Insole and footwear

Abstract

Provided is an inner sole for an article of footwear, which enables a user to stand with stable posture and walk with stable posture. An inner sole (15) includes a pad (60), and is to be provided in a portion of the article of footwear, into which a foot is to be inserted. In plan view of the pad (60), the pad (60) is divided by a center line passing through a center (C1) of the pad (60) in a widthwise direction into an inner region (D1) and an outer region (D2). In plan view of the pad (60), the inner region (D1) is a region on which a first toe of the foot is to be positioned. In plan view of the pad (60), the outer region (D2) is a region on which a fifth toe of the foot is to be positioned. The pad (60) has a hole (40) that allows a load received by a ground-contact portion of the article of footwear from a heel of the foot at a position corresponding to the outer region (D2), to exceed a load received by the ground-contact portion of the article of footwear from the heel of the foot at a position corresponding to the inner region (D1).

Description

TECHNICAL FIELD

[0001] The present disclosure relates to an inner sole to be provided in an article of footwear to be worn on a human foot, and an article of footwear.BACKGROUND ART

[0002] In Patent Literature 1, there is described an example of an inner sole to be provided inside an article of footwear to be worn on a human foot. The inner sole described in Patent Literature 1 includes at least two foamed resin layers, which are to be arranged on an entire bottom surface of a shoe. The at least two foamed resin layers have a toe portion, a projecting portion, an arch portion, and a heel portion. The toe portion is formed so that t toes are placed thereon. The projecting portion is formed so that a distal end portion of a set of metatarsal bones, at which a foot has the largest width in a right-and-left direction, is placed on the projecting portion. The arch portion is formed so that a region of the foot between the metatarsal bones and an area directly below a lateral malleolus is placed on the arch portion. The heel portion is formed so that the area directly below the lateral malleolus and a calcaneus bone at the rear of the lateral malleolus are placed on the heel portion.

[0003] Further, the inner sole described in Patent Literature 1 includes a support plate. The support plate is bonded to a lower surface of a second layer of the two foamed resin layers, and is formed of a material harder than a foamed resin of the second layer. Further, the support plate described in Patent Literature 1 has an opening portion that allows a load applied by a heel to be received and absorbed by the heel portion including the first layer and the second layer. Further, in Patent Literature 2, there is described an inner sole including an area corresponding to a heel, which is designed to have a thickness smaller than that of areas on the right and left of the area corresponding to the heel.CITATION LISTPatent Literature[PTL 1] JP 7090857 B1

[0005] [PTL 2] JP 2006-102335 ASUMMARY OF INVENTIONTechnical Problem

[0006] The inventor of the present disclosure has identified a problem that the inner soles described in Patent Literature 1 and Patent Literature 2 still require improvement in order to enable a user to stand with stable posture and walk with stable posture.

[0007] An object of the present disclosure is to provide an inner sole and an article of footwear, which enable a user to stand with stable posture and walk with stable posture.Solution to Problem

[0008] According to the present disclosure, there is provided an inner sole, including a pad, the inner sole being to be provided in a foot accommodating space of an article of footwear. In plan view of the pad, the pad is divided by a center line passing through a center of the pad in a widthwise direction into an inner region and an outer region. In plan view of the pad, the inner region is a region on which a first toe of a foot is to be positioned. In plan view of the pad, the outer region is a region on which a fifth toe of the foot is to be positioned. The pad has an assist mechanism that allows a load received by a ground-contact portion of the article of footwear from a heel of the foot at a position corresponding to the outer region to exceed a load received by the ground-contact portion from the heel of the foot at a position corresponding to the inner region.

[0009] According to the present disclosure, there is provided an article of footwear, including: a main body portion under which a human foot is to be inserted; and a ground-contact portion, which is fixed to the main body portion and is to be brought into contact with a ground. In plan view of the main body portion, the main body portion is divided by a center line passing through a center of the main body portion in a widthwise direction into an inner region and an outer region. In plan view of the main body portion, the inner region is a region on which a first toe of the foot is to be positioned, and in plan view of the main body portion, the outer region is a region on which a fifth toe of the foot is to be positioned. In plan view of the main body portion, the ground-contact portion is arranged across the inner region and the outer region. The ground-contact portion has a setting mechanism that allows a load received by the ground-contact portion at a position corresponding to the outer region from a heel of the foot to exceed a load received by the ground-contact portion at a position corresponding to the inner region from the heel of the foot.Advantageous Effects of Invention

[0010] According to the inner sole of the present disclosure, a user can stand with stable posture and can walk with stable posture. According to the article of footwear having the inner sole of the present disclosure provided therein, a user can stand with stable posture and can walk with stable posture.BRIEF DESCRIPTION OF DRAWINGS

[0011] FIG. 1A is a front view of a pair of footwear, which includes inner soles, according to a first embodiment when seen from a foot heel side.

[0012] FIG. 1B is a side view of a left foot part illustrated in FIG. 1A.

[0013] FIG. 2A is a schematic plan view of the left foot part and a right foot part of the pair of footwear including inner soles according to a seventh embodiment.

[0014] FIG. 2B is a front sectional view taken along the line II-II of FIG. 2A.

[0015] FIG. 3A is a front view of a pair of footwear, which includes the inner soles, according to a second embodiment when seen from a foot heel side.

[0016] FIG. 3B is a side view of a left foot part illustrated in FIG. 3A.

[0017] FIG. 4A is a front view of a pair of footwear, which includes the inner soles, according to a third embodiment when seen from a foot heel side.

[0018] FIG. 4B is a side view of a left foot part illustrated in FIG. 4A.

[0019] FIG. 5 is a front view of a pair of footwear, which includes the inner soles, according to a fourth embodiment when seen from a foot heel side.

[0020] FIG. 6 is a front view of a pair of footwear, which includes the inner soles, according to a fifth embodiment when seen from a foot heel side.

[0021] FIG. 7 is a front view of a pair of footwear, which includes the inner soles, according to a sixth embodiment when seen from a foot heel side.

[0022] FIG. 8 is a schematic plan view of a left foot part and a right foot part of a pair of footwear including inner soles according to an eighth embodiment.

[0023] FIG. 9 is a schematic side sectional view for illustrating the inner sole, a left foot, and its skeleton.

[0024] FIG. 10 is a schematic plan view of a left foot part and a right foot part of a pair of footwear, each including a bottom portion according to a ninth embodiment.

