US2427986A

US2427986A - Corrective insole

Info

Publication number: US2427986A
Application number: US650427A
Authority: US
Inventors: Hyman L Whitman
Original assignee: BF Goodrich Corp
Current assignee: Goodrich Corp
Priority date: 1946-02-27
Filing date: 1946-02-27
Publication date: 1947-09-23
Anticipated expiration: 1964-09-23

Description

Sept. 23, 1947. H. WHITMAN 2,427,986

` v CORRECTIVE INSOLE Filed Feb. 27,` 194e MAX/dw l my-.f

Patented Sept. 23, 1947 UNITED STATES PATENT' vorrlcr.

conanorrva INsoLE Hyman L. Whitman, East Bridgewater, Mass., as-

signor to The B. F. Goodrich Company, New York, N. Y., a corporation of New York Application February 27, 1946, Serial No. 650,427

A more specic object is to provide a corrective insole construction which will aid in achieving better foot balance and bone alignment in order to eliminate sources of foot discomfort and weariness experienced by those having pronated or iiat feet.

Another specic object of the invention is to provide an insole construction which will aid in correcting certain inherent structural defects, namely, to correct shortness or hypermobility of the first metatarsal bone by raising the inside position of the heel suiiiciently to shift a greater portion of the body Weight outward and forward toward the fifth metatarsal bone, thus relieving undue stress upon the inner metatarsals.

The corrective insole of the present invention incorporates a supporting element placed in such position that it rotates the foot to the outside and at the same time raises the inside portion of the heel suiiiciently to shift a greater portion of the body weight toward the fifth metatarsal, thereby effecting a more efiicient weight distribution helpful in those cases of foo-t trouble caused either Iby shortness or hypermobility of the first metatarsal bone.

The invention will now be described with greater particularity with respect to specic embodiments illustrated in the accompanying drawings of which:

Fig. 1 is a plan View of an insole embodying the invention in a preferred'orm, portions of the 6 Claims. (Cl. 36-71) material such las a coated square woven fabric,

and a thicker bottom layer I I of somewhat more resilient material such as the usual rag stockY consisting of an inexpensive rubber composition containing a considerable -amount of fibrous filler.

The top layer I0 has a wing-like extension I2,

extending, as shown in Fig. l, from a point I3 somewhat rearwardly of the arch which'would make it fall approximately under the tripod con-v struction of the foot (formed by the intersection of the navicular, the talus and calcaneus bones of the foot) in the region back of the metatarsal bases to a point I3a well back on the heel, preferably near the end of the calcaneus or heel bone. The wing-like extension or flap I2 is designed to receive a portion of a supporting element insole being shown broken away to disclose the f features of construction and the location of the supporting element.

Fig. 2 is a transverse sectional View taken along line 2-2 of Fig. 1.

Fig. 3 is a composite View consisting of a sectional view taken longitudinally of the insole along line 3-3 of Fig. 1, and showing in superposition, a dotted line representation of the bones of the f oot during actual use of the insole.

Fig. 4 is a transverse sectional View taken vertically through the heel portion of a shoe of the soft athletic type in which the corrective insole of this'invention has been installed and showing in particular detail the transverse disposition of the corrective insole with relation to other parts of the shoe.

Referring `to the drawings: Fig. 1 shows an insole comprising a relatively thin top or cover layer I0, preferably of asmooth hard nished and be adhesively secured thereto in order that the top surface of the insole and a projecting portion of the supporting element may be turned up to lie against the upper of the shoe.

