Applicant: Hallufix AG F/LE/ E Our ref. : H83741 PCT

Corrective Insole for Treating Defective Positioning in the Metatarsal and Forefoot Area

The invention relates to a corrective insole for treating defective positioning in the metatarsal and forefoot areas in accordance with the preamble to claim 1 . Such defective positioning, such as for instance Hallux Valgus, hammer toes, or claw toes, sometimes occurs due to hereditary abnormalities and sometimes due to faulty footwear or overloading or malpositioning of the lower extremities. The following explanations are limited for the purpose of providing an example of widespread malpositioning known as Hallux Valgus, but they also apply in like manner to other types of defective positioning in the metatarsal and forefoot area. Hallux Valgus is defined as an outward deviation of the big toe at the metatarsophalangeal joint. "Outward" here and in the following always indicates a direction away from the center plane of the body; in this case, then, towards the small toe. Consequently, "inward" is the opposite direction, that is, from the small toe towards the big toe. In Hallux Valgus, the tendons for the toes no longer run centrally across the joint, but rather run further inward, and they pull the toes into a slanted position. The ball of the big toe, which projects because of this, frequently suffers painful inflammation, caused by the pressure of the shoe in this area. At the same time, the angle between the various metatarsal bones is enlarged, especially between the metatarsal bone adjacent to the big toe and the proximal phalanx of the big toe. A frequent accompanying symptom is arthrosis. Among the causes of Hallux Valgus are splay foot, with the anterior transversal arch caving in and the big toe deviating as a result, and especially faulty footwear, which, due to fashion, is frequently worn in a size that is too small, has heels that are too high, or has a toe area that is too narrow.

In addition to surgical treatment, orthopedic measures such as special splints or corrective insoles are customary for correcting Hallux Valgus. One such corrective insole is known from DE 20 2004 006 1 13 U 1 . This publication describes an insole that in the area of the toes has an elastic strap that is guided through a slit in the sole. This strap can be stretched about the big toe such that it brings it into a position required for correcting Hallux Valgus.

In the known corrective insole it is disadvantageous that it only effects incomplete correction of the defective positioning because it affects only the position of the big toe itself. This is not suffi- cient for effective and lasting correction of the defective positioning, however, because there is no change in the angular position of the metatarsal bones.

The underlying object of the present invention is therefore to create a corrective insole of the aforesaid type by means of which it is possible to attain improved and comprehensive correc- tion of the underlying defective positioning of all of the foot bones involved.

Note: Here and in the following, the term "corrective insole" is always used for the complete arrangement made of an "insole" in the conventional sense and the strap mechanisms attached thereto. "Insole" then refers only to the sole without any additional components.

This object is attained in accordance with the characterizing portion of claim 1 in that another stretchable strap mechanism is arranged guided via openings in the insole.

The invention is based on the understanding that to completely correct the defective positioning, especially for Hallux Valgus, the angular position must be changed and maintained not only for the big toe, but also for the metatarsal bones adjacent thereto. This occurs in accordance with the invention in that an adjustable, correcting force is exerted on the metatarsal bones in the center area of the corrective insole using another stretchable and fixable strap mechanism, especially in the area above which the metatarsal bones are positioned when it is worn. This force, together with the force exerted on the big toe by the strap mechanism in the toe area, effects an optimum change in the angular position of the bones involved in that it pivots the big toe inward and pivots the associated metatarsal bones outward. This converts the incorrect positioning of the two adjacent bones relative to one another to a correct, aligned orientation. Particularly advantageous is the preferred step-less adjustment of each strap mechanism, for instance by means of a Velcro fastener, which permits the force, and thus the angular position of the body parts involved, to be finely adjusted. In accordance with the invention, the position of the big toe and its bones and the position of the metatarsal bones can be adjusted separately because the two strap mechanisms can be actuated independently of one another.

Another advantageous embodiment of the corrective insole can be comprised in that in accordance with claim 2 the additional strap mechanism is arranged such that when the corrective insole is worn the foot is in contact with the strap of the strap mechanism not only on the back of the foot and at the sides but also in that parts of the sole of the foot are also encircled. This avoids the foot being pressed flat onto the insole, which would act against correcting the Hallux Valgus because the metatarsal bones are spread even more by this. Instead, the inventive encirclement of the metatarsal area ensures that these bones in this area are subjected to a force in the center in the sense of bundling. Thus, this area of the foot is more rounded than flattened by the force of the strap. This effect is attained in accordance with the invention in that the strap of the additional strap mechanism is conducted via longitudinal openings that are disposed essentially parallel to one another at the same longitudinal position of the insole and that are clearly offset to the center relative to the adjacent lateral edge of the insole. They thus come to be disposed beneath the sole of the foot when the corrective insole is worn so that the associated strap encircles the foot for the most part.

