HUGHES, Brian (700 Alta Avenue, San Antonio, TX, 78209, US)
DANANBERG, Howard, J. (19 Beaver Lane, Bedford, New Hampshire, 03110, US)
HUGHES, Brian (700 Alta Avenue, San Antonio, TX, 78209, US)
| What is claimed is; 1. A human shoe sole having a foot supporting upper surface including a first region for supporting the first, second, third, fourth and optionally fifth metatarsal heads of the foot, and a second region surrounding the first region for supporting the remainder of the foot, at least in part, wherein the first region provides less resistance to downward motion than the second region, wherein the first region includes a hollow or depressed area relative to the remainder of the first region having a medial border portion and a lateral border portion, wherein the depression has its lowest point skewed to the medial side of center, whereby to promote eversion of the first metatarsal head as the wearer moves from midstance through propulsive phase. 2. The human shoe sole of claim 1 , wherein the first region has a lower durometer than the second region. 3. The shoe sole according to claim 2, wherein the first region has a Short A hardness of 30-35. 4. The shoe sole according to any of claims 1 -3, wherein the first region is formed of a plug of material surrounded by the second region. 5. The shoe sole according to any of claims 1-3, wherein the depressed area comprises an opening formed in the sole and extending from the upper surface thereof. 6. The shoe sole according to any of claims 1-3, wherein the depression comprises a hollow formed below the upper surface of the sole. 7. The shoe sole according to any of claims 1 -6, wherein the depression has a normal depth of 2-3 mm measured from a top edge of a side wall to the lowest point of the depression. 8. The shoe sole according to any of claims 1 -7, wherein the depression is substantially circular in plan. 9. The shoe sole according to any of claims 1-7, wherein the depression is oval or egg-shaped in plan. 10. The shoe sole according to claim 9, wherein the depression is elongated and slightly wider at its toeward end. 1 1. An insole for insertion into a human shoe having a foot supporting upper surface including a first region for supporting the first, second, third, fourth and optionally fifth metatarsal heads of the foot, and a second region surrounding the first region for supporting the remainder of the foot, at least in part, wherein the first region provides less resistance to downward motion than the second region, wherein the first region includes a hollow or depressed area relative to the remainder of the first region having a medial border portion and a lateral border portion, wherein the depression has its lowest point skewed to the medial side of center, whereby to promote eversion of the first metatarsal head as the wearer moves from midstance through propulsive phase. 12, The insole of claim 1 1, wherein the first region has a lower durometer than the second region. 13. The insole according to claim 12, wherein the first region has a Shore A hardness of 30-35. 14. The insole according to any of claims 1 1 -13, wherein the first region is formed of a plug of material surrounded by the second region. 15. The insole according to any of claims 1 1 -13, wherein the depressed area comprises an opening formed in the sole and extending from the upper surface thereof. 16. The insole according to any of claims 11-13, wherein the depression comprises a hollow formed below the upper surface of the insole. 17. The insole according to any of claims 1 1 -16, wherein depression has a normal depth of 2-3 mm measured from a top edge of a side wall to the lowest point of the depression. 18. The insole according to any of claims 1 1-17, wherein the depression is substantially circular in plan. 19. The insole according to any of claims 1 1 -17, wherein the depression is oval or egg-shaped in plan. 20. The insole according to claim 19, wherein the depression is elongated and slightly wider at its toeward end. 21. A sockliner for insertion into a human shoe having a foot supporting upper surface including a first region for supporting the first, second, third, fourth and optionally fifth metatarsal heads of the foot, and a second region surrounding the first region for supporting the remainder of the foot, at least in part, wherein the first region provides less resistance to downward motion than the second region, wherein the first region includes a hollow or depressed area relative to the remainder of the first region having a medial border portion and a lateral border portion, wherein the depression has its lowest point skewed to the medial side of center, whereby to promote eversion of the first metatarsal head as the wearer moves from midstance through propulsive phase. 22. The sockliner of claim 21 , wherein the first region has a lower durometer than the second region. 23. The sockliner according to claim 22, wherein the first region has a Shore A hardness of 30-35. 24. The sockliner according to any of claims 21 -23, wherein the first region is formed of a plug of material surrounded by the second region. 25. The sockliner according to any of claims 21 -23, wherein the depressed area comprises an opening formed in the sole and extending from the upper surface thereof. 26. The sockliner according to any of claims 21 -23, wherein the depression comprises a hollow formed below the upper surface of the sockliner. 