A supporting element or lift desirably comprising two superimposed portions, is adhesively secured between the layers I0, II of the insole in a position immediately beneath the flap I2 and comprises, first, a relatively non-resilient lift portion I4 of high ber rag stock or the like whichA has its longitudinal edges curved inwardly and which has its edges skived to feather edges entirely around the margins and preferably on the r upper face so as to leave one face flat and on the other leave a crown or raised central portion I5 of considerable area as compared to the total area of the non-resilient portion. In a preferred embodiment, shown in Fig. 1, the lift element is shaped somewhat like a pointed ellipse with the longitudinal edges tapered to a common point at each end. The lift portion is preferably inserted between the layers of the insole to a depth at which a substantial portion of the normal curve of the inner border of the foo-t will fall across the crown of the supporting element. The feathered edges should preferably recede smoothly toward the outer border of the foot so as toV eliminate any Ibumps or sharp unevenness in the surface o-f the insole and to permit the iiap I2 to be laid against the side of the shoe without uncomfortable bumps or lumps. The iiat under side of thenon-resilient portion IA is secured to the bottom layer Il. of the insole as by adhesives or stitching and a cushioning portion I6 of resilient material such as alayer of rubber sponge is secured over the crown I5 of the non-resilient portion I4, covering that portion of the crown con' tacted by the weight-supporting surfaces of the foot and preferably extending inwardly far enough to cover all the element I4 which lies Within{vthe boundaries of the normal insole. The cushioning layer I6 -is a most important part of the supporting element in that it serves to elimixnate the harshness of the non-resilient elementL For that reason care must be taken to see that the sponge cushioning position of the. lift element is correctly placed vover the lift element in order to smooth the harsh outlines of the crown and to effect a general cushioning action in the tripod region of the foot. The top layer Hl is secured adhesively to the 'bottom layer l l through.- out their contacting faces and both layers are adhered to the interposed supporting.y element in the zone occupied by it, the Wing-.like fiap I2. being secured adhesively to the extending portion of the non-resilient lift portion Iflvofv thesupporting element.

The insole of this invention may either be built into a shoe or it may be proportioned so that it may be insertedna finished shoe as a supplementary insole -In either Ycase the insole deslralbly is adhered tothe shoe bottom to give a Close. and comfortable twith the flap.Y t2 eX- tending a considerabledistance upward along the upper I1 or side of the shoe and over the quarter lining i8` as Shown in Fie. 4., the. shoe also inoludine vthe customary outsole. i9.; insole 2.0' and. other usuall or desirable elements ofshoe cone structions.

YIn Fig. 3 the bones of the foot 'have been indicated in. dot and dash outline in. their proper relationship to the insoleas obtains during walking. The `bones important to an understanding of the invention vare the metatarsalsjM, the cuneiforms Cu,v and the naviculal N, talus T, and the Caflarleus Ca. It Will be seen. that the thrust exe erted :by the lift portion of' the supporting meme ber will come in the instep region 4rearwanily of the metatarsal headset) as to be substantially below `the tripod construction of; the. foot as indicated` by the arrow at 2|, in contrast to prio-r constructions in which the apex of the supporting member has been placeddirectly belowthe longitudinal arch,l i. e. below theportion of the foot from the rst metatarsal head .bach tothe articulation of the navicular and the inner cuneiform.

Consideration of the nervous system .of the human foot. will reveal that .the plantar or under.. surface of the foot is covered with anetwork ofnerves, particularly the medial 'plantar nerve which extends across. and' between themetatarsal. bones in close proximity thereto.. llt is. easily seenl therefore, that ifr sharp localized pressure is ap,-y plied, as is done in many of the. so-calledarch supports, behind or between the, metatarsal heads, pressure will be exerted upon. these. nerves with concomitant painful symptoms.` Inradditnthe.. plantar surface of the foot is acpmplex mazaof muscleswhich contract the toes .and vaidY inthe. exing ofthe foot while w alki,r.1g .Y Most Iof thesemuscles terminate in tendons ator. near-.the nieta?.l tarsalv heads. Therefore, itr is .easily .seen how. a.. thrust or pressure applied. in themetatarsahzone. during walking will, irritateA @ne bruise these. musclesA and tendons and provide asourceof and irritation. Theheel pt lrtiprisofv the feet, however, are designed to carryas much .as me-.half the .1595211 Weight f the. body and' Varepossessed, of` deep cushions of ilesh andcartilage oyer .the knob ofthe calcaneus .to soften a thrusttheref. upon. ll/l'oreover,V the heel sectipn of the foot. is.. not possessed of as many; articulating muscles, tendons andy nerves and isnotr as easily: sub, jected to irritation as `is the archiegipn andthe region of the metatarsal heads.

