US2640282A - Foot-arch support structure - Google Patents

Description

June 2, 1953 w. WISBRUN FOOT-ARCH SUPPORT STRUCTURE Filed April 4, 1950 INVENTOIIQ. WflLTEA l VlJb P By r .4 TTDEIYE Y5 TALUS OR ASTRAGALUS CALCANEUS Patented June 2, 1953 UNITED STATES PATENT OFFICE ,7 .2540282 h... FQOT-ARCH SUPPORT STRUCTURE alter Wisbrun,-'Cleveland Heights, Ohio I 7 Application April 4, 1950, Serial- No;j-153,789"f 4Claims. (c1. 36s.-.5): I

Extended study of the internal mechanics of the foot shows that an arch support of the common: form .does not fully cover the physiological requirements. These requirements are: (1) To provide a corrective effect upon the deformed skeletalstructure and to restore muscular equ1- related ends, said invention then comprises the featureshereinafter fully describedand particularlyupointed out in the claims, the following description and the annexeddrawing setting forth in 'detail certain illustrative embodiments of the invention,:these being indicative, however, of but azfewof the various ways in which the principle of the inventionmay be employed. In said: annexed drawing;

. Fig. :1 is a sideelevational view of the skeletal structure-of the foot as by X-ray; 1 r

1. Fig.-.2'is a plan View, as by X-ray, corresponding to Fig. 1, but with the" terminal phalanges omittedJ- I .Fig. 3 is an elevational view of the inner side of ashoe embodying the invention; 7

Fig.4 is .a vertical section thereof taken on plane substantially indicated by lineIV, Fig. 3; -Fig.. 551s a similar view of a modification; and

Fig-,6 is a plan'view of a rear section blank which. may be used for the assembly of the shoeuppenq. v, w

;A.-i:brief consideration of the anatomy and physiology of the structure of the foot will assist inz'ans'understanding :of the principles involvedin the fpresentdnvention: i

--In.;the normal function of the foot skeleton in walking. an .automatic .alternation of the tarsal joints" is involved cbetw'een supination inthe swinging phase; and pronation in the propellingi phase: Thisf'rhythmical motion is carried out betweenlthe sub-talar 'foot plate on the one hand, R

and the-leg and the talus on the other; The subtalar foot plate i suspended on the talus on two coordinated rotary joints, the talo-navicular ball and socket'joint, and the pivot joint between the sustentaculum-tali and the-corresponding groove oi tlfe iiifeid medial aspect of the collum tall.

- the foot; in other words, brings the great toe in contact with'theiground, which concludes the stance phase by repelling the foot from the ground", This rotary motion of the foot is trans: mitted through the leg and the entire body, creating; wcentrifugal power, which" substitutes and economizes the expenditure of muscle power.

- .Ihecuboidoccupies a: keystone position in the skeletal structure of-the foot. It is thelateral portion of the so-called tarsal arch, a rigid structur rcomposed of five tarsal bones, which rotates about .thetalo-navicular joint; and furthermore, strong connecting ligaments'pull the anterior end ofv the calcaneus behind the cuboid rotating inferiorly in supination and superiorly in pronation..- In standing, the: cuboid is elevated in the normallfoot, and in walking it rotates downward. intheswinging phase and upward in the stance phase. This mechanism gradually deteriorates inflat-fo'otthe cuboid in conjunction with the anterior. end of the calcaneus sags, and finally a li-ftingof .the cuboid andthe anterior end of the calcaneus .in'the stance phase fails to occur,-and the typical weary and un-elastic flat-foot gait develops Shoemanufacturers have attemptedtOnlltiliZS the keystone position of the cuboid by specifically building a cuboid support into the shoe. =.This however, proves wholly inefiectiva;

