Insole

Abstract

Provided is an insole that actively allows each of the first through fifth toes to move.　An insole 1 that is to be inserted into a shoe to support a foot comprises an insole body 4 that supports the big toe ball 26A, the little toe ball 34A, and the heel bone 12 of the foot and is formed from a high-resilience material that supports the skeleton and does not allow loaded portions to sink, a cuboid bone support protrusion 2 that is provided to the insole body 4 and supports the cuboid bone 18 of the foot, and an insole front part 5 that is continuous with a tip end of the insole body 4 and is formed from a low-resilience material that allows each of the first through fifth toes of the foot to sink and grip.

Description

insole

[0001] The present invention relates to an insole.

[0002] Patent Document 1 discloses an insole having a cuboid bone supporting protrusion that supports the cuboid bone of the foot from the sole side when the insole is fitted inside a shoe.

[0003] Japanese Patent Application Laid-Open No. 2006-102335

[0004] However, the insole in Patent Document 1 is not configured to actively allow movement of each of the toes from the first to the fifth toes while walking or running. The present invention solves the above-mentioned problems of the conventional technology and provides an insole that actively allows movement of each of the toes from the first to the fifth toes.

[0005] The present invention is an insole that is fitted inside a shoe to support the foot, and comprises an insole body that supports the ball of the big toe, the ball of the little toe, and the calcaneus of the foot, supports the skeleton, and is formed of a high-resilience material to the extent that weight-bearing parts do not sink in; a cuboid bone support convex portion that is provided on the insole body and supports the cuboid bone of the foot; and an insole front portion that is continuous with the tip of the insole body and is formed of a low-resilience material to the extent that each of the first to fifth toes sinks in and can perform a gripping motion with each toe.

[0006] According to the present invention, movement of each of the first toe to the fifth toe is permitted, and the movement of gripping the insole during walking or running is achieved.

[0007] Fig. 1 is a plan view of an insole. Fig. 2 is a cross-sectional view taken along line II-II of Fig. 1. Fig. 3 is a diagram showing the foot skeleton superimposed on the insole. Fig. 4 is a diagram showing the arch of the sole of the foot.

[0008] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0009] Fig. 1 is a plan view of an insole 1 according to this embodiment. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. The insole 1 is for the left foot and has a uniform thickness T. The insole 1 for the right foot is symmetrical to that for the left foot, and therefore a description thereof will be omitted.

[0010] The insole 1 includes a solid cuboid bone support convex portion 2 that supports the cuboid bone 18 (FIG. 3) of the foot from the sole side when the insole 1 is fitted into footwear, and a solid anterior calcaneus support convex portion 3 that supports the calcaneal tuberosity 12A (FIG. 3).

[0011] 3 is a diagram showing the foot skeleton superimposed on the insole 1. The foot skeleton is shown by dashed lines. The foot skeleton is shown as seen from the back side of the insole 1, and the way the bones are superimposed is different when viewed from the front side.

[0012] The skeletal structure 10 of the foot comprises, from the heel side, the calcaneus 12, the talus 14, the navicular bone 16, the cuboid bone 18, and the first to third cuneiform bones 20, 22, and 24. The first to fifth metatarsals 26, 28, 30, 32, and 34 are located in the arch of the foot, and the foot comprises, from the toe side, 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.

[0013] For ease of explanation, in this specification, the first proximal phalange 36 and the first distal phalange 54 are referred to as the first toe, the second proximal phalange 38, the second middle phalange 46 and the second distal phalange 56 are referred to as the second toe, the third proximal phalange 40, the third middle phalange 48 and the third distal phalange 58 are referred to as the third toe, the fourth proximal phalange 42, the fourth middle phalange 50 and the fourth distal phalange 60 are referred to as the fourth toe, and the fifth proximal phalange 44, the fifth middle phalange 52 and the fifth distal phalange 62 are referred to as the fifth toe.

[0014] The anterior ends of the first to fifth metatarsals 26, 28, 30, 32, and 34 of the skeletal structure 10 are the first to fifth metatarsal heads 26A (also referred to as the ball of the foot 26A), 28A, 30A, 32A, and 34A (also referred to as the ball of the little foot 34A). The stepped portion located in the front of the calcaneus 12 on the heel side is the anterior part of the calcaneus (also referred to as the calcaneal tuberosity) 12A.

[0015] The cuboid bone support convex portion 2 supports the foot with the cuboid bone 18 as a fulcrum, and applies maximum stress to the sole of the foot corresponding to the cuboid bone 18 to allow the foot to move around the convex portion 2, and gradually reduces the stress acting on the sole of the foot from the area corresponding to the cuboid bone 18 toward both side edges, including the area corresponding to the navicular bone 16.

