FOOT-ENGAGING LINER FOR BOOT OR SHOE

Abstract: A foot engaging liner (10) to overlie the outsole of a boot or shoe comprising: a base (11) having a required insole profile to overlie the outsole and defining a toe region (12) and a heel region (13) in which the base has a recessed cradle (19) of deformable material to be located below the ball of the foot of the wearer; and an impact load distribution portion (14) extending transversely to the general axis of the base between the toe and heel regions, said portion being intended to support the metatarsal region of the foot of the wearer.

Description: FOOT-ENGAGING LINER FOR BOOT OR SHOE This invention relates to a foot-engaging liner for a boot or shoe . The invention may be applied to an "insock" of a shoe i.e. a liner which forms part of the assembly of the component parts of the shoe, or may be applied to a removable insole. Both of these examples are therefore intended to be included within the term "foot-engaging liner". The invention has been developed primarily in connection with sports shoes and boots, and in which it is desirable to minimise the application of localised high pressure to the underside of the foot of the wearer, as a result of ground impact. This is achieved, in the case of so-called "trainer" shoes, by providing resilient cushioning in the insole of the shoe, and which acts to redistribute ground impact loads, thereby reducing localised high pressure being applied to the underside of the foot. The "ball" region of the foot (the metatarsal-phalangeal joint of the big toe to the foot) is particularly exposed to impact loads, and the present invention addresses the problem of minimising the impact pressures applied to this region of the foot . According to an aspect of the invention there is provided a foot -engaging liner to overlie an outsole of a boot or shoe and comprising: a base having a required insole profile to overlie the outsole and defining a toe region and a heel region; the base having a recessed cradle of deformable material to be located below the ball of the foot of the wearer; and an impact load distribution portion extending transversely to the general axis of the base between the toe and heel regions, said portion being intended to support the metatarsal region of the foot of the wearer. A liner according to the invention therefore provides yieldable support for the ball of the foot via the recessed cradle, and which allows part of the metatarsal-phalangeal joint (MPJ) to be located above the recess in the cradle, and with the remainder of the joint being supported by the cradle. This allows the big toe to move freely, while the joint is supported via the cradle. Therefore, during running or walking, the big toe can flex easily, while the joint works properly i.e. without restriction, via its support on the cradle . Preferably, the recessed cradle is arranged in a recess in said load distribution portion. Preferably, said recessed cradle and said impact load distribution portion are integral portions of a single raised structure extending generally transversely to the general axis of the base between the toe and the heel regions . Preferably there is an additional layer of material overlying the base to assist in redistribution of excess pressure away from the ball area of the foot. The cradle of the foot engaging portion may be generally U-shaped to define a recess to form a seating for part of the ball area of the foot. The edge of the cradle which defines the recess may be bevelled to mimic the contours of the planar surface of the metatarsal head. It can therefore accommodate varying sizes and lengths of metatarsals, and is situated within the recess in the transversely extended impact load bearing portion which forms effectively a type of "forefoot" bar. The cradle may be made of a closed cell non-deforming rubber. The foot engaging liner may include a further layer of deformable material overlying the base and cradle. This further layer may be made of an open cell material. The foot engaging liner may form the insock of an assembled shoe or take the form of a removable insole. Preferably the recessed cradle is an integral portion of the base . The foot engaging liner may be moulded from EVA foam. There may be a further overlying layer overlying the base and cradle for increasing the resistance to wear of the liner. It may also include a raised instep region for supporting the instep of the wearer. Preferably, the recessed cradle is made from a pad of gel such as silica gel. Under load the gel is pushed out allowing the joint to sit properly and cushioning the joint around its base . The foot engaging liner may have a multipart construction, each part having properties dependent on its function. In a further aspect of the invention there is provided a deformable foot engaging liner for overlying the outsole of a boot or shoe; said liner having an upper surface and a lower surface; an integral portion of the upper surface being a cradle having a recess to be located below the metatarsal-phalangeal joint of the big toe of the wearer; and the recess defining wall of said cradle being shaped for supporting the portion of the foot of the wearer surrounding said joint. The present invention will now be described by way of example only, by reference to the accompanying drawings in which: Figure 1 is a side view, taken from the lateral side, of a foot engaging liner which is intended to overlie an outsole of a boot or shoe; Figure 2 is a side view from the medial side; Figure 3 is a plan view of the liner; Figure 4 is a detail view of a recessed cradle component to be incorporated in the liner, in the metatarsal region thereof ; Figure 5 is a plan view of a second foot engaging liner; Figure 6 is a side view of the