Heel stabilizer

United States Patent

ΠΠ 3,545,447

<td> [72]</td><td> Inventor</td><td> Jack J. Silverman 15 Cypress Road, Eastchester, New York 10709</td>

<td> [21]</td><td> Appi. No.</td><td> 745,531</td>

<td> [22]</td><td> Filed</td><td> July 17,1968</td>

<td> [45]</td><td> Patented</td><td> Dec. 8,1970</td>

(54] HEEL STABILIZER

Claims, 10 Drawing Figs.

[52] U.S.CI....................................................... 128/583,

128/595

[51] Int.Cl........................................................ A43b7/24

[50] Field of Search............................................ 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 Hippsetal.................... 128/6Γ4Χ

2,760,281 8/1956 Cosin................... 128/595

2,821,032 1/1958 Helfet......................... 128/595

3,121,430 2/1964 O’Reilly....................... 128/595

Primary Examiner—Richard A. Gaudet Assistant Examiner—J. Yasko Attorney— Michael Ebert

ABSTRACT: A heel stabilizer having a cuplike formation to receive the heel of a foot, the interior wall of the stabilizer being contoured to conform accurately to the heel of the foot of the wearer, a moldable plastic body being attached to the base of the exterior wall to conform the stabilizer to the heel seat of the shoe in which the stabilizer is inserted.

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PATENTED DEC 8 BTC

3,545.447

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3,545,447

·. 2

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 the heel bone or oscalsis and the head of the first metatarsal only, the third point of support being lacking. As a consequence, when an individual with weak feet walks in ordinary shoes, there is a tendency of the feet to roll or rotates inwardly, thereby adversely affecting the gait of the walker.

Pronation is present in varying degrees in the feet of most adults. It is the first postural deformity encountered in the infant when he begins to stand and bear weight. The extent of 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 worsen in time and become a serious source of difficulty.

In order to resist pronation, it has heretofore been the practice to provide orthopedic shoes of special construction containing arch supports, inlays and other foot-supportive devices. Such shoes and devices effectively introduce an additional weight-bearing point that is absent in the normal foot and, as a consequence, undue stresses and strains are imposed on articular surfaces. Moreover, arch supports, inlays and similar devices fail to confine the sides of the foot and hence 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, the orthopedic shoe arrests or interferes with the proper functioning of 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.

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 all types of ordinary footwear including sneakers and loafers, and which affords a corrective 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. The heel 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 is to 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 conven5 tional 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, 1θ and capable of producing a stabilizer which conforms accurately to the heel of the wearer.

Briefly stated these objects are attained in a stabilizer in the form of a heel-receiving cup which may be inserted in a con. ventional shoe, and is constituted by a heel plate integral with ¹⁵ medial and lateral sides, the interior wall of the cup conforming accurately to the size and shape of th the wearer’s heel in the relaxed or weight-relieved state. The sides of the cup extend upwardly to substantially the level of the sustenaculum ₂₀ 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 25 seat of the shoe in which it is inserted. The stabilizer is preferably fabricated of a rigid fiberglasst-reinforced 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 follow30 ing 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 35 invention;

FIG. 2 is a partial side elevational view showing a slightly later stage of the technique;

FIG. 3 is a top plan view illustrating the stage shown in FIG.

2,

FIG. 4 is a partial side elevational view showing a still later stage in the technique;

FIG. 6 is a top plan view showing a finished heel stabilizer in accordance with the invention;

FIG. 7 is a side elevational view showing the heel stabilizer ⁴⁵ of FIG. 6

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 ₅₀ FIGS.6—8;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 tibiais 55 displaced medially from the axis of weight-bearing of the calcaneus, the degree of displacement being about 1 to 1½ centimeters. Thus the tibia and the talus sit on the inner border of the calcaneus.

In a normal foot, the passive action of the ligaments and the 6Q 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 on the bones, the ligaments fail to maintain the articulation of the bone surfaces in their proper physiological relationship, as a result of which 65 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 70 foot, all the articular surfaces of the midtarsal and metatarsal bones will then tend to align

The crucial aspect of the present invention resides in the fact that the heel stabilizer functions to hold the heel in the same position it occupies when in the relaxed or, unloaded state. When the heel is so oriented, the calcaneus lies in the

3,545 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 11, 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 is then borne by the forefoot 17 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 patient’s 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 ofthe 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 patient’s 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 approximately 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 positiori ofthe shoe and pressed down hard to cause the plantar base of the stabilizer to assume the form of the heel seat of the shoe.

,447

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 surface, against 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 ofthe 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.