US3545447A - Heel stabilizer - Google Patents

Description

United States Patent Jack .I. Silverman [72] Inventor 15 Cypress Road, Eastchester, New York 10709 [21] App1.No. 745,531 [22] Filed July 17, 1968 [45] Patented Dec. 8, 1970 [54] HEEL STABILIZER 7 Claims, 10 Drawing Figs.

[52] 0.5. 128/583, 128/595 51 Int. Cl. A431: 7/24 [50] Field ofSearch 128/583, 581, 584, 585, 595; 36/37, 71, 82; 264/244, 222

[56] References Cited UNITED STATES PATENTS 2,163,906 6/1939 Cote 128/614 2,348,300 5/1944 Klaus 128/614X 2,572,860 10/1951 128/6'14X 2,760,281 8/1956 128/595 2,821,032 1/1958 128/595 3,121,430 2/1964 O'Reilly 128/595 Primary Examiner-Richard A. Gaudet Assistant ExaminerJ. Yasko Attorney- Michael Ebert PATENTED DEC 8 I970 I N VEN TOR.

l HEEL STABILIZER This invention relates generally to corrective 'foot appliances, and in particular to a heel stabilizer which is insertable in any conventional shoe worn by an individual having weak feet, the stabilizer being adapted to hold the calcaneus of the foot in its proper anatomical position without hindering the normal functioning of the arch and forefoot.

The anatomical structure of the human foot is in the form of a. tripod, the weight of the .body being normally borne upon the heel and the heads of the first and fifth metatarsals. But in a weak or unbalanced foot, the weight is borne upon theheel bone or oscalsis and the head of the first metatarsal only, the third point of supportbeing lacking. As a consequence,when

1 an individualwith weak feet walks in ordinary shoes, there is a tendency of the feet to rollor rotates inwardly, therebyadversely affecting the gait of the walker.

Pronation is present in varying degrees in the feetof most adults. It is the first postural deformity encounteredin the infant when he begins to stand and bear weight. The extentof pronation is significant, for the more marked the pronation,

the greater is the effect of the postural deformity on the overlying body structure. Unless pronation is corrected, it may are incapable of preventing displacement of the heel, bone and the resultant pronation.

The correction in foot attitude effected .by orthopedic shoes is generally at the expense of other important factors involved in foot activity. By shifting the weight-bearing point of the foot to an abnormal position, theorthopedlc shoe arrests or interferes with the proper functioningof the arch and forefoot as a buffer or shock absorber for the body. Hence while the foot posture of the wearer appears to be improved, his ability to walk with comfort may seriously be impaired. Since walking is perhaps the most beneficial form of exercise, orthopedic shoes which tend to discourage walking ultimately do more harm than good. i

Moreover, orthopedic shoes are quite expensive as compared to ordinary shoes. While, from the standpoint of comfort as well as style, it is desirable for an individual to have several pairs of shoes permitting frequent change, the cost of orthopedic shoes is such that few individuals can afford this luxury. But even where the wearer is able to purchase as many orthopedic shoes as he needs, the style of such shoes is rarely pleasing and indeed is often unattractive.

In vie view of the forgoing, it is the main object of the invention to provide a heel stabilizer which is insertable in any conventional shoe in a size normally worn by an individual and which acts to hold in place only the calcaneus of the foot while allowing full functioning of the forefoot and of the arches, the heel stabilizer preventing the tendency of a weak foot to pronate.

A further object of the invention is to provide a heel stabilizer which may be worn with alltypes of ordinary footwear including sneakers and loafers, and which affords acorrective action which in no way detracts from the comfort, appearance or serviceability of the shoes in which the stabilizer is installed.

The salient advantage of the heel stabilizer, as opposed to known corrective appliances, is that it maintains the heel of the foot in the proper anatomical attitude so as to bring about a normal distribution of body weight on the foot structure in all walking positions. Theheel stabilizer is useful in correcting pigeon-toeing and toeing-out due to foot weakness; as well as many other conditions arising from foot weaknesses and imbalances.

. Another object of the invention isto provide a heel stabilizer of the above-described type whose interior wall is contoured to conform :to the heel of the wearer and whose exterior wall is contourable to conform to the heel seat of a conventional shoe, whereby the stabilizer may be properly nested in' the shoe.

Still another object of the invention is to provide a novel technique for producing a heel stabilizer of the abovedescribed type, which technique is simple, rapid and painless, and capable of producinga stabilizer which conforms accurately to the heel of the wearer.