[0025] FIG. 11 is a front sectional view taken along the line III-III of FIG. 10.DESCRIPTION OF EMBODIMENTS(Overview)

[0026] When a human stands barefoot on sand, grass, or soft earth, an outer side of a heel of a foot sinks because a calcaneus bone is positioned near an outer side of the foot. This results in a natural and spontaneous state for humans, enabling stable standing posture and stable walking. To achieve such a natural state for a user wearing a pair of footwear, for example, a pair of shoes, inner soles or outsoles of shoes are used. As a result, the user wearing the pair of footwear can have spontaneous and stable standing posture for humans. Also in walking, the user wearing the pair of footwear can walk in a way close to an ideal human gait in which a foot first lands on an outer side of the heel and then on an outer side of a set of metatarsal bones of the foot, and finally pushes off the ground with the toes.

[0027] An inner sole and an article of footwear according to the present disclosure are based on the technical idea as described above. The inner sole is fixed inside an article of footwear or can be mounted inside or removed from an article of footwear. The article of footwear is worn on a human foot for use. The inner sole is also referred to as “insole”. The article of footwear includes an upper and an outsole fixed to the upper. In the present disclosure, embodiments of the inner sole and the article of footwear are described with reference to the drawings. In the present disclosure, the same parts or portions are basically denoted by the same reference symbols in the drawings for illustrating the inner soles and the articles of footwear according to the embodiments, and a repeated description thereof is omitted.First Embodiment

[0028] FIG. 1A is a front view of a pair of footwear (pair of articles of footwear) 10 when seen from a heel side, and FIG. 2A is a plan view of the pair of footwear 10 when seen from directly above. The phrase “directly above” refers to directly above in a direction in which gravity acts. The pair of footwear 10 is, for example, a pair of leather shoes suitable for business use. The pair of footwear 10 includes a left foot part 11 to be worn on a left foot F1, and a right foot part 12 to be worn on a right foot F2, as a pair. When the pair of footwear 10 is seen in plan view, the left foot part 11 and the right foot part 12 have bilaterally symmetrical shapes. Thus, for convenience, the left foot part 11 is described as an example. The left foot part 11 includes an upper 13, an outsole 14, and an inner sole 15.

[0029] As illustrated in FIG. 1B, the upper 13 of the left foot part 11 is a main body portion for covering the left foot F1. The upper 13 is made of, for example, one of genuine leather or synthetic leather. The outsole 14 is made of, for example, one of genuine leather, synthetic leather, or a synthetic resin. The upper 13 is fixed to the outsole 14 by sewing or vulcanization bonding. The inner sole 15 is provided inside the upper 13. A combination of the upper 13 and the inner sole 15 defines a foot accommodating space 16 inside the left foot part 11.

[0030] Further, a bottom portion 64 is provided between the outsole 14 and the inner sole 15. The bottom portion 64 is also referred to as “bottom filler”. The bottom portion 64 is a sheet-shaped member made of fabric, a synthetic resin, or the like. An upper surface of the bottom portion 64 is substantially flat. When the pair of footwear 10 is seen in plan view, an outer peripheral shape of the bottom portion 64 and an outer peripheral shape of the inner sole 15 are substantially the same. The bottom portion 64 is fixed to the outsole 14. The inner sole 15 may be fixed to one of the bottom portion 64 or the outsole 14. The inner sole 15 may also be mountable onto and removable from one of the bottom portion 64 or the outsole 14. The upper 13 of the right foot part 12 is a main body portion for covering the right foot F2. A combination of the upper 13 and the inner sole 15 defines the foot accommodating space 16 inside the right foot part 12.

[0031] The inner sole 15 includes a pad 60. In plan view, the pad 60 of the left foot part 11 has a shape highly similar to that of the left foot part 11. In plan view, the pad 60 of the right foot part 12 has a shape highly similar to that of the right foot part 12. The pad 60 has a distal end 62 and a rear end 63. The distal end 62 is located at a position close to toes of a foot, and the rear end 63 is located at a position close to a heel of the foot. A lining is provided on an inner surface of the upper 13. However, illustration of the lining is omitted.

[0032] In FIG. 2A, there are illustrated two tangent lines A1 and A2, which are in contact with both ends of the left foot part 11 in a widthwise direction, and two tangent lines B1 and B2, which are in contact with both ends of the pad 60 of the inner sole 15 in the widthwise direction. When the left foot part 11 is worn on the left foot F1, the tangent line A1 is the closest to a first toe, and the tangent line A2 is the closest to a fifth toe. Further, a center line C1 lies between the two tangent lines A1 and A2. The center line C1 is an imaginary line passing through a widthwise center of the left foot part 11 and a widthwise center of the pad 60 of the inner sole 15. When the left foot part 11 is seen in plan view, the left foot part 11 is divided into an inner region D1, which is defined between the center line C1 and the tangent line A1, and an outer region D2, which is defined between the center line C1 and the tangent line A2. The four tangent lines A1, A2, B1, and B2 and the center line C1 are imaginary lines parallel to each other, that is, straight lines. The tangent line B1 lies between the center line C1 and the tangent line A1. The tangent line B2 lies between the center line C1 and the tangent line A2. The upper 13, the pad 60 of the inner sole 15, and the outsole 14 each overlap both of the inner region D1 and the outer region D2.

[0033] For the right foot part 12, when the right foot part 12 is worn on the right foot F2, the tangent line A1 is the closest to a first toe, and the tangent line A2 is the closest to a fifth toe. For the right foot part 12, the center line C1 is an imaginary line passing through a widthwise center of the right foot part 12 and a widthwise center of the inner sole 15. When the right foot part 12 is seen in plan view, the right foot part 12 is divided into the inner region D1, which is defined between the center line C1 and the tangent line A1, and the outer region D2, which is defined between the center line C1 and the tangent line A2. Further, in FIG. 2A, a skeleton of the left foot F1 and a skeleton of the right foot F2 are illustrated. Each of the skeletons includes phalanges 17, metatarsal bones 18, tarsal bones 19, and the like in the stated order from the toe toward the heel of the foot. The tarsal bones 19 include cuneiform bones, a navicular bone, and a calcaneus bone 20.

