US2159054A - Metatarsal cushion - Google Patents

Description

May 23 1939- B. J. SILVER ,72,159,054

ETATARsAL CUSHION Filed Nov. 20. 1956 INVENTOR BENJAMIN J. SILVER ATTORNEYS Patented May .23, 1939 UNITED, sTATEs PATENT OFFICE 13 Claims.

The invention relates to a shoe and more particularly to the conformation of the foot engaging surface of the inner sole of a shoe in the .region of the ball of the foot and the invention,

5 herein disclosed constitutes an improvement and development ofthe invention disclosed in my oopending .application entitled Sole modifying inner sole", SerialV No. 726,738 iiled May 21, 1934.

One of the objects of the invention in this case,

l as was the primary object in the disclosure in the copending application, is to provide an improved form `of inner sole contour which in its cooperative relation to cushioned and uncushioned or inelastic sole interiors will provide a distribution of cushioned supports to supplement and tend to preserve the tissue areas beneath the points of pressure from the bone structure of the foot. Particularly, the. present disclosure features the distributionof Weight upon the heads of the meta- 0 tarsal bones as received on cushioned areas located andarranged so as to distribute the weight loads over enlarged areas of the sole and thus tend to minimize the localizingof pressure areas or spots within limited areas of the shoe sole. i lt'hasbeen found that in the case of persons who stand for long periods of time on their feet, and particularly in the case of elderly people, thc tissues forming the natural cushion at the ball area of the foot becomes thin, loses its elastcity and, not infrequently becomes calloused,

particularly lbeneath the head lof third and fourth metatarsal bones. It has also been found under such circumstances that the heads vof th metatarsal'bones tend to separate with increasein age-'with a resulting tendency to permanently strain and to iiatten the bone structure forming-what is 'generally referred to as the metatarsal'arch. This distortion in the lnatural relation of the bonegskeleton results instrains 40 on the arch, a weakening,I of the connecting liga-.

ment structure,-and the development eventually of serious foot trouble. "This tendency to a shifting of the bone framework from its initially correct structural position becomes more pronounced withelevation in the heel portion'of some modern types of'shoes, particularly womensshoes. f

Accordingly the primary object of the' present disclosure'is to provide a form of shoe and particularly an improved form ofball engaging portion of an inner solejto provide fora zcushioning eilect in' the ball portion of the shoe sole and which' cushion will notonly supplement and tend to defeat presenttendencies towards loss in' resiliency in the sole tissues beneath v`the heads of c5 the metatarsal bones but which will at the same the second,

invention will be in part obvious from an inspectime tend to resist the. lateral spreading o! these heads.

Still another object is to provide for a natural setting or impression formed in the inner sole closely approximating the impression left by the 5 foot when walking over semi-soft ground barefooted.

Broadly, this aspect of the invention is attained simply by providing shallow recesses, concavities or pockets, in the cushioning area at the ball portion of the inner sole and which recesses are accurately designed, located andarranged to receive and maintain in their natural relative position the slight protuberances formed in the wearers sole when standing in correct position to transmit the weight through the heads of the metatarsal.y bones and particularlythrough the w heads of the three middle metatarsal bones.

'I'he invention has for another object the providing of a depth of cushioning material beneath the recesses so formed equal, or at least substantially equal, to the cushioning eilect provided for the sole in the region between the heads of the metatarsal bones and in this way obtain an equality in cushioning eiect both immediately beneath the heads of the metatarsal bones as well as in the adjacent region considered transversely of the line of heads.

Another object of the invention is to provide a. structure which tends to induce the outer half oi.' vthe ball area of the foot to incline more naturally towards the outer and stronger side so that when the weight or the body "is shifted from heel to ball in the physiology of walking the weight will be thrown to the side which nature intended to receive the weight. The highest point of elevation in the cushion in the preferred embodiment of the invention being just back of the head of the rsecond metatarsal bone not only enhances 'the eiect of the outwardly directed natural tilt but also tends to reduce strain on the inner part of the foot not intended by nature to receive body weight strains.

Various other objects and advantages of the tion ofthe accompanying drawings and in part will be more fully set forth in the following par- -'ticular description of two forms of inner soles em- Hbodying the invention, and the invention also consists in certain new and novel features of construction'and combination of parts hereinafter set forth and claimed.