27. The sockliner according to any of claims 21 -26, wherein the normal depth of 2-3 mm measured from a top edge of a side wall to the lowest point of the depression. 28. The sockliner according to any of claims 21 -27, wherein the depression is substantially circular in plan. 29. The sockliner according to any of claims 21 -27, wherein the depression is oval or egg-shaped in plan. 30. The sockliner according to claim 29, wherein the depression is elongated and slightly wider at its toeward end. 31. An orthotic for insertion into a human shoe sole having a foot supporting upper surface including a first region for supporting the first, second, third, fourth and optionally fifth metatarsal heads of the foot, and a second region surrounding the first region for supporting the remainder of the foot, at least in part, wherein the first region provides less resistance to downward motion than the second region, wherein the first region includes a hollow or depressed area relative to the remainder of the first region having a medial border portion and a lateral border portion, wherein the depression has its lowest point skewed to the medial side of center, whereby to promote eversion of the first metatarsal head as the wearer moves from midstance to propulsive phase. 32. The orthotic of claim 31 , wherein the first region has a lower durometer than the second region. 33. The orthotic according to claim 32, wherein the first region has a Shore A hardness of 30-35. 34. The orthotic according to any of claims 31 -33, wherein the first region is formed of a plug of material surrounded by the second portion, 35. The orthotic according to any of claims 31-33, wherein the depressed area comprises an opening formed in the sole and extending from the upper surface thereof. 36. The orthotic according to any of claims 31-33, wherein the depression comprises a hollow formed below the upper surface of the insole. 37. The orthotic according to any of claims 31-36, wherein the depression has normal depth of 2-3 mm measured from a top edge of a side wall to the lowest point of the depression. 38. The orthotic according to any of claims 31 -37, wherein the depression is substantially circular in plan. 39. The orthotic according to any of claims 31 -37, wherein the depression is oval or egg-shaped in plan. 40. The orthotic according to claim 39, wherein the depression is elongated and slightly wider at its toeward end. 41. The orthotic of claim 31 , wherein the orthotic is a custom orthotic. 42. The orthotic of claim 31 , wherein the orthotic is a prefabricated orthotic. 43. A human shoe sole having a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. 44. The shoe sole of claim 43, including a footbed, a lateral arch region, a medial arch region and a heel region, wherein the footbed and the lateral arch region have a first hardness value, the medial arch region has a second hardness value that is softer than the first hardness value, and the heel region has a third hardness value that is harder than the first and second hardness values. 45. The shoe sole of claim 44, wherein the lateral arch region has a Shore C hardness value of 20 to 60. 46. The shoe sole of claim 44, wherein the lateral arch region has a Shore C hardness of about 40. 47. The shoe sole of claim 44, wherein the medial arch region has a Shore C hardness of about 15 to 55. 48. The shoe sole of claim 44, wherein the medial arch region has a Shore C hardness of about 35. 49. The shoe sole of claim 44, wherein the heel region has a Shore C hardness of about 30 to 70. 50. The shoe sole of claim 44, wherein the heel region has a Shore C hardness of about 50. 51. The shoe sole of any of claims 44-50, wherein the footbed includes a forward region which includes a hollow or depression underlying the first metatarsal head of the wearer. 52. The shoe sole of any of claims 44-51 , wherein the medial arch region has a second hardness value that is at least 5 Shore C points softer than the first hardness value, but not more than 10 Shore C points softer, and the heel region has a third hardness value that is at least 10 Shore C points harder than the first hardness values, but not more than 20 Shore C points harder. 53. An insole for insertion into a human shoe having a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. 54. The insole of claim 53, including a footbed, a lateral arch region, a medial arch region and a heel region, wherein the footbed and the lateral arch region have a first hardness value, the medial arch region has a second hardness value that is softer than the first hardness value, and the heel region has a third hardness value that is harder than the first and second hardness values. 55. The insole of claim 54, wherein the lateral arch region has a Shore C hardness value of 20 to 60. 56. The insole of claim 54, wherein the lateral arch region has a Shore C hardness of about 40. 57. The insole of claim 54, wherein the medial arch region has a Shore C hardness of about 15 to 55. 58. The insole of claim 54, wherein the medial arch region has a Shore C hardness of about 35. 59. The insole of claim 54, wherein the heel region has a Shore C hardness of about 30 to 70. 60. The insole of claim 54, wherein the heel region has a Shore C hardness of about 50. 61. The insole of claim 53-60, wherein the footbed includes a forward region which includes a hollow or depression underlying the first metatarsal head of the wearer. 