Briefly stated these objects are attained in a stabilizer inthe form of a heel-receiving cup which may be inserted in a conventional shoe, and is constituted by a'heel plate integral with medial and lateral sides, the interior wall of the cup conforming accurately to the size and shape of th the wearers heel in therelaxed .or weight-relieved state. The sides of the cup extend upwardly to substantially the level of the sustenaculum .tali, the medial side extending horizontally to the base of the first metatarsal, the lateral side extending to the head of the fifth metatarsal. Attached to the base of the cup on the exterior wall thereof is a normally rigid thermoplastic body which when heated, is moldable to conform the stabilizer to the heel seat of the shoe 'in which it is inserted. The stabilizer is preferably fabricated of a rigid fiberglassrreinforced plastic to support a heel placed therein against pronation.

For a better understanding of the invention as well as other objects and features thereof, reference is made to'the following detailed description to be read in conjunction with the accompanying drawing wherein:

FIG. 1 is a partial side elevational view showing the position assumed by a .patient, in the initial stage of the technique for manufacturing a heel stabilizer in accordance with the present FIG. 8 is a front elevational view showing the heel stabilizer of FIGS. 6 and 7;

FIG. 9 is a bottom plan view showing the heel stabilizer of FIGS. 68; and

FIG. 10 schematically shows the geometric relationship of the lateral and medial sides of the stabilizer to the foot of the wearer.

In the human foot, the axis of weight-bearing of the tibia .is displaced medially from the axis of weight-bearing of the calcaneus, the degree of displacement being about 1 to 1% centimeters. Thus the tibia and the talus sit on the inner border of .the calcaneus.

In a normalfoot, the passive action of the ligaments and the active role of the muscles complement and supplement each other to maintain the proper alignment of these bones. But in a weak foot, when weight is brought to bear onthe bones, the ligaments fail to'maintain the articulation of the bone surfaces in their proper physiological relationship, as a result of which the calcaneus is forced into pronation.

The'heel stabilizer in accordance with the invention serves to maintain the calcaneus in a vertical plane, thereby bringing the sustenlacutum tali back to its proper position, which will in turn maintain the talus and tibia. By stabilizing the heel of the foot, all the articular surfaces of the midtarsal and metatarsal bones .will then tend to align v The crucial aspectof the present invention resides in the fact that the heel stabilizer functions to hold the'heel in the same position it occupies when inthe relaxed or; unloaded state. When the heel is so oriented, the calcaneus lies in the vertical plane. Though the calcaneus in a weak foot is ordinarily forced into pronation when subjected to body weight, the stabilizer inserted in the shoe of the wearer prevents such displacement, thereby maintaining all other surfaces and bones in their correct physiological alignment.

In order to fabricate a heel stabilizer of this type, the first step, as shown in FIG. 1, is to seat the patient on a chair 1], with his thigh 12 elevated above the seat by means of a small cushion or pad 13 to a degree sufficient to raise only heel 14 of the foot 15 above the floor 16 (or the casting platform). In this position relatively little weight is borne by foot 15.

In" practice, the heel is raised above the floor above a quarter of an inch or so, the heel being thereby suspended. The weight of the leg isthen borne by the forefoot l7 and is equalized across the heads of the metatarsals. Thus the calcaneus now occupies a position in the foot that it assumes in the relaxed or weight-relieved state.

With the patients leg thus supported, the foot is elevated by the doctor or cast maker to the position illustrated in FIG. 2. In this position, several layers 18 of plaster of Paris material in sheet form of the type conventionally used for bandages are applied in wet condition under the 'foot, preferably first around the back of heel 14, beginning above the ankle at the back, and proceeding down and under the plantar surface 19 to the forward ends or heads of the metatarsals. The wet bandage is then brought up to and in engagement with the dorsal surface 20 of the foot.

The foot, thus wrapped in wet bandages, is retained with the heel in the relaxed state, as shown in FIGS. 3 and 4, to allow the bandages to harden to form a cast 21. Upon hardening, cast 21 is removed from the foot, as shown in FIG. 4, this cast serving as a negative or mold from which a positive cast (not shown) is made of plaster or other suitable material using conventional techniques. The contours of the positive cast will therefore exactly match that of the foot in which the negative cast was formed.

The heel stabilizer is then made of a light weight, rigid and structurally strong material which is formed to shape over the positive cast of the heel. Preferably, the stabilizer is fabricated of fiberglass cloth impregnated with a reinforcing epoxy resin. This is done by wrapping reinforced fiberglass matting about the positive cast to mold the matting to the contour thereof.