[0034] When a user stands on a predetermined surface E1 with the left foot part 11 on the left foot F1 and the right foot part 12 on the right foot F2, the outsole 14 of the left foot part 11 and the outsole 14 of the right foot part 12 are in contact with the surface E1. The surface E1 may be any of a surface of a floor, a ground surface, a surface of an asphalt road, or the like. The two outsoles 14 each include a heel portion 21. The heel portion 21 receives part of a load of a user's body from the heel of the foot, more specifically, from a position corresponding to a center of pressure on a bottom of the foot. When the left foot part 11 and the right foot part 12 are seen in plan view as illustrated in FIG. 2A, a center of pressure Q1 on the bottom of each foot is located in part of the outer region D2, in which the calcaneus bone 20 is positioned. The center of pressure Q1 is located between the distal end 62 and the rear end 63 in a direction along the center line C1.

[0035] As illustrated in FIG. 1A, which is a front view of the heel portions 21 of two outsoles 14, each of the heel portions 21 includes an inner edge 30 and a side surface 31. In plan view, the inner edge 30 is located in the inner region D1, that is, between the center line C1 and the tangent line A1. The side surface 31 is located in the outer region D2, that is, between the center line C1 and the tangent line A2. The inner edge 30 is linearly extended in a thickness direction of the outsole 14, that is, a height direction. The outsole 14 has an inclined surface 31A. The inclined surface 31A is chamfered to have a curved shape or an arc shape from the side surface 31 toward a bottom surface 31B, and is connected to the bottom surface 31B. As in both of FIG. 1A, which is a front view of the outsoles 14, and FIG. 1B, which is a side view of the outsole 14, the inclined surface 31A is inclined with respect to the bottom surface 31B. The bottom surface 31B is flat.

[0036] When the heel portion 21 of the outsole 14 is seen in front view, a thickness of part of the heel portion 21, which corresponds to the inner region D1, is substantially constant. That is, when the heel portion 21 of the outsole 14 is seen in front view, a thickness of part of the heel portion 21 in the vicinity of the side surface 31, which is located in the outer region D2, is less than a thickness of the other area of the heel portion 21. In other words, regarding stiffness against a compressive load in the thickness direction applied to each of the heel portions 21 of the outsoles 14 from a heel 50 of the left foot F1 illustrated in FIG. 1B and a heel of the right foot F2, stiffness of part of the heel portion 21, which is located in the outer region D2, is lower than stiffness of part of the heel portion 21, which is located in the inner region D1. Thus, an elastic deformation amount of the outsole 14 in the outer region D2 exceeds an elastic deformation amount of the outsole 14 in the inner region D1. That is, a load received by the outsole 14 from the heel in the outer region D2 exceeds a load received by the outsole 14 from the heel in the inner region D1. More specifically, the outsole 14 of the left foot part 11 and the outsole 14 of the right foot part 12 can each receive the load mainly at a position corresponding to the center of pressure Q1. Thus, the user can stand with stable posture and can walk and run with stable posture.

[0037] At a position on the inner sole 15, which corresponds to the outer side of the heel 50, the outsole 14 receives a load from the heel 50 in the outer region D2. When a human stands barefoot on sand, grass, or soft earth, an outer side of the heel 50 sinks because the calcaneus bone 20 is located on the outer side of the center line C1. This results in a natural and spontaneous state for humans, enabling stable standing posture and stable walking. The inner soles 15 of the pair of footwear 10 such as a pair of business shoes, which function in the same manner as inner soles each having a recess with a shape corresponding to a shape of the calcaneus bone 20 on the outer side of the heel 50, allow the outer sides of the heels 50 to sink downward as in the case in which a human stands barefoot on sand, grass, or earth. As a result, the user can have spontaneous and stable standing posture for humans. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.

[0038] More specifically, standing posture and walking posture are improved to alleviate a burden on the knees, the ankles, the low back, and the like, thus making the user more comfortable. Further, the toes can move smoothly and have a larger range of motion. Further, the pair of footwear according to this embodiment contributes to alleviation and prevention of bunions. Further, the pair of footwear according to this embodiment contributes to alleviation and prevention of splayed feet. Further, the pair of footwear according to this embodiment contributes to alleviation and prevention of floating toes. Further, the pair of footwear according to this embodiment contributes to alleviation and prevention of ingrown nails. Further, the pair of footwear according to this embodiment helps improve motor function, and thus helps exploit the potential of feet not only in simple walking and running but also in every sport. Further, the pair of footwear according to this embodiment allows sphincter muscles of the user to be squeezed, helps engage buttock muscles (gluteus maximus) of the user, and provides the user with a feeling that his / her hips are lifted up.Second Embodiment

[0039] FIG. 3A is a front view for illustrating a pair of footwear 10 according to a second embodiment. The plan view of FIG. 2A for illustrating the left foot part 11 and the right foot part 12 is used also for the pair of footwear 10 of FIG. 3A. The pair of footwear 10 illustrated in FIG. 3A is, for example, a pair of sneakers. FIG. 3B is a side view for illustrating a left foot part 11 of FIG. 3A. When heel portions 21 of two outsoles 14 are seen in front view, the heel portions 21 each include an inner edge 30 located in the inner region D1 of FIG. 2A, a side surface 32 located in the outer region D2, and a bottom surface 32A connected to the side surface 32. The bottom surface 32A is flat. In both of FIG. 3A, which is a front view of the outsoles 14, and FIG. 3B, which is a side view of the outsole 14, the side surface 32 is inclined with respect to the bottom surface 32A. A thickness of part of the outsole 14, which corresponds to the outer region D2, increases in a direction closer to the bottom surface 32A. Meanwhile, a thickness of part of the outsole 14, which corresponds to the inner region D1, is substantially constant.

[0040] That is, when the heel portion 21 of the outsole 14 is seen in front view, a thickness of part of the heel portion 21 in the vicinity of the side surface 32, which is located in the outer region D2, is less than a thickness of the other area of the heel portion 21. In other words, regarding stiffness against a compressive load in the thickness direction applied to each of the heel portions 21 of the outsoles 14 from a heel 50 of the left foot F1 illustrated in FIG. 3B and a heel of the right foot F2, stiffness of part of the heel portion 21, which is located in the outer region D2, is lower than stiffness of part of the heel portion 21, which is located in the inner region D1. Accordingly, a load received by the outsole 14 from the heel in the outer region D2 exceeds a load received by the outsole 14 from the heel in the inner region D1. Thus, the pair of footwear 10 according to the second embodiment can achieve the same effects as those of the pair of footwear 10 according to the first embodiment. The pair of footwear 10 such as a pair of business shoes has inwardly inclined portions, each corresponding to the outer side of the heel 50. With the inwardly inclined portion, the outer side of the heel 50 sinks downward as in a case in which a human stands barefoot on sand, grass, or earth. As a result, the user can have natural and spontaneous posture for humans. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.Third Embodiment

[0041] In FIG. 4A, a pair of footwear 10 according to a third embodiment is illustrated. The plan view of FIG. 2A for illustrating the left foot part 11 and the right foot part 12 is used also for the pair of footwear 10 of FIG. 4A. The pair of footwear 10 illustrated in FIG. 4A is, for example, a pair of pumps. Two outsoles 14 have raised heel portions 25 at a position corresponding to the heel of the left foot F1 and at a position corresponding to the heel of the right foot F2, respectively. The raised heel portions 25 protrude in a thickness direction of the outsoles 14, that is, a height direction. The raised heel portions 25 are each formed by, for example, covering a core of a synthetic resin with a heel cover. The raised heel portions 25 are fixed to the outsoles 14 with nails, respectively. FIG. 4B is a side view of a left foot part 11 of FIG. 4A.