because. concentrated pressure in sucha small area cannot be tolerated. Further attempts in the 'directionof extending the under-neathsupport -further in -a-lon'gitud1naldirection on the shoesole stilldid not eliminate the-shortcomings inherent in-foot supports as far as they actually provide supportingcounter-pressure. It did not fulfillthe expectation of eliminating the dead space between'the foot at the'instep and the shoe. Ihave found that the reason for this; shortcoming was that such a support was of an areato'equal the entire plantar fascia and the anterior and posterior foot. cushions. A detailed study of the plantar portion of the foot shows that the plantar fascia really covers three longitudinal sections of the arch, there being septa or fascious' tissue extending from the plantar fascia to the skeletal portions abovath'us divid- "A it ing off three general compartments, an inner, a central, and a lateral, and in these compartments there are respective muscle groups extending generally fore and aft connected to the respectively adjacent portions of the skeletal system. The central muscle group is comparatively weak but the central portion of the plantar fascia is 3 to 4 mm. thick and runs sagittally from the under surface of the calcaneus to the plantar parts of the metatarso-phalangeal joints, while the medial and the lateral portions of the plantar fascia run transversely, joining on the dorsum of the foot. The central portion of the foot skeleton comprises the main weight-bearing part of the foot, the lin of gravity and the axis of rotation of the talo-navicular joint crossing each other at the interval between the second and third metatarsal heads. The medial muscle group is the strongest, and the first metatarsal bone in conjunction with the medial cuneiform and the navicular has the greatest mobility of the three portions. The previously-mentioned up and downward motion of the cuboid about the talo-navicular ball and socket joint is joined by the first metatarsal bone. And conversely, the cuboid move downward when the first metatarsal bone is rotated upward, and vice versa. The lateral portion or section of the foot structure takes the least part in supporting the body. The fourth and fifth metatarsals are movably connected with the cuboid, and their function is mainly to adapt the weight-bearing surface of the foot to uneven ground. For this purpose they are provided with a very strong muscle mantle. This tri-partite structure and function of the foot has heretofore not been taken account of in arch supports, but it should be. An important concept in the present invention is that an arch support which merely provides contact or counter-pressure on the under-surface of the foot skeleton is ineffective, and harmful by causing either periosteal irritation or pressure-atrophy of the muscle lying between the appliance and the bones, or both; and the present invention designs to strengthen or to restore respectively, the bracing effect, in the first place of the central portion of the plantar fascia. A medial extension of bracing or sling support to cover the medial portion of the plantar fascia up the inner surface of the instep is provided to support the talc-navicular articulation upon which the rhythmical play of the calcaneo-cuboid junction is centered. This is achieved by in effect restoring the bracing or sling effect of the plantar aponeurosis in this region. On the other hand the inferior bracing element adapted to the central and lateral portions of the plantar aponeurosis is kept on the order of a half inch distance from any bone surface. The pressure thus distributed over the entire extent of the medialand lateral muscle compartments restores the turgor of these muscle groups, or turns them in effect into hydraulic cushions, the upward and inward counter-pressure restoring the muscle equilibrium and the normal posture of the foot skeleton. By distributing the pressure over such a large surface, no concentrated points of irritation can result.

Flat-foot bone positions are shown in full lines in Fig. l, and the normal by dotted lines N.

From the relationships in the bony structure, it is seen that the weight exerted through the leg is applied at a line of center of gravity c--c, Fig. 3, this lying in the middle muscle compartment.

And the line of rotary motion d, Fig. '3, at the talo-navicular joint converges to this line in the interval between the second and third metatarsal heads. The supporting pressure upon one foot must equal half of the weight of the entire body, and at times the whole weight, and this amount of pressure if concentrated upon one spot would be intolerable. By the provision of an extensive pliant support element or sling along the inner side of the instep the pressure is evenly distributed in accordance with the requirements of the support in a vertical direction and the counteraction of the inward roll or turn due to abduction in fiat-foot.

The medial section of the foot participates only secondarily in the sagging of the foot, since the talus i seated on top of the calcaneus. For this reason it does not particularly need support by upward counter-pressure, because the sag of the talo-navicular joint is compensated by the lifting of the calcaneo-cuboid junction. The talonavicular junction moves to the medial side in fiat-foot, because lengthening of the foot is prevented by the traction of the central portion of the plantar fascia. The result is that the forefoot is abducted and that the ligaments of the medial capsule (the tensile strength of which is considerable in a longitudinal direction but much smaller transversely) are expanded transversely and yield more and more to the abduction of the forefoot. The medial capsule or portion at the inner side of the foot therefore is reinforced in. the present invention by a pliant brace or sling which tightly encompasses the medial or inner side of the foot. Since the medial capsular ligaments are inserted at the under surface of the skeletal structure, the proper effect can only be obtained when actually the medial and part of the inferior surfaces of the arch are closely and continuously embraced. This purpose can only be achieved when there is supplied a close, pliant but firm support or sling against the medial or inner surface of the foot in effect in continuity with the rigid support of the central and lateral or outer portions of the plantar aponeurosis. Such an effect cannot be obtained either by a rigid pressure element on the medial side of the foot, or by merely taking in the medial part of the shoe-upper and narrowing the shank of the shoe. In the first case, pressure-atrophy of the crucial medial muscle portion would develop, as above pointed out. And in the second case, the greatest and most significant part of the dead space between the foot and the sole of the shoe would still remain. I therefore provide an elevated platform 2, Fig. 3 of the drawing, on the sole of a shoe, built in, this platform being in the sub-arch portion with respect to the foot, and sloping fore and aft at and a, to the ball and heel respectively. This platform is relatively firm, as distinguished from a cushion, and may be made of any suitable material, to give a build up particularly for the central outer and central portions of the tri-partite structure of the foot. Thus, the platform is recessed or cut in at its intermediate zone 1', and the extent to which it is thus recessed or narrowed at such intermediate portion may correspondingly be less than about 70 per cent of its width at maximum point, or in general -75 per cent. Joined to the recessed edge of the elevated platform 2, and in effect forming a continuation directed upwardly, but pliant instead of with the firmness of the said platform, is a support element 4, Fig. 4, which for convenience of manufacture may in some cases be a shoe upper or vamp element forming the portion which contact the instep or inner surface of the ankle between heel and ball of the foot. This element 4 is in effect a pliant sling which is secured below to the edge of the elevated platform 2 and thence extends upwardly to the top of the shoe. It is to be noticed that unlike an ordinary shoe-upper outline, the member 4 is strongly narrowed inwardly to engage against the foot, the leather or cloth blanks of which the shoe upper is assembled, being cut to a shape that when seamed together, the seam, as at 5, Fig. 3, draws closely in and narrows the space at such zone. Thus, as indicated generally at Fig. 6, the blank or the rear section 6 may have its forward edge 1 shaped so that when seamed with the co-acting edge portions 8 of the adjacent blank edges, there is a pronounced drawing in or narrowing. As the Wearers foot is then inserted in such an article of footwear, the outer surface of the foot is against the outer portion 9 of the upper, the base of the foot at the arch is supported by the platform 2, and the inner surface from thence upto the top of the shoe is supported by the strongly indented portion 4 of the shoe-upper, and the latter provides a pliant although firm support or sling against tendency to inward roll, while the base of the foot at the instep is supported by the relatively rigid platform 2. A support thus complete is afforded for the entire section of the foot between the ball B and the heel H of the shoe.