[0016] In other words, the cuboid support convex portion 2 supports the foot with the cuboid bone 18 as a fulcrum, and applies maximum stress to the sole of the foot corresponding to the cuboid bone 18 so as to allow the foot to move around the convex portion 2, and gradually reduces the stress acting on the sole of the foot from the area corresponding to the cuboid bone 18 toward both side edges of the insole 1, including the area corresponding to the navicular bone 16. As a result, the stress acting on the sole of the foot gradually decreases from the front to the back.

[0017] The insole 1 includes an insole body 4 and an insole front part 5. The insole body 4 and the insole front part 5 are joined together by bonding with, for example, an adhesive.

[0018] The insole body 4 supports the area including the ball of the big toe 26A, the ball of the little toe 34A, and the calcaneus 12 from the sole of the foot, supporting the human skeleton. The front edge 4A of the insole body 4 is convexly curved, including the area 4B on which the ball of the big toe 26A rests and the area 4C on which the ball of the little toe 34A rests. The front edge 4A of the insole body 4 is convexly curved, connecting approximately the middle parts of the proximal phalanges 36, 38, 40, 42, and 44. The insole body 4 is made of a high-resilience material. The high-resilience material has a hardness that prevents the weight-bearing area from sinking.

[0019] For example, the high-resilience material is urethane foam. The hardness of the high-resilience material is preferably an Asker C hardness of 35 or more. A specific example of the high-resilience material that can be used is PORON (registered trademark) FW-27.

[0020] The insole front part 5 is formed to include a region 5B on which the first distal phalanx 54 of the foot rests and a region 5C on which the fifth distal phalanx 62 rests. The rear edge 5A of the insole front part 5 is curved concavely, and the front edge 4A of the insole body 4 fits into the rear edge 5A. Like the front edge 4A of the insole body 4, the rear edge 5A of the insole front part 5 is curved to connect approximately the middle parts of the proximal phalanxes 36, 38, 40, 42, and 44 of the foot.

[0021] The front insole portion 5 has a so-called horseshoe shape. That is, the front edge of the front insole portion 5 is convexly curved to form a toe portion. The rear edge 5A of the front insole portion 5 is concavely curved. One end (on the right side in FIG. 3 ) of the concave rear edge 5A curves to surround the ball of the big toe 26A. The other end (on the left side in FIG. 3 ) of the rear edge 5A curves to surround the ball of the little toe 34A. The front insole portion 5 supports the distal phalanges 54, 56, 58, 60, and 62 of the foot from the sole side. This actively allows movement of the first and fifth toes, making it easier for the first through fifth toes to grip the ground.

[0022] The inventors have discovered that when the insole body 4 is made of a high-resilience material and the cuboid bone support convex portion 2 supports the foot with the cuboid bone 18 as a fulcrum and allows the foot to move around the convex portion 2, by appropriately selecting the material of the insole front portion 5, it becomes even easier for each of the first toe to grip the ground.

[0023] The insole front portion 5 is made of a low-resilience material. For example, the low-resilience material is urethane foam, which has a weaker resilience than the high-resilience material of the insole body 4. Specifically, the hardness of the low-resilience material is an Asker C hardness that is 5 or more smaller than the Asker C hardness of the high-resilience material. In other words, the low-resilience material is such that the difference between the Asker C hardness of the high-resilience material and the Asker C hardness of the low-resilience material is 5 or more. By having a difference of 5 or more between the Asker C hardness of the high-resilience material and the Asker C hardness of the low-resilience material, it becomes easier for the toes to sink into the insole front portion 5. A specific example of a low-resilience material that can be used is TM-15 by PORON (registered trademark).

[0024] In this embodiment, with the cuboid bone support protrusion 2 supporting the cuboid bone 18, the first to fifth toes resting on the insole front part 5 sink into the low-resilience material insole front part 5. This allows the first to fifth toes to grip the ground with the cuboid bone 18 supported.

[0025] 4 shows the arch of the sole of the foot. When walking or running, an arch 119 (schematically shown by a broken line) is formed in the sole of the human foot in a natural state.

[0026] The arch 119 includes a medial longitudinal arch 121 and a lateral longitudinal arch 122 formed in the longitudinal direction of the foot, and a transverse arch 120 formed in the lateral direction of the foot. Referring to FIG. 1 , the transverse arch 120 is formed across the first to fifth metatarsals 26 to 34. The medial longitudinal arch 121 is formed across the calcaneus 12, talus 14, navicular bone 16, three cuneiform bones 20 to 24, and first to third metatarsals 26 to 30. The lateral longitudinal arch 122 is formed across the calcaneus 12, cuboid bone 18, and fourth and fifth metatarsals 32, 34.