62. The insole of claim 54, wherein the medial arch region has a second hardness value that is at least 5 Shore C points softer than the first hardness value, but not more than 10 Shore C points softer, and the heel region has a third hardness value that is at least 10 Shore C points harder than the first hardness values, but not more than 20 Shore C points harder. 63. A sockliner for insertion in a human shoe having a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. 64. The sockliner of claim 63, including a footbed, a lateral arch region, a medial arch region and a heel region, wherein the footbed and the lateral arch region have a first hardness value, the medial arch region has a second hardness value that is softer than the first hardness value, and the heel region has a third hardness value that is harder than the first and second hardness values. 65. The sockliner of claim 64, wherein the lateral arch region has a Shore C hardness value of 20 to 60. 66. The sockliner of claim 64, wherein the lateral arch region has a Shore C hardness of about 40. 67. The sockliner of claim 64, wherein the medial arch region has a Shore C hardness of about 15 to 55. 68. The sockliner of claim 64, wherein the medial arch region has a Shore C hardness of about 35. 69. The sockliner of claim 64, wherein the heel region has a Shore C hardness of about 30 to 70. 70. The sockliner of claim 64, wherein the heel region has a Shore C hardness of about 50. 71. The sockliner of any of claims 62-70, wherein the footbed includes a forward region which includes a hollow or depression underlying the first metatarsal head of the wearer. 72. The sockliner of claim 64, wherein the medial arch region has a second hardness value that is at least 5 Shore C points softer than the first hardness value, but not more than 10 Shore C points softer, and the heel region has a third hardness value that is at least 10 Shore C points harder than the first hardness values, but not more than 20 Shore C points harder. 73. An orthotic for insertion into a human shoe having a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. 74. The orthotic of claim 73, including a footbed, a lateral arch region, a medial arch region and a heel region, wherein the footbed and the lateral arch region have a first hardness value, the medial arch region has a second hardness value that is softer than the first hardness value, and the heel region has a third hardness value that is harder than the first and second hardness values. 75. The orthotic of claim 74, wherein the lateral arch region has a Shore C hardness value of 20 to 60. 76. The orthotic of claim 74, wherein the lateral arch region has a Shore C hardness of about 40. 77. The orthotic of claim 74, wherein the medial arch region has a Shore C hardness of about 15 to 55. 78. The orthotic of claim 74, wherein the medial arch region has a Shore C hardness of about 35. 79. The orthotic of claim 74, wherein the heel region has a Shore C hardness of about 30 to 70. 80. The orthotic of claim 74, wherein the heel region has a Shore C hardness of about 50. 81. The orthotic of any of claims 72-80, wherein the footbed includes a forward region which includes a hollow or depression underlying the first metatarsal head of the wearer. 82. The orthotic of claim 74, wherein the medial arch region has a second hardness value that is at least 5 Shore C points softer than the first hardness value, but not more than 10 Shore C points softer, and the heel region has a third hardness value that is at least 10 Shore C points harder than the first hardness values, but not more than 20 Shore C points harder. 83. An insole board for a human shoe having a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. 84. The insole board of claim 83, including a footbed, a lateral arch region, a medial arch region and a heel region, wherein the footbed and the lateral arch region have a first hardness value, the medial arch region has a second hardness value that is softer than the first hardness value, and the heel region has a third hardness value that is harder than the first and second hardness values. 85. The insole board of claim 84, wherein the lateral arch region has a Shore C hardness value of 20 to 60. 86. The insole board of claim 82, wherein the lateral arch region has a Shore C hardness of about 40. 87. The insole board of claim 82, wherein the medial arch region has a Shore C hardness of about 15 to 55. 88. The insole board of claim 82, wherein the medial arch region has a Shore C hardness of about 35. 89. The insole board of claim 82, wherein the heel region has a Shore C hardness of about 30 to 70. 90. The insole board of claim 82, wherein the heel region has a Shore C hardness of about 50. 91. The insole board of any of claims 82-90, wherein the footbed includes a forward region which includes a hollow or depression underlying the first metatarsal head of the wearer. 92. The insole board of claim 82, wherein the medial arch region has a second hardness value that is at least 5 Shore C points softer than the first hardness value, but not more than 10 Shore C points softer, and the heel region has a third hardness value that is at least 10 Shore C points harder than the first hardness values, but not more than 20 Shore C points harder. |
This invention relates generally to footwear and, more particularly to insoles for footwear having features that improve the comfort for the wearer during standing, walking and running.