In some cases, instead of having the shoe upper per se constitute the sling or support element for the inner side of the instep, the support element 4', Fig. 5, can be generally shaped along the lines as foregoing, and likewise pliant, as of leather or fabric, be secured to the recessed edge of the platform support 2 below, and be secured. to the top edge of the shoe-upper u, which latter may be of the usual external contour. In such case, there is a dead space between the shoe upper and the sling or support 4', but the latter snugly bears against the foot, and the dead space outside is of no moment insofar as the foot is concerned. This form of construction shows externally as the customary contour of a shoe, while the form in Fig. 4 shows externally a more deeply recessed contour.

Where high shoes, or boots, are to be equipped with the built-in support construction, the sling element need not be carried higher than the equivalent of the top of the low style or Oxford shoe. The feature in any case is the providing of a pliant snugly engaging support up along the whole of the inner surface of the instep and in continuity from an elevated support-platform under the sub-arch. i

Withal, a complete buttress is provided at the instep, in general L-shape curvate form with base as a platform relatively firm and with inner edge recessed, and the upwardly directed limb longer and more pliant.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims or the equivalent of such be employed.

I therefore particularly point out and distinctly claim as my invention:

1. In footwear having a firm sub-arch support element secured above the shoe sole, said support being recessed toward the mid-line of the shoe at its inner edge, an extension support element therewith in pliant sheet form connected to the inner edge of said firm sub-arch support and extending up to anchorage all along its upper edge on a line at low shoe top level.

2. In footwear, a low shoe including a sub-arch firm support secured to the shoe sole, said support being recessed toward the mid-line of the shoe at its inner edge, and a support extension therefrom in pliant sheet form having its lower edge anchored along the inner edge of said firm support and its top edge anchored all along the shoe top-edge.

3. Footwear, having a pliant sling support with continuous anchorage all along the top edge of a low shoe upper and extending down along the inner side of the shank, and an elevated platform secured to the sole under the arch, said platform being recessed toward the mid-line of the shoe at its inner edge, to which edge such pliant sling is fastened.

4. A built-in foot arch support in footwear, comprising a buttress elevation secured to the sole, said buttress elevation being recessed toward the mid-line of the shoe at its inner edge, and a support surface continuing up from the inner edge of said buttress at the inner side of the arch to an upper substantially horizontal line of anchorage at the level of a low shoe top edge.

WALTER WISBRUN.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,276,603 Wilms Aug. 20, 1918 1,447,463 Cooper Mar. 6, 1923 1,495,107 Reed May 20, 1924 1,634,816 Allen July 5, 1927 1,833,628 Woodruff Nov. 24, 1931 1,959,247 Minor May 15, 1934 2,070,116 Cutillo Feb. 9, 1937. 2,188,182 Gould Jan. 23, 1940 FOREIGN PATENTS Number Country Date 11,329 Great Britain June 22, 1916 213,085 Great Britain Mar. 27, 1924 336,807 Great Britain Oct. 23, 1930

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