With the main thrust ofthe su,pportingv element, in the corrective insole of thisinvention coming as it does under the tripod foot, the arch sections offthe foot comprising the tonstruetiouor the metatarsals, the cuneiforms and the navicular are free to assume their natural arched positions and to loe retained in that position merely by the natural state of tension or tonicity of the liga- .ments of the arch. Except in eXtreme cases of structural defects in the bones and ligaments of the arch no artificial support is necessary but it has 4been found that a large proportion of cases of foot trouble are due to faulty foot posture and weight distribution whereby the feet pronate and throw unusual burdens on the bones and'ligaments of the arch until the strain manifests itself in areas of soreness and tenderness, particularly in the vicinity of the contiguous surfaces of the bones of the arch. Since the present correctiveinsole allows'the bones of the arch toy assume'more nearly their natural positions these traumatic symptoms are alleviated or eliminated.

The 4insole of this invention may be made of' leather or rubber andrubberized fabric, synthetic rubber and resin coated and Vimpregnated fabrics and fibrous materials including the many forms of artificial leathery materials and' others.. 'For' The supporting element Vncolporated in tha be made of. vari.`

insole Vof this invention may also, ous kinds of leather, rubber andA rubberized fab.- ric, synthetic rubber and resin coated, and impregnatedl fabrics and ibrous materials,y as .well as the artificial leathery materials. For example, a supporting element suitable for incorporation into an insole for a soft athletic. shoe bon black loading or fabric-.contaming rag stock" and preferably withtwo or more layers or lamina of fabric in orderto. furnish suilcient body and to prevent crumbling during the skiving-operation. The cushioning portion --ispreferably made ofgsponge rubber but maybet madeof aS/SDOHge- Various. modications. may be.. made without 1 departing. from the-spirit and scope of thai-n4- Ventionas, itV is deinedhy the. following- Claims. i'

I claim: y f

1. AnA insole forsupporting andcushioning-the fooi;` and' for. correctingfeet that tendto prona-te;v

by. raising .the .inner border ofthe foot so as ;t o,

rotate the foot to they. outer lateral.v -bordenzsa-id insole comprising. a(V relatively thin top layer of;

smooth-finished material, a thicker bottomlayer of resilient material, and a Supportingselement comprising a portion of arelatively rigidmaterial and. a. cushioning` portionof spongerrubbei-of sull,-l stantially -thesame ithicknessas said relatively' rigid' material, said top layer of said insole having' or tennis.- shoe may have a relatively non-,resilient lift portion made, of .fabric reinforced rubber of hiehcab a wing-like projection on the inner border thereof extending from a point on the insole which ordinarily would fall approximately beneath the intersection of the navicular, the talus and the calcaneus bones of the foot to a point well back on the heel of the foot, said relatively non-resilient portion of the supporting element having its edges skived on one face to a feather edge so as to leave a crown of considerable area as compared to the total area of the said portion, said supporting element having a portion of its flat side adhered to the said thicker bottom layer and having the said cushioning portion adhered overlying the crown of the non-resilient portion, the skived edges of the supporting element extending out to and being substantially coextensive with the wing-like portion of the insole so as to rest partly under the heel of the foot and partly over the contiguous portions of the shoe upper.