Footwear has undergone significant evolutionary advances in technology, particularly since the development of the electrodynogram which has permitted researchers to measure dynamic forces and to better understand biomechanical action of a human foot within a shoe while the wearer is walking or running. Using this tool, many researchers have made technological advances directed towards the mid-sole of a shoe. Since the mid-sole functions primarily as a suspension system of the sole of the foot, and often provides both protective cushioning and a stable platform for the wearer's foot, many conventional technologies have focused on cushioning the impact associated with foot strike by varying the spring coefficients in the mid-sole to dispense shock.
In my earlier U.S. Patent 4,597,195 I describe a discovery of a then previously misunderstood phenomena, functional hallux limitus, that is believed to affect a majority of the population. To treat functional hallux limitus I created an improved shoe sole design which permits the first metatarsal to better achieve plantarflex relative to the great toe and remaining metatarsal heads. As explained in my aforesaid ' 195 patent, plantarflex allows for the extension of the human great toe during human gate cycle in an efficient fashion. More particularly in accordance with my prior ' 195 patent, 1 created a human shoe sole having an area of reduced support underlying substantially only the location of the first metatarsal head of the wearer's foot. As described in my ' 195 patent, providing an area of reduced support substantially only under the head of the first metatarsal encourages eversion and plantarflexion of the first metatarsal head as weight shifts from the heel to the first ray. Thus the normal functioning of the foot for plantarflexion and supination is encouraged with beneficial results for improved walking comfort and shock absorption on subsequent heel contact. Following my discovery millions of pairs of shoes have been manufactured with foot beds having an area of reduced support underlying substantially only the location of the first metatarsal head of the wearer's foot, to encourage plantarflexion of the first metatarsal head. The present invention provides an improved insole which incorporates an area of reduced support which includes an asymmetrically shaped depression under the first metatarsal head, fashioned with its lowest point skewed to the medial side of center. This unique shape further encourages the first metatarsal head into eversion as the wearer moves from midstance to propulsive phase.
As used herein the term "sole" and "inner sole" are used interchangeably. Moreover, a "sole" or "insole" may be an element built into or forming an integral element of a footwear product such as an insole board, or as a separate element, including, e.g. a sock liner or removable insole, an after-market insole device, or a custom or prefabricated foot orthotic, which may be inserted into a footwear product post-manufacture. The element also may be cut into or formed in the foot supporting surface of a shoe.
In one aspect, the improved footwear of this invention comprises a sole having a forefoot section having a first region for supporting the first, second, third, fourth and optionally fifth metarsal heads of the foot and a second region surrounding the first region, for supporting the remainder of the foot, at least in part. The first region is designed to provide less support than portions surrounding the second region. Typically, the sole is formed so that the first region is formed of a resiliently deformable material that has a lower durometer or resistance to movement than the second region. Also, in order to further promote eversion, an area of the first region underlying substantially only the first metatarsal head has a depression relative to the surrounding portion having an asymmetric shape with its lowest point skewed to the medial side of center. In other words, the depression has a shallower slope on the lateral side. This has the effect of rotating the first metatarsal head into eversion as the wearer moves from midstance to propulsive phase. The remainder of the first region preferably is flat.
In another aspect, the present invention provides further improvements in insoles for footwear which can be used alone or in combination with a depression under the metatarsal as described in my earlier ' 195 patent and as described above. More particularly, we have discovered that additional comfort and biomechanical efficiency can be achieved by providing a foot supporting upper surface having regions of varying hardness that approximately match the regions of varying hardness of the underside of the wearer's foot. Properly executed, this results in mechanical impedance matching between the surface of the wearer's foot and the surface of the insole, such that the differential velocity between the two surfaces is minimized.
Further features and advantages of the present invention will be seen from the following detailed description, taking in conjunction with the accompanying drawings, wherein:
FIG. 1 is a top plan view of a sole incorporating an insert according to a first embodiment of my present invention for the right foot;
FIG. IA is a top plan view showing details of an insert element, with contour lines taken at 0.3 cm superimposed thereon, according to the first embodiment;
FIGs. 2A-2C are cross-sectional views taken along lines UA-IIC of FIG. 1 ; FIG. 2D is a cross-sectional view taken along lines IID of Fig. 1 ;
FIG. 3 is a top plan view, and FIG. 4 a transparent perspective view, with contour lines taken at 0.3 cm superimposed thereon, showing details of portions of a second embodiment of the insert element of my invention;
FIG. 5 is a cross-sectional view showing a third embodiment of my invention; and
FIG. 6 is a perspective view of a sole according to a fourth embodiment of my invention.