second foot engaging liner from the medial side; Figure 7 is a plan view of a third foot engaging liner; and Figure 8 is a plan view of a fourth foot engaging liner. Referring now to the Figures, a foot-engaging liner according to the invention is designated generally by reference 10, and is intended to overlie an outsole (not shown) of a boot or shoe, and especially of a sports boot or shoe. The liner 10 can take the form of an "insock" of a shoe, i.e. to form part of the assembly of the component parts of the shoe, or can take the form of a removable insole. The liner 10 comprises a board 11, having a required insole profile to overlie the outsole, and defining a toe region 12 and a heel region 13. Preferably, the board 11 comprises a so-called Texon type board, known for use in boots and shoes . An impact-load distribution portion is built-into the board 11, and extends transversely of the general axis of the board 11 which extends between the toe region 12 and the heel region 13. This portion is designated generally by reference 14, and is intended to support the metatarsal region of the foot of the wearer. This portion 14 is strengthened, relative to the remainder of the board 11, by providing an additional layer of board material 15, which overlies the board 11, and effectively forms a forefoot bar located below the metatarsal region of the foot i.e. the joint region at which the bones of the toes are connected to the main body of the foot . The additional board layer 15 extends transversely of the general axis of the board 11, from the lateral side 16 towards the medial side 17, but stops short of the medial side 17 so as to define a recess 18. The recess 18 is located below the "ball" of the foot of the wearer i.e. below the metatarsal- phalangeal joint (MPJ) . A recessed cradle 19 (shown in dotted outline in Figure 3) and in detail in Figure 4, is arranged in the recess 18 so as to be below the MPJ. The cradle 19 is generally U-shaped, and is made of suitable deformable material. The preferred material is a closed cell non-deforming type of rubber. The parallel limbs of the U-shaped cradle 19 define a recess 20, and which defines a hollow into which part of the ball of the foot can be seated, while the remainder of the joint is supported on the base and parallel limbs of the U- shaped cradle 19. This allows the ball of the foot (the so- called first MPJ) , to work properly, while allowing the big toe to move freely, and in a correct bio-mechanical manner. To improve the seating of the joint on the cradle 19, preferably the edge region of the cradle 19 which defines the recess 20 is bevelled, to be a suitable receptacle for the metatarsal head. This permits accommodation to varying sizes and lengths of metatarsals, and, by being located within the forefoot bar structure formed by the load distribution portion 14, 15, this redistributes excessive pressure away from the first MPJ area. In order to reduce shearing forces and the resultant skin lesions normally associated therewith, the cradle 19 and the whole of the forefoot is covered with a layer 21 of deformable material, which is an open cell material. The cradle 19 can be situated in the insock of a shoe, or in a removable insole, which can be sold separately, and be included in the shoe package for purchase by customers . A particular advantage of the metatarsal cradle/insole structure disclosed herein is : i. to allow plantarflexion of the first metatarsal head during the propulsive period of gait, so as to allow functional movement of the first proximal phalange on the first metatarsal head, thereby reducing pathological compressive forces at the metatarsal - phalangeal joint. ii. The location of the stud/receptacle does not allow the first ray/metatarsal head to plantarflex, but the addition of the metatarsal cradle increases the ability of the first ray to plantarflex and hence increases the mechanical efficiency of the forefoot . A further embodiment of the invention is shown in Figures 5 and 6. The liner 10 is comprised of a single moulded piece of compressible EVA foam, shaped to overlie the outsole. An integrally moulded portion of the liner comprises a generally U-shaped recessed cradle 19. The recess defining walls of this cradle are shaped to support the portion of the foot surrounding the first metatarsal-phalangeal joint of the wearer. An integrally moulded impact load distribution portion 25 of the liner 10 extends transversely to the general axis of the base between tow and heel regions. This portion is suitable for supporting the metatarsal region of the foot of the wearer, the recessed cradle is located within a recess in the impact load distribution portion. The liner 10 also comprises a raised instep portion 22 and a heal depression 23 for supporting the instep and heel of the wearer respectively. The liner also comprises a raised rim 24. The rim 24, in combination with the instep portion 22 prevents lateral displacement of the foot of the wearer relative to the liner when the liner is in use. This prevents wear on the liner and skin lesions on the foot of the wearer. Bonded to the upper surface of the liner is a rubber / fabric composite material. This composite material strengthens the lining and also improves its resistance to friction wear. It also reduces the friction experienced by the sole of the foot of the wearer. Extending through the liner 10 are a number of holes 25 for allowing moisture to escape. Shown in Figure 7 is a third embodiment of the invention. The impact load distribution portion and recessed cradle form integral portions of a single raised structure extending generally transversely to the general axis of the base between the toe and heel regions. Shown in Figure 8 is a fourth embodiment of the invention.

