first lateral groove (lateral groove)
  • 82 first lateral groove (lateral groove)
  • 83 second lateral groove (lateral groove)
  • 84 second lateral groove (lateral groove)
  • 85 second lateral groove (lateral groove)
  • 181 lateral groove
  • 183 lateral groove
  • 270 outsole
  • 271 first lower surface
  • 272 first support portion (portion on which heel of foot is placed)
  • 273 second lower surface
  • 274 second support portion (portion on which ball of the foot and ball of the little toe of foot are placed)
  • 275 third lower surface
  • 276 third support portion (portion on which toe tips of foot are placed)
  • 276B third upper surface (face side of portion on which toe tips of foot are placed)
  • 277 step portion