Referring to FIGs. 1, IA and 2A-D of the drawings, footwear made in accordance with the present invention includes a sole, designated reference numeral 10, having a heel section 12, an arch section 14, a forefoot section 16 and a toe section 18, corresponding to parts of a wearer's foot. In use, the heel section 12 underlies the heel of the wearer's foot and includes medial and lateral regions designated 20, 22, respectively corresponding to the inner and outer sides of the foot. Likewise, the arch section 14 which is forward the heel section 12, underlies the arch of the wearer's foot and also includes medial and lateral regions 24, 26, respectively. The forefoot section 16 is forward the arch section 14 and includes the so-called ball of the foot which includes the first, second, third, fourth and fifth metatarsals indicated in phantom at M1 -M5. The ball of the foot also includes first, second, third, fourth and fifth metatarsal heads (N1 -N5) associated with the respective first, second, third, fourth and fifth metatarsal heads, and first, second, third, fourth and fifth proximal phalanges (PP1-PP5) forward of the respective first, second, third, fourth and fifth metatarsal heads, and associated metatarsal first, second, third, fourth and fifth metatarsal phalangeal joints (not labeled) between the associated metatarsal heads and proximal phalageals. The forefoot section 16 is divided into first and second regions designated 28 and 30, respectively. The first region 28 is adapted to underlie the first, second, third, and fourth metatarsal heads and optionally the fifth metatarsal head, in part, while the second region 30 is adapted to underlie the proximal phalanges (PPl -PP5), at least in part. The toe section 18 of the sole is spaced forward of the forefoot section 16 and underlies at least the middle phalanges MP2-MP5 and distal phalanges DPl - DP5 of the toe of the wearer's foot.
The sole 10 is formed so that an area of reduced support or reduced resistance to downward loading or movement is located in the first region 28 of the forefoot section 16. The first region 28 is formed of a resiliently deformable material that offers less resistance to downward movement than the region surrounding the first region, i.e. the second region 30, and also the toe section region 18. Region 28 may be formed of a material having a lower durometer than the surrounding regions 30 and 18. Preferably, region 28 will have a Shore A hardness in the range of 30-35, which closely matches the hardness of the fat pad of a typical human foot. Alternatively, region 28 may be made thinner so as to at least in part fall below the surface of the second region 30 and toe section 18. Region 28 may be formed as a separate element, e.g. a plug or insert 40 cut or built into the sole 10, or as a recess formed in the top or bottom surface of the sole, e.g. by molding or by machining. Region 28 may be covered by a flexible liner (not shown).
Also, a region within region 28, underlying substantially only the first metatarsal head of the wearer includes a hollow or depression 42, relative to the remainder of region 28, of asymmetric shape, with the lowest point of the hollow or depression skewed to the medial side of center. That is to say, as seen particularly in Fig. IA, the hollow or depression 42 has a shallower slope on its lateral side.
In practice, depression 42 is round or nearly round in plan, and the corresponding medial and lateral walls 44 and 46 are also somewhat rounded or curved. Accordingly, as used herein, "slope" is an imaginary line or cord running between the top edge of the side wall and a point where the side wall morphs into the bottom of the depression. This is best seen by phantom line 43 (Fig. 4) which is an imaginary cross-sectional line through the midpoint of insert 40. This unique geometry has the effect of rotating the first metatarsal head of the wearer into eversion as the wearer moves from midstance to propulsive phase.
In dimensions, the hollow depression 42 should be large enough in plan to accommodate the first metatarsal head, at least in part. In a typical embodiment, depression 42 is substantially circular in plan, preferably having a diameter of about 2.54 cm. to about 3.81 cm., depending on foot size. The depression also may be oval, egg-shaped, or elongated in plan, and should have a nominal depth preferably in the range of about 2-3 mm measured from the top edge of the side walls to the lowest point of the depression. Despite this relatively small amount, this has a profound effect of rotating the first metatarsal head into eversion as the wearer moves from midstance to propulsive phase. In an alternative embodiment, the depression 42A is somewhat elongated and slightly wider at its toward end, e.g. as shown in FIG. 3-4.