[0042] In FIG. 4A, a center line C2 passing through a center of the raised heel portion 25 in a widthwise direction is illustrated. The center line C2 and the center line C1 intersect with each other at an angle of 90 degrees. The center line C2 is an imaginary line passing through a center of an upper end 29 of the raised heel portion 25 in the widthwise direction of the raised heel portion 25. The raised heel portion 25 includes side surfaces 26, 27, and 28 and a bottom surface 28A. The side surface 26 is located in the inner region D1, and is linearly extended. The side surface 26 is inclined with respect to the center line C2 so as to be closer to the center line C2 in a direction away from an upper 13. The side surfaces 27 and 28 are located in the outer region D2. The upper 13, a pad 60 of an inner sole 15, and the raised heel portion 25 each overlap both of the inner region D1 and the outer region D2.

[0043] The side surface 27 is connected to the outsole 14. The side surface 27 is inclined with respect to the center line C2 so as to be closer to the center line C2 in a direction away from the upper 13. An acute-side angle defined between an extension line of the side surface 26 and the center line C2 and an acute-side angle defined between an extension line of the side surface 27 and the center line C2 are the same. The side surface 27 is linearly extended. The side surface 28 is connected to the side surface 27 and the bottom surface 28A. In both of FIG. 4A, which is a front view of the raised heel portions 25, and FIG. 4B, which is a side view of the raised heel portion 25, the side surface 28 has a curved shape or an arc shape. The bottom surface 28A is flat. An area of part of a distal end surface, that is, a lower end surface of the raised heel portion 25 having the configuration described above, which is located in the outer region D2, is smaller than an area of part of the lower end surface of the raised heel portion 25, which is located in the inner region D1. The side surface 26 is inclined with respect to the center line C2. A connecting portion between the side surface 26 and the bottom surface 28A is illustrated as having an edge-like shape in FIG. 4A for convenience. Actually, however, the connecting portion between the side surface 26 and the bottom surface 28A is chamfered to have a curved shape or an arc shape.

[0044] When a user wears a left foot part 11 on the left foot F1 and a right foot part 12 on the right foot F2, and then stands with the lower end surfaces of two raised heel portions 25 being in contact with the surface E1, the center of pressure Q1 is located at a position on part of the raised heel portion 25, which corresponds to the outer region D2. The area of part of the distal end surface, that is, the lower end surface of the raised heel portion 25, which is located in the outer region D2, is smaller than the area of part of the lower end surface of the raised heel portion 25, which is located in the inner region D1. Thus, the left foot part 11 tends to be inclined in a direction away from the right foot part 12 in FIG. 4A. Further, the right foot part 12 tends to be inclined in a direction away from the left foot part 11 in FIG. 4A. As a result, a load received by the raised heel portion 25 from the heel in the outer region D2 exceeds a load received by the raised heel portion 25 from the heel in the inner region D1. Thus, the pair of footwear 10 according to the third embodiment can achieve the same effects as those of the pair of footwear 10 according to the first embodiment. The pair of footwear 10 such as a pair of pumps has inwardly inclined portions, each corresponding to the outer side of the heel 50. With the inwardly inclined portion, the outer side of the heel 50 sinks downward as in a case in which a human stands barefoot on sand, grass, or earth. As a result, the user can have natural and spontaneous posture for humans. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.Fourth Embodiment

[0045] In FIG. 5, a pair of footwear 10 according to a fourth embodiment is illustrated. The pair of footwear 10 according to the fourth embodiment is an example in which a width of a raised heel portion 25 is narrower than that of the raised heel portion 25 illustrated in FIG. 4A and FIG. 4B. An upper 13, a pad 60 of an inner sole 15, and the raised heel portion 25 each overlap both of the inner region D1 and the outer region D2. Further, a boundary between a side surface 28 and a bottom surface 28A lies on the center line C2. Thus, the bottom surface 28A, which is located in the inner region D1, is in contact with the surface E1, and part of the raised heel portion 25, which is located in the outer region D2, is scarcely in contact with the surface E1.

[0046] Thus, an area of the part of the raised heel portion 25, which is located in the outer region D2, is smaller than an area of part of the raised heel portion 25, which is located in the inner region D1. Accordingly, the left foot part 11 tends to be inclined in a direction in which the side surface 28 is brought closer to the surface E1. Further, the right foot part 12 tends to be inclined in a direction in which the side surface 28 is brought closer to the surface E1. As a result, a load received by the raised heel portion 25 from the heel in the outer region D2 exceeds a load received by the raised heel portion 25 from the heel in the inner region D1. The pair of footwear 10 according to the fourth embodiment can achieve the same effects as those of the pair of footwear 10 according to the first embodiment. The pair of footwear 10 such as a pair of pumps has inwardly inclined portions, each corresponding to the outer side of the heel 50. With the inwardly inclined portion, the outer side of the heel 50 sinks downward as in a case in which a human stands barefoot on sand, grass, or earth. As a result, the user can have natural and spontaneous posture for humans. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.Fifth Embodiment

[0047] FIG. 6 is a front view for illustrating a pair of footwear 10 according to a fifth embodiment. The pair of footwear 10 according to the fifth embodiment is an example in which a raised heel portion 25 has a width decreasing in a direction toward a bottom surface 26A. An upper 13, a pad 60 of an inner sole 15, and the raised heel portion 25 each overlap both of the inner region D1 and the outer region D2. A side surface 26 is located in the inner region D1, and a side surface 27 is located in the outer region D2. A distance between an upper end of the side surface 26 and the center line C2 is the same as a distance between an upper end of the side surface 27 and the center line C2. Further, an acute-side angle defined between an extension line of the side surface 26 and the center line C2 is less than an acute-side angle defined between an extension line of the side surface 27 and the center line C2. Further, the bottom surface 26A of the raised heel portion 25 is connected to the side surfaces 26 and 27. The bottom surface 26A is flat. A connecting portion between the bottom surface 26A and the side surface 26 and a connecting portion between the bottom surface 26A and the side surface 27 may each have any one of an angular shape, a curved shape, or an arc shape. The bottom surface 26A is arranged across the inner region D1 and the outer region D2.