As shown in FIG. 6, the heel stabilizer, generally designated by letter S, has a heel cup defined by a heel plate 22, a lateral side 23 and a medial side 24, which sides are trimmed to extend upwardly so that their edges edges terminate substantially at the level of the sustentaculum tali. The contour of the interior wall'of the stabilizer conforms exactly to that of the patients heel in the weight-relieved or unloaded state.

In the conventional shoe, the seat of the heel is somewhat flat and does not conform to the heel of the foot. Hence a stabilizer shaped to the human heel will not fit snugly into a shoe, but will have a tendency to rock therein. In order to conform the exterior wall contour of the heel stabilizer to the heel portion of the shoe in which the stabilizer is inserted, the plantar base of the stabilizer is provided with a moldable body 25 made of Neoprene, Prehyl" or other thermoplastic material which is moldable when heated and becomes rigid or semirigid at room temperatures. Thus Prenyl is ordinarily semirigid, but is rendered plastic when heated to approximate- The stabilizer is then removed from the shoe and the shaped thermoplastic'base' cooled under cold water or by refrigeration until the plastic material is hardened. The stabilizer is now useable by the patient and may be inserted in any shoe which he possesses. It is to be noted that Prenyl, when in the moldable state, will not adhere to the surfaceagainst which it is pressed although it will assume the form thereof.

As shown in FIG. 10, the stabilizer sides are trimmed, as by grinding, so that the medial side extends horizontally to the base of the first metatarsal, while the lateral side extends horizontally to the head of the fifth metatarsal. The lateral side prevents forefoot abduction by locking the articulation of the cuboid and fifth metatarsal, and holding the fifth metatarsal shaft.

Where there is no forefoot involvement, and the stabilizer is intended only to maintain the heel position in order, for example, to correct for heel spurs, the form thereof is made such that the medial side extends to the shaft of the first metatarsal and the lateral side extends to the cuboid.

For a flaccid foot condition, wherein a supportive device is required for the metatarsals, the stabilizer is made so that the medial side extends to the head of the first metatarsal and the lateral side to the cuboid, while the anterior portion of the heel plate extends to the heads of all the metatarsals.

It is important to bear in mind that a human foot is constituted by components whose function is supportive of or static and those having a dynamic or propelling function. The static components are the heel bone and the associated tarsal bone, while the dynamic components consist of the metatarsals and phalanges or toes. The. heel stabilizer, in accordance with the invention, maintains the static components in their proper anatomical attitude, thereby correctly orienting the dynamic components which are given freedom to move. Arch supports and similar devices heretofore used for supportive purposes tend to interfere with the proper functioning of the dynamic components, as a consequence of which foot correction is not effected.

While there has been shown a preferred embodiment of the heel stabilizer in accordance with the invention, it will be appreciated that many changes and modifications may be made therein without, however, departing from the essential spirit of the invention as defined in the annexed claims.

Iclaim:

l. A heel stabilizer insertable in a conventional shoe and adapted to prevent pronation of the foot of the wearer, said stabilizer comprising a heel receiving cup whose interior contour conforms to the heel of the wearer in the weight-relieved state, said cup having a heel plate, a lateral side and a medial side of nonthermoplastic material and a thermoplastic body bonded to the exterior of said heel plate, said body being relatively rigid at room temperature and being moldable at an elevated temperature to conform said stabilizer to the heel seat of the shoe.

2. A stabilizer as set forth in claim 1, wherein said stabilizer is formed of reinforced fiberglass.

' base of the first metatarsal of the foot of the wearer.

ly 140 F., which is the average temperature of hot tap water.

This body is bonded to adhere to the reinforced fiberglass stabilizer. In practice; the body 25 is given a horseshoe shape, but when later rendered plastic and subjected to pressure, it is flattened out to take on the form of the surface against which it is pressed. The amount of material in body 25 is no more than is necessary to form a thin layer between the stabilizer and shoe, for otherwise it would elevate the stabilizer in the shoe.

The thermoplastic body 25 is first heated for about 2 to 3 minutes under the hot-water faucet or by other convenient heat sources. The stabilizer is then placed in the heel position of the shoe and pressed down hard to cause the plantar base of the stabilizer to assume the form of the heel seat of the shoe.

metatarsal and the lateral side extends to a position corresponding to the cuboid, while the anterior portion of the heel plate extends to a position corresponding to the heads of all the metatarsals of the foot of the wearer.

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