Claims: CLAIMS 1. A foot engaging liner to overlie the outsole of a boot or shoe comprising: a base having a required insole profile to overlie the outsole and defining a toe region and a heel region; the base having a recessed cradle of deformable material to be located below the ball of the foot of the wearer; and an impact load distribution portion extending transversely to the general axis of the base between the toe and heel regions, said portion being intended to support the metatarsal region of the foot of the wearer. 2. A foot engaging liner as claimed in claim 1, wherein said recessed cradle is arranged in a recess in said load distribution portion. 3. A foot engaging liner as claimed in claim 1, wherein said recessed cradle and said impact load distribution portion are integral portions of a single raised structure extending generally transversely to the general axis of the base between the toe and heel regions. 4. A foot engaging liner as claimed in any one of claims 1 to 3 , further comprising an additional layer of material overlying the base to assist in re-distribution of excess pressure away from the ball area of the foot. 5. A foot engaging liner as claimed in any one of claims 1 to 4, in which the cradle is generally U-shaped, to define a recess to form a seating for part of the ball area of the foot . 6. A foot engaging liner as claimed in claim 5, in which the edge of the cradle which defines said recess is bevelled to mimic the contours of the planar surface of the metatarsal head. 7. A foot engaging liner as claimed in any one of claims 1 to 6 , in which the cradle is made of closed cell non- deforming rubber. 8. A foot engaging liner as claimed in any one of claims 1 to 7, including a further layer of deformable material overlying the base and cradle . 9. A foot engaging liner as claimed in claim 8, in which the further layer is made of an open cell material. 10. A foot engaging liner according to any one of the preceding claims, in which the liner forms the insock of an assembled shoe or takes the form of a removable insole. 11. A foot engaging liner to overlie the outsole of a boot or shoe as claimed in either of claims 1 or 2, said recessed cradle being an integral portion of said base . 12. A foot engaging liner as claimed in claim 11 and moulded from EVA foam. 13. A foot engaging liner as claimed in either of claims 11 or 12, further comprising an overlying layer overlying said base and cradle for increasing the resistance to wear of said liner. 14. A foot engaging liner as claimed in any one of claims 11 to 13, further comprising a raised instep region for supporting the instep of the wearer. 15. A deformable foot engaging liner for overlying the outsole of a boot or shoe; said liner having an upper surface and a lower surface; an integral portion of the upper surface being a cradle having a recess to be located below the metatarsal-phalangeal joint of the big toe of the wearer; and the recess defining wall of said cradle being shaped for supporting the portion of the foot of the wearer surrounding said joint.

Inventors: LYONS STEVEN, LYONS, STEVEN
Applicants: LYONS STEVEN, UMBRO EUROP LIMITED, LYONS, STEVEN, UMBRO EUROPE LIMITED
Application year: 1997
Main classification: A43B7
IPC codes: A43B7, A43B13, A43B17