[0048] An area of part of a distal end surface of the raised heel portion 25, that is, the bottom surface 26A, which is in contact with the surface E1 and located in the outer region D2, is larger than an area of part of the bottom surface 26A, which is in contact with the surface E1 and located in the inner region D1. As a result, a load received by the raised heel portion 25 from the heel in the outer region D2 exceeds a load received by the raised heel portion 25 from the heel in the inner region D1. Thus, the raised heel portion 25 is more likely to receive a load, which is exerted at the center of pressure Q1, in the outer region D2, and hence the pair of footwear 10 according to the fifth embodiment can achieve the same effects as those of the pair of footwear 10 according to the first embodiment. As in the example that has been described with reference to FIG. 2A, the calcaneus bone 20, which is subjected to the largest body load, is positioned on the outer side of the foot with respect to the center line C1. Thus, shifting positions of the raised heel portions 25 of the pair of footwear 10 outward in accordance with the positions of the calcaneus bones 20 allows the raised heel portions 25 of the pair of footwear 10 to effectively receive the loads. Accordingly, a burden on the ankles and the knees is alleviated, thus stabilizing the posture of the user. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.Sixth Embodiment

[0049] In FIG. 7, a pair of footwear 10 according to a sixth embodiment is illustrated. The pair of footwear 10 according to the sixth embodiment is an example in which a raised heel portion 25 has a width decreasing toward a bottom surface 26A. Further, the width of the raised heel portion 25 illustrated in FIG. 7 is less than the width of the raised heel portion 25 illustrated in FIG. 6. An upper 13, a pad 60 of an inner sole 15, and the raised heel portion 25 each overlap both of the inner region D1 and the outer region D2. Further, an acute-side angle defined between an extension line of a side surface 26 and the center line C2 and an acute-side angle defined between an extension line of a side surface 27 and the center line C2 are the same. A distance between an upper end of the side surface 26 and the center line C2 is less than a distance between an upper end of the side surface 27 and the center line C2. Accordingly, an area of part of a distal end surface of the raised heel portion 25, that is, the bottom surface 26A, which is in contact with the surface E1 and located in the outer region D2, is larger than an area of part of the bottom surface 26A, which is in contact with the surface E1 and located in the inner region D1. Thus, the raised heel portion 25 is more likely to receive a load, which is exerted at the center of pressure Q1, in the outer region D2, and hence the pair of footwear 10 according to the sixth embodiment can achieve the same effects as those of the pair of footwear 10 according to the first embodiment. As in the example that has been described with reference to FIG. 2A, the calcaneus bone 20, which is subjected to the largest body load, is positioned on the outer side of the foot with respect to the center line C1. Thus, shifting positions of the raised heel portions 25 of the pair of footwear 10 outward in accordance with the positions of the calcaneus bones 20 allows the raised heel portions 25 of the pair of footwear 10 to effectively receive the loads. Accordingly, a burden on the ankles and the knees is alleviated, thus stabilizing the posture of the user. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel 50 and then on the outer side of the set of metatarsal bones 18, and finally pushes off the ground with the toes.Seventh Embodiment

[0050] The inner soles 15 illustrated in FIG. 2A can be used for all of the pair of footwear 10 according to the first embodiment, the pair of footwear 10 according to the second embodiment, the pair of footwear 10 according to the third embodiment, the pair of footwear 10 according to the fourth embodiment, the pair of footwear 10 according to the fifth embodiment, and the pair of footwear 10 according to the sixth embodiment. As illustrated in FIG. 2B and FIG. 9, two inner soles 15 each have a pad 60, a rising portion 61 rising from an outer periphery of the pad 60, and a hole 40 extending through the pad 60 in a thickness direction. The rising portion 61 is formed so as to be curved from the outer periphery of the pad 60. Further, the rising portion 61 is formed in a region extending from an approximate center to the rear end 63 in a front-and-rear direction along the center line C1. The pads 60 are to be in contact with part of a lower surface of the heel 50 of the left foot F1 and part of a lower surface of the heel 50 of the right foot F2, respectively, and the rising portions 61 are to be in contact with part of a side surface of the heel 50 of the left foot F1 and part of a side surface of the heel 50 of the right foot F2, respectively.

[0051] When the inner sole 15 is seen in plan view, the hole 40 is formed between the approximate center and the rear end 63 of the inner sole 15 in the direction along the center line C1. When the inner sole 15 is seen in plan view, it is desired that an inner peripheral shape of the hole 40 be the same as, for example, a shape of a lower end 20A of a calcaneus bone 20 illustrated in FIG. 9, which is seen in plan view. The center of pressure Q1 is located in a region corresponding to the hole 40. When the inner sole 15 is seen in plan view, the center of pressure Q1 is located at an approximate center of the hole 40 in the direction along the center line C1. Further, when the inner sole 15 is seen in plan view, an area of part of the hole 40, which is located in the outer region D2, exceeds an area of part the hole 40, which is located in the inner region D1. When the inner sole 15 is seen in plan view, a planar shape of the part of the hole 40, which is located in the inner region D1, is, for example, a half-moon shape. When the inner sole 15 is seen in plan view, a planar shape of the part of the hole 40, which is located in the outer region D2, is, for example, a trapezoidal shape. When the inner sole 15 is seen in plan view, a rear end of the part of the hole 40, which is located in the outer region D2, is positioned between a rear end of the part of the hole 40, which is located in the inner region D1, and a rear end 63 of the pad 60. When the inner sole 15 is seen in plan view, the inner peripheral shape of the hole 40 may be one of circular, elliptical, or other shape.