In accordance with additional advantageous embodiments, there can be three openings associated with each strap that are arranged parallel to one another, at least with respect to their longitudinal extension. One end of the strap is conducted through an opening; preferably the opening located on the outside of the insole, and is fixed to the bottom of the insole. This can occur using an appropriate embodiment of the end, for instance a thickening that engages in a positive fit and/or non-positive fit with the opening, which is specially shaped for this purpose, when the strap is threaded through from the bottom. Naturally this end could also be securely or detachably connected to the insole by other means or measures. It would be possible to use rivets or adhesive or a Velcro fastener. The free end of the strap is conducted through a second opening, forming a loop for the foot, and this second opening must also be disposed beneath the sole of the foot. The strap runs from here beneath the insole to the third opening, through which it exits upward and at its free end can be gripped, stretched, and fixed on the top of the foot. In accordance with the invention, a Velcro fastener is preferably used for fixing it when it is stretched because such a fastener can be displaced and fixed in a stepless manner. Naturally other types of fixation are also possible, such as for instance buckles, ratchetlike fasteners, or snaps.

In one modification of the invention, an embodiment having only two openings for the strap is provided. The free end of the strap is not conducted through a third opening as in the first ex- emplary embodiment of the invention. Instead, after passing through the second opening, it is conducted upward from the bottom of the insole around the adjacent outer edge and is fixed there after stretching.

Also included in the framework of the invention is a design for the corrective insole in which the strapping in the toe area of the insole has a plurality of strap mechanisms or more than three openings for guiding one or a plurality of straps. This makes it possible to exert a corrective force not only on the big toe, for improving Hallux Valgus, for instance, but also to include other toes, as can be necessary for instance in treating hammer toes or claw toes. The openings in the insole are distributed for this purpose across the width of the toe area and can be fitted with strap mechanisms depending on the requirements for the correction needed. Here and in the rest of the description, strap mechanism always means a stretchable strap having one fixed secure end and one fixable and detachable free end that has at least one loop for a part of the body to pass through, for instance the metatarsal area of the foot or a toe, and that is conducted via the associated openings in the insole. The insole preferably has areas of different hardness such that it is embodied harder and more stable in the area of the openings and of each strap mechanism than in the other areas. This ensures that the insole is sufficiently stable in the area of the strap mechanisms to absorb the forces necessary for correcting the defective positioning. In addition, the insole should be soft and flexible as desired in the other areas. Thus the flexibility in the longitudinal direction of the insole that is necessary for the foot to roll when walking is attained such that a relatively soft and flexible area is arranged between the metatarsal area and the forefoot/toe area. This intermediate area and a heel area of the insole that is embodied correspondingly soft are also necessary for wearing comfort.

Preferably plastic is employed as the material for the inventive corrective insole, because it is particularly suitable for cost-effective production using injection molding and is available in numerous modified forms, such as solid or foamed material. Different types of materials can be combined for the different areas of the insole, or different modifications of a material, such as more or less foam, can be arranged adjacent to one another. In addition to pure plastics, such as for instance polyurethane or ethylene vinyl acetate (EVA), it is also possible to have combi- nations with other materials such as cork, leather, and metal inlays. The mechanical properties of the insole can be predetermined as desired in this manner with respect to stability, flexibility, and wearing comfort.

In another preferred embodiment, an orthotic sole, that is, a sole with a special shape for the foot bed that when worn effects therapeutic action on the foot, is used for the insole. Particu- larly preferred is a proprioceptive orthotic sole, such a sole being understood to have a stimulating effect on certain nerves or nerve centers due to a special arrangement and shape of elements worked into the foot bed. This causes signals to be produced in the brain that lead to beneficial reactions in the muscular system of the apparatus of locomotion, these reactions acting like therapy for underlying defective positioning in the apparatus of locomotion. Details can be found for instance at the www.podoorthesioloqie.de Internet site. One such insole is particularly effective in supporting the function of the corrective insole.