In the accompanying drawing:

Fig. 1 is a vertical sectional view taken' longitudinally through the basic shoe with a sole modifying cushioning insert pad shown in position located with reference to the bone structure at the fore part of the foot shown in side elevation in dotted outline and illustrating a preferred embodiment of the invention;

Fig. 2 ls a plan view looking down upon the inner sole of the basic shoe and with the pad insert as shown in Fig. 1, showing in dotted outline the bone structure particularly at the heads of the metatarsal bones;

Fig. 3 is a vertical transverse sectional view taken on the broken line 3 3 of Fig. 1;

Fig. 4 is a perspective view of the cushioning insert shown in the preceding figures and with one edge partly broken away to show the cross sectional configuration of the pad;

Fig. 5 is a view similar to the mid-portionv of Fig. 1 showing a slightly modified form of the invention; and

Fig. 6 is a transverse sectional view 'of a modilied form of the pad featuring a substantially flat bottom side as viewed along the curved line 6 6 of Fig. 2, in advance of the high point and looking rearwardly.

In the drawing and referring first to the basic shoe construction illustrated in Figs. 1e to 3, there is shown a conventional form of womens shoe comprising an outer sole I0, an inner'sole II, with the edge of the upper I2 secured at its forward portion between the soles and at its rear end secured between the upper sole and the top of the heel I3. In the region beneath the ball of the foot, there is located a ball or metatarsal area supporting pad I4. This .pad is somewhat irregularly elliptical in plan as shown in Figs. 2 and 4 and located in the shoe in position to receive the ball of the foot at itsl advanced and relatively wide end. 'I'his pad is formed of highly ilexible material, such as soft rubber, has an underside I5 substantially flat except in the region beneath the recesses hereinafter described and has a flatly arched'upper side I6. When viewed in plan as in Figs. 2 and 4, the pad is somewhat egg shaped, or differently described, is a at segment of egg form. -The pad is carefully formed with relation to the bone structure of the fore part of the foot, it being noted that it entirely underlies practically the entire second,

third and fourth metatarsal bones designated respectively 2m, 3m, 4m, leaving the first and fifth metatarsal designated respectively tm, im, uncushioned or substantially so particularly in the case of the first metatarsal bone Im.

In the preferred design herein illustrated, the pad has its greatest transverse width or minor diameter in its forward portion and has its forward edge in position suiliciently advanced at least to underlap the heads of the metatarsal bones. Considered lengthwise the pad as herein illustrated extends forwardly a distance just sufcient to underlap the rst proximo phalanges, specifically designated in Fig. 2 as 2p1, 391 and Cpl, of the second, third and fourth toes, leaving all of the phalanges of the first and fifth toes as well as the second and third phalanges of the second, third and fourth toes uncushioned. In

other words there is no intent herein to cushion .the toes as a whole but on the contrary to provide for the toes the conventional form of leather support directly on the inner sole or, of course, the inner sole with its usual sock lining not herein shown. Considered rearwardly the pad underlaps the anterior half of each of the shanks of the second, third and fourth metatarsals and as shown in- Fig. 1 vextends substantially to the juncture of the tarsal and the middle metatarsal bones.

It is a distinctive feature of this pad that it is provided on its upper surface with three shallow recesses, depressions or pockets, designated I1,

shown in Fig. 3. 'Ihe centers'of the three interior recesses I1, I8 and I9 and the two outer half' recesses 2| and 22 are disposed in a curve which when viewed in plan as in Fig. 2 is the curve defined by the centers of the heads of the five metatarsal bones and defines what has been referred to herein as the minor axis of the pad.

' In ord'efr` to maintain equal thicknesses of cushioning material in the interior portion of the pad, the depressions I1, I8 and I9 are matched respectively by downwardly extending projections 2 3, 24 and 25, as indicated in Fig. 3, and the top surface of the inner sole II is correspondingly recessed to .conform to the wavy contour defining the underside of the pad in the area beneath the recesses. In other words the upper surface of the inner sole is provided with three shallow and somewhat irregular circular or perhaps elliptical recesses and two half recesses exactly conforming in shape, relative relation and location as those in the pad. It will be noted from examining opposite sides of the inner sole I I in Fig. 3 that the extreme edges turn slightlyupwardly towards the adjacent sides of the upper and thus forms in effect somewhat flat lateral continuations of the outer half recesses 2| and 22 so that the outer edges of the heads of the first and fifth metatarsal bones are banked against the upturned edges of the leather sole.

The pad in this case, as was true of the pad in the above identified application, has its maximum elevation at the point hp approximately just 'back of the head of the second metatarsal bone or close thereto with a gradual decreasing in thicknessin all directions from this point of'maximum elevation to the feathered edge.