[0052] Further, the hole 40 is formed so as to be partially included in the rising portion 61. An inner peripheral surface of the hole 40 is gently curved and is connected to an inner surface and an outer surface of the pad 60. When the left foot part 11 and the right foot part 12 are seen in longitudinal sectional view from a front side as illustrated in FIG. 2B, the inner peripheral surface of the hole 40 is inclined with respect to an upper surface of the bottom portion 64. The inner peripheral surface of the hole 40 is inclined in such a manner that a width of the hole 40 decreases in a direction closer to the bottom portion 64. In a longitudinal cross section of the left foot part 11 taken in a widthwise direction, an acute-side angle θ1 defined between part of the inner peripheral surface of the hole 40, which is located in the inner region D1, and the upper surface of the bottom portion 64 is less than an acute-side angle θ2 defined between part of the inner peripheral surface of the hole 40, which is located in the outer region D2, and the upper surface of the bottom portion 64. The angles θ1 and 02 are both less than 90 degrees.

[0053] Further, as illustrated in FIG. 2A and FIG. 9, a support portion 65 protruding in a thickness direction is formed on a surface of the inner sole 15. When the inner sole 15 is seen in plan view, a shape of the support portion 65 may be any one of an elliptical shape, a circular shape, or the like. In plan view of the inner sole 15, the support portion 65 may be arranged in a region on which the metatarsal bones 18 are positioned or in a region on which both the metatarsal bones 18 and the tarsal bones 19 are positioned.

[0054] Then, when a user stands on the surface E1 with the left foot part 11 on the left foot F1 and the right foot part 12 on the right foot F2, part of the lower surface of the heel 50 of the left foot F1 and part of the lower surface of the heel 50 of the right foot F2 sink down into the holes 40 of the inner soles 15, respectively. This allows twenty-eight bones of each foot to be positioned correctly for each of the left foot F1 and the right foot F2. Thus, a load received by the outsole 14 from the heel 50 in the outer region D2 exceeds a load received by the outsole 14 from the heel 50 in the inner region D1. Accordingly, the effects of the pair of footwear 10, which have been described in the first embodiment, are further enhanced.

[0055] When each of the inner soles 15 has the hole 40, the bones of each of the left foot F1 and the right foot F2 are raised, defining a gap between a lower surface of the left foot F1 and the inner sole 15 and a gap between a lower surface of the right foot F2 and the inner sole 15. Further, the support portions 65 support the lower surface of the left foot F1 and the lower surface of the right foot F2, respectively. This easily achieves an arch shape in the width direction for each of the left foot F1 and the right foot F2. Thus, impact from the ground is more easily absorbed, thus alleviating a burden on the knees, the ankles, and the low back of the user. Further, the support portions 65 are positioned in the gap between the lower surface of the left foot F1 and the inner sole 15 and the gap between the lower surface of the right foot F2 and the inner sole 15, respectively. This allows a state in which part of the lower surface of the left foot F1 and part of the lower surface of the right foot F2 sink down into the holes 40 of the inner soles 15, respectively, to be more easily maintained. Thus, the support portion 65 is effective.

[0056] Further, the inner peripheral surface of the hole 40 is inclined with respect to the upper surface of the bottom portion 64. The acute-side angle θ1 defined between the part of the inner peripheral surface of the hole 40, which is located in the inner region D1, and the upper surface of the bottom portion 64 in the widthwise direction of the left foot part 11 is less than the acute-side angle θ2 defined between the part of the inner peripheral surface of the hole 40, which is located in the outer region D2, and the upper surface of the bottom portion 64. The angles θ1 and 02 are both less than 90 degrees. Thus, the lower surface of the heel 50 is allowed to smoothly and easily sink down along the inner peripheral surface of the hole 40. In addition, the lower surface of the heel 50 is supported at a position on the inner peripheral surface of the hole 40, which is closer to the fifth toe. As a result, the heel 50 is positioned in the widthwise direction with respect to the inner sole 15.

[0057] Thus, the lower end 20A of the calcaneus bone 20 can be maintained to be positioned directly above the hole 40, allowing a load received by the heel portion 21 from the heel 50 at a position corresponding to the outer region D2, to exceed a load received by the heel portion 21 from the heel 50 at a position corresponding to the inner region D1. Accordingly, the effects of the first embodiment can be further enhanced.Eighth Embodiment

[0058] The inner soles 15 illustrated in FIG. 8 can be used for all of the pair of footwear 10 according to the first embodiment, the pair of footwear 10 according to the second embodiment, the pair of footwear 10 according to the third embodiment, the pair of footwear 10 according to the fourth embodiment, the pair of footwear 10 according to the fifth embodiment, and the pair of footwear 10 according to the sixth embodiment. Pads 60 of two inner soles 15 have cutout portions 41, respectively. The cutout portion 41 may have any appropriate shape. The center of pressure Q1 is located in a region corresponding to the cutout portion 41. An area of part of the cutout portion 41, which is located in the outer region D2, exceeds an area of part of the cutout portion 41, which is located in the inner region D1.

[0059] Then, when a user stands on the surface E1 with the left foot part 11 on the left foot F1 and the right foot part 12 on the right foot F2, part of the lower surface of the heel 50 of the left foot F1 and part of the lower surface of the heel of the right foot F2 sink down into the cutout portions 41 of the inner soles 15, respectively. Thus, a load received by the outsole 14 from the heel in the outer region D2 exceeds a load received by the outsole 14 from the heel in the inner region D1. Accordingly, the effects of the pair of footwear 10, which have been described in the first embodiment, are further enhanced.

[0060] The inner soles 15 illustrated in FIG. 2A and FIG. 8 can be provided in foot accommodating spaces of a pair of footwear, which includes outsoles without the side surface 31 being chamfered, the side surface 27, 28, or 32 being inclined, or the like. In this case, when a user stands on a surface with the left foot part on the left foot and the right foot part on the right foot, part of the lower surface of the heel of the left foot and part of the lower surface of the heel of the right foot sink down into the holes 40 or the cutout portions 41 of the inner soles 15, respectively. Thus, a load received by the outsole from the heel in the outer region D2 exceeds a load received by the outsole from the heel in the inner region D1. Accordingly, the same effects of the pair of footwear as those described in the first embodiment can be obtained.Ninth Embodiment

[0061] Both of a left foot part 11 and a right foot part 12 illustrated in FIG. 10 and FIG. 11 include no inner sole 15 described above. Bottom portions 64 of the left foot part 11 and the right foot part 12 have recessed portions 66, respectively. When the bottom portion 64 is seen in plan view from directly above, the recessed portion 66 is formed between an approximate center and a rear end 67 of the bottom portion 64 in the direction along the center line C1. An upper surface of the bottom portion 64 faces the foot accommodating space 16. The recessed portion 66 is formed in the upper surface of the bottom portion 64. The recessed portion 66 is formed by recessing part of the upper surface of the bottom portion 64 in a thickness direction of the bottom portion 64.