The inventive corrective insole is used in that the foot to be corrected is inserted into the loops of the corrective insole that are provided for this purpose and then the straps are stretched by pulling their free ends and then the straps are fixed, by means of the fastener, in the desired position, i.e. the position necessary for the correction. This happens outside of the shoe for which the corrective sole is provided. Only once the two straps in the inventive strap mechanism have been adjusted is the foot, together with the corrective insole, inserted into the shoe, which is then laced or held on the foot in some other manner determined by its design. The invention shall be described in greater detail using exemplary embodiments that are illustrated in the figures.

Fig. 1 depicts a corrective insole in accordance with the invention; Fig. 2 depicts another exemplary embodiment of a corrective insole;

Fig. 3 is an elevation of a human foot with a corrective insole in accordance with the invention; Figs. 4a and 4b depict a cross-section through the metatarsal area with the corrective insole positioned thereon;

Figs. 5a and 5b depict a cross-section through the toe area with the corrective insole positioned thereon.

Fig. 6a depicts a further embodiment of a corrective insole in accordance with the invention showing preferred means for reversing the strap.

Fig. 6b depicts a cross section through the metatarsal area of the insole showing preferred means for reversing the strap.

Fig. 6c depicts a longitudinal view of the corrective insole showing preferred means for reversing arranged in the strap.

Fig. 1 is a schematic depiction of a corrective insole 1 in accordance with the invention. It includes the insole 2, which has a foot bed 3 that is preferably configured according to orthopedic principles. The insole 2 is divided into a front toe area 4, a metatarsal area 5, and a heel or rear foot area 6, which merge seamlessly into one another and which are defined by the anat- omy of the foot. The insole 2 has an outer edge 7 and an inner edge 8, "inner" and "outer" being defined as is normal with respect to the center body plane, and it has a bottom 9.

In accordance with the invention, the insole 2 is fitted with at least two separate strap mechanisms 10, the toe strap 11 and the metatarsal strap 2, their designations resulting from their respective positions on the foot bed 3. For receiving, conducting, and fixing each of the straps 1 1 , 12, the insole 2 is provided with a plurality of longitudinal openings 20, 21 , 22, 23 that are conducted from the foot bed 3 through the entire thickness of the insole to its bottom. The shape of the openings 20, 21 , 22, 23 is adapted to the thickness and width of the straps 1 1 , 12 in the strap mechanisms 10, the longitudinal extension of the openings 20, 21 , 22, 23 normally coinciding at least approximately with the longitudinal extension of the insole 2. However, it is also possible to have deviations from this for special corrections, and these are within the framework of the invention.

Each strap, the toe strap 1 1 and the metatarsal strap 12, referred to hereinafter only as "strap" because the embodiments are the same for the two straps, has a free end 13 on which a fastener is arranged that makes it possible to fix the strap 1 1 , 12, after stretching, about the respective area of the foot. This fastener is depicted in Fig. 1 as a Velcro fastener 14, which is preferred for this application because it enables stepless and secure fixation of the strap. The other end area 15 of each of the straps 1 1 , 12 is conducted from below through a first opening 20 in the insole 2 and fixed in or in the vicinity of this opening 20, as shall be explained. The strap is conducted out from here, forming a loop 17 for the foot to pass through above the foot bed 3, and again passes into the insole 2 through a second opening 21. The strap 1 1 , 12 is reversed behind the second opening 21 on the bottom 9 of the insole 2 and passes therethrough from below through a third opening 22. The end 3 of the strap 11 , 12, still free, is thus disposed on the top of the insole 2 and can be grasped from there in order to effect the stretching and subsequent fixation necessary for the correction.

In accordance with the invention, the first and second openings 20 and 21 in the metatarsal area 5 are clearly arranged at a distance from the adjacent edges, outer edge 7 and inner edge 8, of the insole 2, as can be seen more clearly in Figs. 4a and 4b. These distances should be at least 10% of the width of the insole 2 in the metatarsal area, a figure in the range of 15% to 45% of this width being preferred. What this attains is that the metatarsal area of the foot 26 (see Figs. 4a and 4b) experiences a force that acts essentially radially inward, because this area is almost completely enclosed by the metatarsal strap 12. The force oriented in this manner is essential for correcting the defective positioning of the metatarsal bones, because the force bundles them instead of pressing them apart as a strapping engaging only on the lateral edges 7, 8 of the insole 2 would do.