The insoles described above may be used with street and sport footwear including sandals. As noted above, the insoles may be incorporated into an insole board at the time of manufacture, formed as a sock liner or as an aftermarket insole device or a custom or prefabricated (over-the-counter) orthotic for placing into a shoe by the wearer.
FIG. 6 is an illustration of a shoe sole 1 10, in accordance with a preferred embodiment of the present disclosure. The orthotic device 1 10 includes a composite insole having a footbed 1 12, a lateral arch region 1 14, a medial arch region 1 16, and a heel region 1 18. The footbed 1 12 and the lateral arch region 1 14 have a first hardness value. The medial arch region 116 has a second hardness value that is softer than the first hardness value. The heel region 1 18 has a third hardness value that is harder than the first hardness value.
In use, the heel region 1 18 underlies the heel of the wearer's foot. Likewise, the lateral arch region 1 14 and the medial arch region 1 16 underlie the arch of the wearer's foot. The footbed 1 12 extends from the central space between the lateral arch region 1 14 and the medial arch region 1 16 to the fore of the orthotic device 1 10, beneath the ball of the wearer's foot, including the first, second, third, fourth, and fifth metatarsals. Varying durometer of the orthotic device 1 10 are selected to approximately match the regions of varying hardness of the underside of the wearer's foot. While foot shapes and size vary significantly from person to person, anthropometric studies show that the hardness of the "fat pad" of the bottom of the average human foot does not vary significantly. Accordingly, we have determined that footwear may be made significantly more comfortable to the average user, and bio-mechanical efficiency improved by varying the hardness of the insole to approximately match the regions of varying hardness of the underside of the wearer's foot. In essence, in the context of the present invention, applicants mechanically impedance match the insole to the underside of the foot so that the amount the insole moves for given force is essentially the same as the movement of the padding of the underside of the foot. In this way, the insole is a natural extension of the padding of the underside of the foot. For example, the first hardness value may be approximately 20 to 60 Shore C, preferably about 40 Shore C, the second hardness value may be approximately 15 to 55 Shore C, preferably about 35 Shore C, and the third hardness value may be approximately 30 to 70 Shore C, preferably about 50 Shore C, where Shore C is a durometer scale recognized by the American Society for Testing and Materials. Under Shore A, another durometer scale recognized by the American Society for Testing and Materials, those preferable values are approximately 20 Shore A, 15 Shore A, and 30 Shore A, respectively.
While the footbed 1 12 and the lateral arch region 1 14 are described as having the first hardness value, these two regions may have slightly different hardness values without departing from the scope of the present disclosure. Rather these regions are described together based upon having approximately similar hardness values relative to the heel region 118 and the medial arch region 1 16.
In a preferred embodiment of the invention, the footbed 112 may also have a depression or hollow 120 located approximately beneath the location of the first metatarsal head of a user's foot, i.e. in accordance with the teachings of my aforesaid U.S. Patent 4,597, 195 or my aforesaid co-pending U.S. Application Serial No.
12/534,741, and as described above with reference to Figs. 1 -5. As described in my aforesaid '741 application, and above, the hollow or depression 120 promotes eversion of the first metatarsal head as the wearer moves from midstance through propulsive phase. This hollow or depression 120 should have the same approximate hardness as footbed 1 12 and the lateral arch region 1 14, though differences may be expected depending on the method of production.
The various regions of the device 1 10 may be manufactured unitarily, may be co-extruded, bonded together, adhesively joined, chemically joined, mechanically joined, or unified in any manner known to those having ordinary skill in the art. The shoe sole device may be used with men's, women's and children's street and sport footwear, including sandals. The shoe sole may be incorporated into an insole board at the time of manufacture, formed as a sock liner, or as an aftermarket insole device or a custom or prefabricated over-the-counter orthotic for placing into a shoe by the wearer. If formed within a sock liner, insole board, or other similar encompassing product, the various regions of the shoe sole 10 may not be joined to each other, but may simply be held in place by the encompassing product.
Various changes can be made in the above construction without departing from the scope of the invention. For example, an asymmetrically shaped hollow having tapered side walls skewed to the medial side of center may be formed extending downwardly from the bottom of an insole board or sock liner of a shoe, and underlying substantially only the first metatarsal head. Also, if desired, a device can be designed with a depression formed essentially half-way through, from side to side, e.g. as illustrated in FIG. 5, so that the device can be turned or flipped over and function as either a right or left shoe part. It is intended therefore that matter contained in the above description or shown in the accompanying drawings shall be interpreted as an illustrative and not in a limiting sense.
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