[0062] When the bottom portion 64 is seen in plan view, the recessed portion 66 is formed between the approximate center and the rear end 67 of the bottom portion 64 in the direction along the center line C1. When the bottom portion 64 is seen in plan view, it is desired that a shape of the recessed portion 66 be the same as, for example, the shape of the lower end 20A of the calcaneus bone 20 illustrated in FIG. 9, which is seen in plan view. The center of pressure Q1 is located in a region corresponding to recessed portion 66. When the bottom portion 64 is seen in plan view, the center of pressure Q1 is located at an approximate center of the recessed portion 66 in the direction along the center line C1. Further, when the bottom portion 64 is seen in plan view, an area of part of the recessed portion 66, which is located in the outer region D2, exceeds an area of part of the recessed portion 66 in the inner region D1. When the bottom portion 64 is seen in plan view, a planar shape of the part of the recessed portion 66, which is located in the inner region D1, is, for example, a half-moon shape. When the bottom portion 64 is seen in plan view, a planar shape of the part of the recessed portion 66, which is located in the outer region D2, is, for example, a trapezoidal shape. When the bottom portion 64 is seen in plan view, a rear end of the part of the recessed portion 66, which is located in the outer region D2, is positioned between a rear end of the part of the recessed portion 66, which is located in the inner region D1, and a rear end 67 of the bottom portion 64. When the bottom portion 64 is seen in plan view, the shape of the recessed portion 66 may be one of circular, elliptical, or other shape.

[0063] Then, when a user stands on the surface E1 with the left foot part 11 on the left foot F1 and the right foot part 12 on the right foot F2, part of the lower surface of the heel 50 of the left foot F1 and part of the lower surface of the heel 50 of the right foot F2 sink down into the recessed portions 66 of the bottom portions 64, respectively. This allows twenty-eight bones of each foot to be positioned correctly for each of the left foot F1 and the right foot F2. Thus, a load received by the outsole 14 from the heel in the outer region D2 exceeds a load received by the outsole 14 from the heel in the inner region D1. Thus, the same effects as those described in the first embodiment of the pair of footwear 10 can be obtained. The bottom portions 64 illustrated in FIG. 10 and FIG. 11 can be used for all of the pair of footwear 10 according to the first embodiment, the pair of footwear 10 according to the second embodiment, the pair of footwear 10 according to the third embodiment, the pair of footwear 10 according to the fourth embodiment, the pair of footwear 10 according to the fifth embodiment, the pair of footwear 10 according to the sixth embodiment, the pair of footwear 10 according to the seventh embodiment, and the pair of footwear 10 according to the eighth embodiment.

[0064] When each of the left foot part 11 and the right foot part 12 includes both the inner sole 15 having the hole 40 and the bottom portion 64 having the recessed portion 64, a region corresponding to the hole 40 and a region corresponding to the recessed portion 66 overlap at least partially in plan view of the inner sole 15. Further, when each of the left foot part 11 and the right foot part 12 includes both the inner sole 15 having the cutout portion 41 and the bottom portion 64 having the recessed portion 66, a region corresponding to the cutout portion 41 and the region corresponding to the recessed portion 66 overlap at least partially in plan view of the inner sole 15.(Supplementary Description)

[0065] When a human stands barefoot on sand, grass, or soft earth, the heels (outer sides) of the feet sink down because the calcaneus bones 20 are each positioned on the outer side of the center line C1, as described in the examples of FIG. 2A and FIG. 8. This allows the user to have spontaneous and correct standing posture for humans, leading to stable standing posture and stable walking. To achieve such a natural state even with a pair of footwear, the inner soles, the bottom portions, and the raised heel portions of the pair of footwear are used. As a result, the user can have spontaneous and stable standing posture for humans. Also in walking, the user can walk in a way close to an ideal gait in which a foot first lands on the outer side of the heel and then on the outer side of the set of metatarsal bones, and finally pushes off the ground with the toes. The inner soles, the pair of footwear including the outsoles, and the pair of footwear including the bottom portions according to the present disclosure can all provide the above-mentioned effects.

[0066] One example of technical meaning of the items that have been described in the embodiments is as follows. The upper 13 is one example of a main body portion. The outsole 14, the heel portion 21, and the raised heel portion 25 are each one example of a ground-contact portion. The pair of footwear 10 is one example of an article of footwear. The center line C1 is one example of a center line. The inner region D1 is one example of an inner region. The outer region D2 is one example of an outer region. The angle θ1 is one example of a first angle. The angle θ2 is one example of a second angle. The bottom portion 64 is one example of a bottom portion. The recessed portion 66 is one example of a recessed portion. The chamfer of the side surface 31, the inclined surface that forms the side surface 32, and the side surfaces 27 and 28 are each one example of a setting mechanism. The side surfaces 27, 28, 30, 31, and 32 are each one example of a side surface. The foot accommodating space 16 is one example of a foot accommodating space.

[0067] The inner sole 15 is one example of an inner sole. The pad 60 is one example of a pad. The hole 40 and the cutout portion 41 are each one example of an assist mechanism. A recessed portion or a depression may be formed in place of the hole or the cutout portion of the inner sole so that the inner sole includes a portion with a thickness smaller than that of the other portion. Further, in the drawings, elements such as the heel portion, the raised heel portion, and the outsole are illustrated as having an angular portion. However, such illustration is merely for ease of illustration. Actually, portions corresponding to the angular portions are smoothly chamfered or smoothly curved.INDUSTRIAL APPLICABILITY

[0068] The present disclosure is applicable to an inner sole to be provided in an article of footwear to be worn on a human foot, and an article of footwear.REFERENCE SIGNS LIST10 . . . pair of footwear