Fig. 2 depicts a modified embodiment of the invention in which the insole 2 has only two openings 20 and 21 for the associated strap 11 , 12. After exiting through the second opening 21 on the bottom 9 of the insole 2, the free end of the strap 1 1 or 12 is reversed along the bottom and encloses the adjacent edge of the insole 2, here the inner edge 8, before it reaches the top of the corrective insole 1 . The other details coincide with the exemplary embodiment in accordance with Fig. 1 , the description of which should be referred to in order to avoid repetition.

Fig. 3 depicts a corrective insole 1 in accordance with the invention arranged on a human foot 26. The foot 26 is inserted with the applied and correctly stretched and fixed corrective insole 1 into the shoe (not shown), which can then be laced in the usual fashion.

Figs. 4a, b are schematic cross-sections of the metatarsal area of a human foot 26 with an applied and stretched corrective insole 2, specifically in accordance with the exemplary embodiment in accordance with Fig. 1 in Fig 4b and in accordance with Fig. 2 in Fig. 4a. The refer- ence numbers here have the same meaning as in the other figures. In particular in Fig. 4b can be seen the three openings 20, 21 , and 22 and how the metatarsal strap 12 is conducted from the first opening 20 as a loop 17 about the metatarsal area of the foot to the second opening 21 and from there through the third opening 22 to the top of the insole 2. For the purpose of clarification, the Velcro fastener 14 on the free end 13 of the metatarsal area 12 is shown not yet fixed. The secure end of the metatarsal strap 12 has a thickening 16 on its outermost end area 15 that fixes this end in the associated first opening 20, since this opening 20 is embodied too narrow for the thickening 16 to pass through. Such fixing of the one strap end to the insole 2 using a positive fit and/or non-positive fit is naturally also possible using other means, such as for instance gluing to the insole 2, by means of a Velcro fastener, or using rivets. Fig. 4a depicts the other embodiment of the corrective insole 1 , having only two openings 20 and 21 in the insole 2 for the metatarsal strap 12 to pass through. In this variant, this free end 13 is conducted about the inner edge 8 of the insole 2 and then is fixed on the top by mean of the Velcro fastener 14.

Figs. 5a, b provide a schematic depiction of a cross-section through the toe area of the human foot with applied corrective insole 1 , a strap mechanism 10 having a toe strap 1 1 being present only in the area of the big toe 28. The toe band 1 1 is conducted completely like that for the metatarsal area in Figs. 4a and 4b, with the single difference that the one secure end of the toe strap here is fastened by means of adhesive 30, indicated here, or a Velcro fastener, to the bottom 9 of the insole 2. It is understood that in accordance with the invention even more open- ings 23 for strap mechanisms 10, 1 1 can be present in the area of the other toes 27 so that these toes 27 can also be subjected to a corrective displacement, individually or in groups

Figs. 6a, 6b and 6c depict a further embodiment of a corrective insole 1 according to the inven- tion, in which preferred means for reversing the straps 1 1 or 12 are shown. When the straps again are passing through the orthopedic insole 2 - after building a loop 17 for the foot or the toe(s) to pass through this loop 17 - the strap is wound around a reversing-roller 31 arranged on the insole, in order to facilitate reversing of the strap when the strap is stretched about the respective area of the foot. After passing the reversing-roller 31 the end 3 of strap 11 or 12, still free, can be fixed, e.g. with the male or female part of Velcro fastener 14. The aforementioned kind of fixing is described by the way of example only for the metatarsal strap 12, but analogously is valid as well for the toe-strap 1 1 .

Instead of a reversing-roller 31 every friction reducing means between the strap material and the sole-material can be used, in order to avoid undesired sticking of the strap 1 1 or 12 on the orthopedic insole 2.

Legend

1 Corrective insole

2 Orthopedic insole

3 Foot bed

4 Toe area

5 Metatarsal area

6 Heel area/rear foot area

7 Outer edge

8 Inner edge

9 Bottom

10 Strap mechanism

1 1 Toe strap

12 Metatarsal strap

13 Free end

14 Velcro fastener

15 End area

16 Thickening

17 Loop

20 First opening

21 Second opening Third opening Openings Foot

Toes

Big toe

Metatarsal bones Adhesive Reversing-roller