In the modified showing in Fig. 5, the inner leather sole 2 in the region of the ball of the foot is split slightly below its top surface to form a shallow pocket 21 having a. conformation in plan approximating thatof the pad Il hereinbefore described and forming an integral overlapping extremely thin flap 28. A rubber pad 29 the heads of the metatarsal bones as described for the preferred embodiment illustrated in Figs. 1, 2 and 3'. It will be noted that when the flap is cemented to the top surface of the rubber pad it will conform to the rubber surface and will thus form the recesses in the flap, one of which y recesses is shown at 30 in Fig. 5. In the modified form the rubber is concealed from view and there is exposed the usual inner `sole with or `without the sock lining as may be desired.

Even if the rap should not sink into the recesses in the top surface of the pad as originally constructed, the flap soon sinks into the recesses and itself forms corresponding recesses in its upper surface after the shoe has been worn for a while and the same thing becomes truel of the sock lining when simply pasted into position as is usual in such practices. It has also been found in practice that after wearing the shoe for a short time the recesses tend to conform to the contour and relative arrangement of the metatarsal bone heads of the individual user, presumably resulting in a slight compacting of the soft rubber used in the areas of increased pressure and a releasing of the rubber, at least slightly from those areas of less or reduced pressure. Anyhow in use, there is a slight modification and sometimes a deeper recess formed than was originally formed at the factory and with a properly fitted shoe each cushion quickly takes on the peculiarities and forms the complement ofthe ball portion of the foot of the user.

It is understood that the structure herein illustrated in both forms is a factory produced shoe, but it is within the scope of this disclosure to locate a pad 3| having the top recesses or pockets herein featuredbut with a smooth underside 32, that is an underside without the protections 23-'25 engaging the substantially fiat top or slightly concaved top surface of a conventional form of inner sole. In either case thepad is contained in place on the inner sole sor that in effect the rubber pad becomes a xed part of the finished shoe.

The disclosure features the use at the-ball portion ofthe foot of a cushion of limited area and f merely of an extent and configuration to provide a cushioning effect located where it will do the most good. The weight of the body in walking is transmitted at least in part through the heads s of the middle metatarsal bones and to a less extent through the heads of the outer metatarsal bones. Accordingly. the cushioning material in the present disclosure is massed to cushion the body weight shocks' at the middle of the pad leaving the/outer lateral sides of the ball of .the foot largely in engagement with the uncushioning and relatively rigid leather sole as illustrated at opposite sides of the showing in Fig. 3.

While there is the intent toprovide maximum elevation just.ba, of the head of the second metatarsal bone and gradual reducing in thickness from this point to a feathered edge, it is not desirable to do anything which might tend to cause the heads to. separate from each other or otherwise increase theirv intervals or natural relative arrangement. The providing of the head receiving recesses in the top surface of the pad or the top surface of the overlapping flap or sock lining has the effect of tying all five heads together and the deeper the heads press into the pad the greater will be the resistance offered by the' pad to any tendency of the heads to separate.

I claim:

1. In a. shoe, the combination of an outer sole, an inner sole provided at the region of the ball of the foot in its upper surface and spaced from the edges of the sole with a shallow depression, a

one piece metatarsal arch pad tting to said inner sole depression, said pad forming a segment of an egg-shaped form with its major axis extending longitudinally of the shoe and with the portion forming the minor axi's underlapping the heads of the second, third and fourth metatarsal bones and having its opposite edges spaced from the adjacent opposite edges of the inner sole thus leaving the heads of the rst and fifth bones at least partially uncushioned, and said .pad provided on its upper surface with three shallow. elliptical depressions spaced apart transversely and along the minor axis, and located to receive the portion of the sole of the wearer immediately beneath the heads of the second, third and fourth metatarsal bones and said pad in the parts thereof containing these three depressions being of substantially equal thickness thereby to provide lequal cushioning effects under the heads of the three middle metatarsal bones, and said pad having its point of highest elevation located under the shaft of the second metatarsal bone and reducing in elevation gradually in all radial directions from said point and forwardly to a position terminating approximately mid-length of the middle first phalanges.