[0027] The calcaneus 12 simultaneously constitutes both the medial longitudinal arch 121 and the lateral longitudinal arch 122, and therefore if the calcaneus 12 is not stable, the longitudinal arches cannot be maintained in their normal positions.

[0028] In this embodiment, the anterior calcaneal support convexity 3 supports the calcaneal tuberosity 12A via the long plantar ligament, stabilizing the calcaneus 12, reducing distortion of the calcaneocuboid joint, and maintaining the longitudinal arch in its normal position. The anterior calcaneal support convexity 3 includes a portion corresponding to the calcaneal tuberosity 12A where the long plantar ligament overlaps. At night, the function of maintaining the longitudinal arch is reduced compared to daytime, but in this embodiment, the longitudinal arch functions more effectively as a spring, reducing distortion of the calcaneocuboid joint and maintaining the longitudinal arch in its normal position, even at night.

[0029] The anterior calcaneal support convexity 3 not only supports the long plantar ligament and promotes passive stabilization of the foot arch, but also supports the insertion tendon of the peroneus longus muscle, which is important for active stabilization of the lateral longitudinal arch via the long plantar ligament. Here, passive stability is achieved by ligaments, and active stability is achieved by muscles (tendons). The insertion tendon wraps around the cuboid bone 18, crosses the sole of the foot from the lateral edge, and inserts at the bottom of the first cuneiform bone 20 and the first metatarsal bone 26.

[0030] A portion of the anterior support convexity 3 of the calcaneus is located below the cuboid bone 18 and supports the navicular bone 16 via the cuboid bone 18. This indirectly supports the insertion tendon of the tibialis posterior muscle, which is the main active stabilizing structure of the medial longitudinal arch. The insertion tendon of the tibialis posterior muscle extends through the fascia to the first to third cuneiform bones 20-24, the second to third metatarsals 28, 30, and the navicular bone 16. The oblique course of the peroneus longus and tibialis posterior muscles maintains the longitudinal arch in addition to the transverse arch.

[0031] In this embodiment, the material of the insole body 4 has a stronger resilience than the material of the insole front portion 5, and has a hardness that prevents sinking in the weight-bearing area, thereby providing firm support for the human body's skeleton. Furthermore, because the insole front portion 5 is made of a low-resilience material with weak resilience, each of the first to fifth toes can grip the ground, allowing each toe to train, for example, simply by wearing the insole and walking. Furthermore, because the insole body 4 includes the cuboid bone support protrusions 2, the skeletal balance of the foot is improved, further improving stability and mobility. Because the insole body 4 is made of a high-resilience material and the cuboid bone support protrusions 2 are also made of the same material, the cuboid bone 18 of the foot can be firmly supported.

[0032] In this embodiment, the front insole 5 has a horseshoe shape, with one end of the rear edge 5A of the front insole 5 curving to surround the ball of the big toe 26A and the other end of the rear edge 5A curving to surround the ball of the little toe 34A. This actively allows movement of each of the first toe to the fifth toe, making it easier to grip the front insole 5 with each toe.

[0033] In this embodiment, the cuboid support convex portion 2 is configured to relieve stress, thereby allowing movement of the joint formed by the calcaneus 12. The apex of the anterior calcaneus support convex portion 3 sinks when weight is applied. As the apex of the convex portion 3 sinks, the cuboid bone 18 is supported around the cuboid support convex portion 2. The insole 1 has the function of supporting the foot with the cuboid bone 18 as a fulcrum and allowing movement of the foot around the cuboid support convex portion 2.

[0034] In this embodiment, the anterior calcaneus support convexity 3 abuts against the calcaneal tuberosity (the anterior part of the calcaneus) 12A, maintaining the medial longitudinal arch 121, lateral longitudinal arch 122, and transverse arch 120. The anterior calcaneus support convexity 3 can stably support the calcaneus 12, maintaining the natural shapes of the transverse arch 120, medial longitudinal arch 121, and lateral longitudinal arch 122 of the sole, thereby improving the stability and mobility of the foot.

[0035] The cuboid bone support protrusions 2 support the cuboid bone 18, which helps maintain the arch shape of the sole of the foot and reduces fatigue when walking, running, etc. In addition, the cuboid bone support protrusions 2 are inclined slightly radially from the apex, making it easier for the foot to move back and forth and side to side, providing footwear that reduces fatigue.

[0036] The above-described embodiment is one aspect of the present invention, and it goes without saying that it can be modified as appropriate within the scope of the present invention.

[0037] For example, in the above embodiment, the thickness T of the insole 1 is uniform, but this is not limiting and the thickness T may be gradually thinner from the rear portion to the front portion, for example.