[0070] 13 . . . upper

[0071] 14 . . . outsole

[0072] 15 . . . inner sole

[0073] 16 . . . foot accommodating space

[0074] 21 . . . heel portion

[0075] 25 . . . raised heel portion

[0076] 27, 28, 30, 31, 32 . . . side surface

[0077] 40 . . . hole

[0078] 41 . . . cutout portion

[0079] 60 . . . pad

[0080] 64 . . . bottom portion

[0081] 66 . . . recessed portion

[0082] C1 . . . center line

[0083] D1 . . . inner region

[0084] D2 . . . outer region

[0085] θ1, θ2 . . . angle

Claims

1. An inner sole, comprising a pad, the inner sole being to be provided in a foot accommodating space of an article of footwear,wherein, in plan view of the pad, the pad is divided by a center line passing through a center of the pad in a widthwise direction into an inner region and an outer region,wherein, in plan view of the pad, the inner region is a region on which a first toe of a foot is to be positioned,wherein, in plan view of the pad, the outer region is a region on which a fifth toe of the foot is to be positioned,wherein the pad has an assist mechanism formed of a hole extending through the pad in a thickness direction, the assist mechanism allowing a load received by a ground-contact portion of the article of footwear from a heel of the foot at a position corresponding to the outer region, to exceed a load received by the ground-contact portion from the heel of the foot at a position corresponding to the inner region, andwherein the hole is formed so that a position corresponding to a center of pressure on a bottom of the foot is included in a region corresponding to the hole in plan view of the pad, and that a lower end of a calcaneus bone of the foot is positioned directly above the hole, andwherein the hole has an inner peripheral shape that is the same as a shape of the lower end of the calcaneus bone of the foot when seen in plan view.

2. The inner sole according to claim 1,wherein the hole is formed so as to have the inner peripheral shape extending across the inner region and the outer region, and an area of a first part of the hole, which is located in the outer region, exceeds an area of a second part of the hole, which is located in the inner region, a planar shape of the second part located in the inner region is a half-moon shape, and a planar shape of the first part located in the outer region is a trapezoidal shape, andwherein a rear end of the first part located in the outer region is positioned between a rear end of the second part of the hole located in the inner region and a rear end of the pad so that the hole has the inner peripheral shape that is the same as the shape of the lower end of the calcaneus bone of the foot when seen in plan view.

3. The inner sole according to claim 1, wherein the assist mechanism is formed of, in place of the hole, a recessed portion formed by recessing the pad in a thickness direction.

4. An article of footwear, comprising:a main body portion under which a human foot is to be inserted; anda ground-contact portion, which is fixed to the main body portion, and is to be brought into contact with a ground,wherein the main body portion includes:a foot accommodating space into which the foot is to be inserted; andthe inner sole of claim 1, which is provided in the foot accommodating space,wherein, in plan view of the main body portion, the main body portion is divided by a center line passing through a center of the main body portion in a widthwise direction into a main body portion inner region and a main body portion outer region,wherein, in plan view of the main body portion, the main body portion inner region is a region on which a first toe of the foot is to be positioned, and the main body portion outer region is a region on which a fifth toe of the foot is to be positioned,wherein, in plan view of the main body portion, the ground-contact portion is arranged across the main body portion inner region and the main body portion outer region,wherein the ground-contact portion has a setting mechanism that allows a load received by the ground-contact portion at a position corresponding to the main body portion outer region from a heel of the foot, to exceed a load received by the ground-contact portion at a position corresponding to the main body portion inner region from the heel of the foot, andwherein, in front view as seen from the heel of the foot, a thickness of a first part of the setting mechanism, which corresponds to the main body portion inner region, is substantially constant, and a thickness of a second part of the setting mechanism, which corresponds to the main body portion outer region, is set smaller than the thickness of the first part corresponding to the main body portion inner region.

5. The article of footwear according to claim 4, wherein, in front view as seen from the heel of the foot, the thickness of the second part of the setting mechanism, which corresponds to the main body portion outer region, increases in a direction toward the main body portion inner region.

6. The article of footwear according to claim 4, wherein the assist mechanism is formed of, in place of the hole, a recessed portion formed by recessing the pad in a thickness direction.

7. An article of footwear, comprising:a main body portion under which a human foot is to be inserted; anda ground-contact portion, which is fixed to the main body portion, and is to be brought into contact with a ground,wherein, in plan view of the main body portion, the main body portion is divided by a center line passing through a center of the main body portion in a widthwise direction into an inner region and an outer region,wherein, in plan view of the main body portion, the inner region is a region on which a first toe of the foot is to be positioned, and the outer region is a region on which a fifth toe of the foot is to be positioned,wherein, in plan view of the main body portion, the ground-contact portion is arranged across the inner region and the outer region,wherein the main body portion includes: a foot accommodating space into which the foot is to be inserted; and a bottom portion, which is fixed to the ground-contact portion and defines the foot accommodating space,wherein the bottom portion has an assist mechanism formed of a recessed portion, the assist mechanism being formed in an area facing the foot accommodating space, on which a heel of the foot is to be placed, the assist mechanism allowing a load received by the ground-contact portion of the article of footwear at a position corresponding to the outer region from the heel of the foot, to exceed a load received by the ground-contact portion of the article of footwear at a position corresponding to the inner region from the heel of the foot,wherein the recessed portion is formed so that a position corresponding to a center of pressure on a bottom of the foot is included in the recessed portion in plan view of the main body portion, and that a lower end of a calcaneus bone of the foot is positioned directly above the recessed portion, andwherein an inner peripheral shape of the recessed portion is the same as a shape of the lower end of the calcaneus bone of the foot when seen in plan view.

8. The article of footwear according to claim 7,wherein the recessed portion is formed so as to have the inner peripheral shape extending across the inner region and the outer region, and an area of a first part of the recessed portion, which is located in the outer region, exceeds an area of a second part of the recessed portion, which is located in the inner region, a planar shape of the second part located in the inner region is a half-moon shape, and a planar shape of the first part located in the outer region is a trapezoidal shape, andwherein a rear end of the first part located in the outer region is positioned between a rear end of the second part of the recessed portion located in the inner region and a rear end of the bottom portion so that the recessed portion has the inner peripheral shape that is the same as the shape of the lower end of the calcaneus bone of the foot when seen in plan view.

9. The article of footwear according to claim 7,wherein the ground-contact portion has a setting mechanism that allows a load received by the ground-contact portion at a position corresponding to the outer region from the heel of the foot, to exceed a load received by the ground-contact portion at a position corresponding to the inner region from the heel of the foot, andwherein, in front view as seen from the heel of the foot, a thickness of a first part of the setting mechanism, which corresponds to the inner region, is substantially constant, and a thickness of a second part of the setting mechanism, which corresponds to the outer region, is set smaller than the thickness of the first part corresponding to the inner region.

10. The article of footwear according to claim 9, wherein, in front view as seen from the heel of the foot, the thickness of the second part of the setting mechanism, which corresponds to the outer region, increases in a direction toward the inner region.

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