2. In a shoe, the combinationof an outer sole, an inner sole provided at the region of the ball of the foot in its upper surface and spaced from the edges of the sole with a shallow depression,

a one piece metatarsal arch pad fitting to saidv inner sole depression, said pad forming a segment of an .egg-Shaped form with its major axis extending longitudinally of the shoe and with the portion forming the minor axis underlapping the heads of the second, third and fourth meta-v tarsal bones and having its opposite edges spaced from the adjacent opposite edges of the inner sole thus leaving the heads oi the first and fifth bones at least partially uncushioned, and said pad provided on its upper surface with three shallow, elliptical depressions spaced apart transversely and along` the minor axis, and located to receive the portion of the sole of the wearer immediately beneath the heads of the second, third and fourth metatarsal bones, and said pad in the parts thereof containing these three depressions being of substantially equal thickness thereby to provide equal cushioning effects under the heads of the three middle metatarsal bones.

3. An inner sole for a shoe having a cushioned area of less width than the inner sole, extending longitudinally of the shoe in rear of the third phalanges of the second, third and fourth toe and confined to the metatarsal dome, to the heads 'of the second, third and fourth metatarsal upper side with three shallow depressions located beneath the heads of the three middle metatarsal bones/and on its lower side with three shallow protuberances, one located beneath each depressionwhereby the cushion is of substantially the same thickness in the portions containing the depressions andy protuberances as in the portions therebetween thereby to provide substantially equal cushioning eect to the sole in the areas beneath the heads as in the spaces beneath the heads of the three middle metatarsal bones.

5. In a shoe, means providing a sole engaging surface and including a cushion in the region of the vball of the foot, said cushion provided in rear thereof and said depression tending during use to conform to whatever variations Iin contour may be imposed thereon by the metatarsal head pressing down through the intervening tissue of the foot.

6. A vshoe provided with an inner sole, a cushion on said sole at the ball portion of the shoe, said cushion being egg-shaped in plan with the wider end located beneath the heads ofthe middle metatarsal bones and its narrow endterminating approximately at the junction of the tarsal and metatarsal bones, the forward edge terminating approximately at the center of the middle proximal phalanges and having a curve approximating the curve in the horizontal plane formed by the heads of the metatarsal bones;

'1. A shoe provided at the ball of the foot with a sole engagingpart provided on its upper face with ive shallow recesses, one for each head of the. :live metatarsal bones and each located beheath and conforming substantially tothe underside ,oi' its associated head and cushioning means of highly iiexible material less than the width of the sole at the part thereof containing the recesses overlying said portion and disposed to leave the two outer recesses exposed and the underside of said cushion conforming to the portion of the sole which it engages.

8. A shoe provided at the ball ofthe foot with a pad provided on its upper face with nve sha1- low one for each head of the live metatarsal bones, each located beneath its associated head, the three middle recesses contained within the 'outline of the pad and the two outer rebeing incomplete in outline and substantially blsected bythe adjacent edge of the pad.

9.Ashoe'havlngii:ssoleportionat` terminate beyond the distal heads the ball, of the foot formed at its mid-portion by a rubber cushion and on opposite sides of the rubber cushion by leather, the edge portion of the rubber cushion and the adjacent portion of the leather being recessed to form a shallow depression located beneath the head of one of the outer metatarsal bones.

10. An inner sole fory a shoe split in the resion of the ball of the foot to form a hollow pocket with an integral extremely thin flap overlapping the pocket, a one-piece dat cushion iitted in said pocket and cemented to the ap, said cushion provided on its upper surface with a shallow recess substantially elliptical in plan located beneath a head of a metatarsal bone and said ilap being sumciently thin and flexible to permit the sole of the user to press the ap into and thus take the contour of said recess.

1l. A one-piece soft rubber pad`for a shoe, said pad having substantially a :dat segment of egg form with its upper side provided with a shallow depression for receiving the `head of the second metatarsal and extending lengthwise of the second metatarsal.

l2. A foot corrective appliance consisting of an integral piece of material having a convex top surface and provided with a recess for the head of the second metatarsal shaft, a recess for the head of the vthird metatarsal shaft, and a recess -for they head of the fourth metatarsal shaft, said recesses being of suiiicient length to accommodate substantially the entire length of the respective metatarsal shaft heads, the end portion of the appliance being shaped so as to of the 'metatarsal shafts. i3. A shoe provided at the ball of the foot with a sole engaging part provided on its upper face with iive shallow recesses, one for each head of the ve metatarsal bones, and a cushion of less width than said part covering the three middlerecesses leaving the outer ktwo recesses at least partly exposed. and said cushion provided on its upper side with three recesses, one for each head of the three middle metatarsal bones.

BENJAMIN k.1.v SILVER.

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