[0038] The insole 1 is integrally joined by bonding the front edge of the insole body 4 and the rear edge of the insole front part 5 with an adhesive or the like, but is not limited to this. For example, the insole body 4 and the insole front part 5 may be formed by so-called two-color molding. Furthermore, although not shown in the drawings, the insole body 4 and the insole front part 5 may be placed on another sheet (not shown) and then bonded to the other sheet with an adhesive or the like to form an integral unit.

[0039] The insole 1 of the present invention is suitable for a wide variety of footwear, including not only footwear for everyday use, but also medical footwear for treatment and rehabilitation purposes, and training footwear for health promotion purposes.

[0040] [Configurations Supported by the Above-described Embodiments] The above-described embodiments support the following configurations.

[0041] (Configuration 1) An insole that is fitted inside a shoe to support the foot, comprising: an insole body that supports the ball of the big toe, the ball of the little toe, and the calcaneus of the foot, supporting the skeleton and preventing weight-bearing areas from sinking; a cuboid bone support protrusion that is provided on the insole body and supports the cuboid bone of the foot; and an insole front portion that is continuous with the tip of the insole body and is made of a low-resilience material that allows each of the first toe through the fifth toe to sink in and grip with the toes. This insole actively allows movement of each of the first toe through the fifth toe when walking or running.

[0042] (Configuration 2) The insole according to Configuration 1, wherein the front edge of the insole body is convexly curved including the areas on which the balls of the big toe and little toe rest, and the rear edge of the insole front part is concavely curved including the areas on which the first and fifth distal phalanges rest, and the front edge of the insole body fits into the rear edge of the insole front part. This actively allows movement of the first and fifth toes of the foot, making it easier to grip the ground with the first to fifth toes.

[0043] (Configuration 3) The insole according to Configuration 1 or 2, wherein the front part of the insole is horseshoe-shaped. This actively allows movement of the first and fifth toes, making it easier for the first to fifth toes to grip the ground.

[0044] (Configuration 4) The insole according to any one of Configurations 1 to 3, wherein the rear edge of the front part of the insole is concavely curved, one end of the rear edge is curved to surround the ball of the big toe, and the other end is curved to surround the ball of the little toe. This actively allows movement of the first and fifth toes, making it easier for the first to fifth toes to grip the ground.

[0045] (Configuration 5) The insole according to any one of Configurations 1 to 4, wherein the difference in Asker C hardness between the high-resilience material and the low-resilience material is at least 5. With this, the difference in hardness between the insole body and the front part of the insole makes it easier for the toes of the first to fifth toes to sink into the insole body, making it easier for the first to fifth toes to grip the ground.

[0046] (Configuration 6) The insole according to Configuration 5, wherein the high-resilience material has an Asker C hardness of 35 or more. This actively allows movement of the first and fifth toes, making it easier for the first to fifth toes to grip the ground.

[0047] 1 Insole 2 Cuboid support convexity 3 Anterior calcaneus support convexity 4 Insole body 4A Anterior edge 5 Anterior insole 5A Posterior edge 12 Calcaneus 12A Anterior calcaneus (calcaneal tuberosity) 16 Navicular bone 18 Cuboid bone 20, 22, 24 Cuneiform bone 26, 28, 30, 32, 34 Metatarsal 26A Metatarsal head (ball of the big toe) 34A Metatarsal head (ball of the little toe) 36, 38, 40, 42, 44 Proximal phalanx 46, 48, 50, 52 Middle phalanx 54, 56, 58, 60, 62 Distal phalanx

Claims

1. An insole that is fitted inside a shoe to support the foot, comprising: an insole body that supports the ball of the big toe, the ball of the little toe, and the calcaneus of the foot, supporting the skeleton and preventing weight-bearing parts from sinking; a cuboid bone support convex portion that is provided on the insole body and supports the cuboid bone of the foot; and an insole front portion that is continuous with the tip of the insole body and is made of a low-resilience material that allows each of the first to fifth toes to sink in and perform a gripping motion with each toe.

2. The insole according to claim 1, wherein the front edge of the insole body is convexly curved to include the areas on which the balls of the big toe and little toe rest, and the rear edge of the insole front part is concavely curved to include the areas on which the first and fifth distal phalanges rest, and the front edge of the insole body fits into the rear edge of the insole front part.

3. The insole according to claim 1 or 2, wherein the front part of the insole is horseshoe-shaped.

4. The insole according to claim 1 or 2, wherein the rear edge of the front part of the insole is concavely curved, one end of the rear edge curves to surround the ball of the big toe, and the other end curves to surround the ball of the little toe.

5. The insole according to claim 1, wherein the difference between the Asker C hardness of the high-resilience material and the Asker C hardness of the low-resilience material is 5 or more.

6. The insole according to claim 5, wherein the high-resilience material has an Asker C hardness of 35 or more.

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