2. An insole for supporting and cushioning the foot and for correcting feet that tend to pronate by raising the inner border of the foot so as to rotate the foot to the outer lateral border, said insole comprising at least two layers, one a top layer of smooth-surfaced material and the other a bottom layer of relatively resilient material, said insole also comprising a built-in supporting element comprising a relatively rigid lift portion and a resilient portion of substantially the same thickness as said relatively rigid portion, said insole having a flap extending laterally from the top thereof from a point which normally would 'fall approximately under the point of intersection of the navicular, the talus and the calcaneus bones of the foot to a point well back on the heel, said flap carrying a portion of the supporting element, the combination when laid along the upper ci the shoe tending to support the side of the foot to prevent rotation inwardly, said relatively rigid portion being shaped similarly to the nap of the insole and having its edges skived on one face to a feather edge to leave a crown of considerable area as compared to the total area of the supporting element, said supporting element being adhered crown face upwards within the said insole with one edge coextensive with said lap on the insole and another feathered edge inserted between the layers of the insole to a depth at which the normal curve of the inner border of the foot falls across the crown of the supporting element, and the resilient portion of the supporting element being inserted between the layers of the insole so as to overlie the crown of the supporting element beneath the weightsupporting surfaces of the foot.

3. In a corrective insole structure, an insole member generally of foot shape, a lift element comprising a relatively rigid portion and a relatively resilient cushioning portion of substantially the same thickness as said relatively rigid portion in superposed relation, said lift element being disposed in the shank region of the insole member but rearwardly of the arch of the foot and extending longitudinally of the insole member from the region normally approximately beneath the intersection of the navicular, the talus, and the calcaneus rearwardly to a position well underneath the calcaneus of the foot, the said element occupying a Zone extending transversely from a region intermediate the normal margins of the insole to a region beyond the normal inner margins of the insole to provide a laterally extending ap, the arrangement being such as to provide a principal upward thrust in the region of the tripod construction of the foot.

4. In a corrective insole structure, a generally curved and tapered element of relatively rigid material disposed rearwardly of the arch of the foot and having its major axis extending from the region of the tripod rearwardly to a point well underneath the calcaneus, a portion of the curved element extending laterally beyond the normal inner margin of the insole to provide an extending nap-like portion, and a cushioning element of relatively resilient material of substantially the same thickness as said relatively rigid material overlying a portion of said curved element within the normal margins of the insole, the arrangement being such as to provide a principal upward thrust in the immediate region of the tripod construction of the foot.

5. An article of footwear having a corrective insole comprising a relatively thin top layer o f smooth-nished material, a thicker bottom layer of resilient material, and a generally elliptical intermediate supporting member of relatively rigid material disposed between said layers extending rearwardly from a point normally approximately beneath the intersection of the navicular, the talus, and the calcaneus at least to a point beneath the lowermost portion of the calcaneous, said supporting member and said top layer extending laterally well beyond the normal inner edge of said insole to form a wing-like projection which is turned upwardly along the inner side of the foot, and a cushioning member of sponge rubber of substantially the same thickness as said relatively rigid material disposed between said supporting member and said top layer and extending over at least that portion of said supporting member which lies within the normal boundaries of l said insole.

6. An article of footwear having a corrective insole structure comprising a generally footshaped insole member and a lift element, said lift element comprising a relatively rigid portion and a superposed relatively resilient cushioning portion of substantially the same thickness as said relatively rigid portion, said element being disposed in the instep region of said insole member rearwardly of the position normally beneath the base of the metatarsals and extending longitudinally of said insole member from the region normally approximately beneath the intersection of the navicular, the talus, and the calcaneus to a position well underneath the calcaneus, said element extending transversely from a region intermediate the normal margins of said insole member to a region beyond the normal inner margin of said insole to provide a projecting flap, said flap being turned upwardly along said normal inner margin.

HYMAN L. WHITMAN.

REFERENCES CITED The following references are of record in the file of this patent:

l UNITED STATES PATENTS Number Name Date 2,089,344 Crull Aug. 10, 1937 1,507,928 Morton Sept. 9, 1924 2,073,775 Baumel Mar. 16, 1937 2,086,242 Sheridan July 6, 1937 806,353 Lipp Dec. 5, 1905 FOREIGN PATENTS Number Country Date 549,313 Germany Apr. 30, 1932