Abstract:
A shoe insert that can be customized by the user to control pronation of the foot and to relieve or reduce stress at painful areas of the foot comprising a sheet of a natural material such as leather or a synthetic resin such as high density polyethylene capable of being deformed to the shape of the foot by the weight of the user. The sheet includes fastening hook or loop material on at least one surface whereby detachable cushioning elements can be attached to the film. The fastening material attached to the sheet is preferably a layer of loop cloth that continuously covers one or both surfaces of the sheet. The cushioning pads also contain a sheet of loop or hook material on one or both surfaces. When the insert with attached, spaced pads is placed in a shoe, the sheet deforms around and between the compressible pads due to the weight of the user and retains the shape when the weight is removed.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a Continuation In Part of a pending application Ser. No. 08/157,709, filed Nov. 24, 1993, now U.S. Pat. No. 5,799,414, which is a Continuation in Part of application Ser. No. 07/957,984, filed Oct. 26, 1992, now abandoned, which is a Continuation In Part of application Ser. No. 07/690,661, filed Apr. 24, 1991, now issued on Oct. 13, 1992, as U.S. Pat. No. 5,154,682, which is a Continuation In Part of application Ser. No. 07/407,145, filed Sep. 14, 1989, now abandoned. 
    
    
     TECHNICAL FIELD 
     The present invention relates to insoles for shoes and, more particularly, this invention relates to an adjustable orthotic by which the eversion and abduction of the tarsal and metatarsal joints can be controlled by the user. 
     BACKGROUND OF THE INVENTION 
     It has been recognized that many of the minor and major traumatic conditions of the foot, leg and knee can be caused by the misalignment of the joints in the foot. These conditions can be hereditary such as the presence of a longer or shorter leg, can be acquired through traumatic injury or can be caused by repetitive stress or strain on the joints experienced during industrial or athletic activity. 
     Misalignment of the foot can cause minor trauma such as inflammation, blisters, rashes, calluses, corns, ingrown toe nails or more aggravated conditions such as bunions or bone spurs, typically in the heel area. Over-the-counter insoles are available to relieve minor discomfort. However, they are available in fixed sizes and thicknesses. It is possible to reduce discomfort and promote healing of inflamed areas by custom-cutting thick cushioning products such as Moleskin® into pads which can be locally adhered to the traumatic area or adjacent to the traumatic area. Pads and insoles only treat the symptoms of the misalignment and simply reduce irritation and attempt to prevent further trauma by reducing pressure, rubbing, or abrasion on the sensitive area of the foot. Sometimes surgery is utilized to remove the calluses, corns or bunions. 
     A more scientific approach has been to develop customized biomechanical devices that are intended to correct the misalignment of the joints. These devices, known as orthotics, are prescribed by medical specialists such as orthopedic doctors, podiatrists or doctors specializing in sports medicine. After extensive physical measurements of the patient, a plaster impression of the foot is taken. The orthotic is manufactured from the impression to specifications provided by the doctor as to the degree of pronation correction required. A soft layer of foam can be applied to the top or bottom surface of the orthotic to provide comfort and to prevent the orthotic from sliding when in a shoe. 
     Orthotics are very expensive, on the order of several hundred dollars a pair. Since they are so expensive, they are usually designed to provide the final correction. The degree of correction can be so severe that the orthotic causes such pain and discomfort to the patient, that it discourages usage of the orthotic and eventually it is no longer used. It is not possible to adjust the fit of the hard plastic orthotic. 
     STATEMENT OF THE PRIOR ART 
     Boisvert, et al. (U.S. Pat. No. 4,813,157) discloses a shoe insert in which the thickness of the arch region of a shoe insert can be changed by peeling off superimposed films of padding material. This product is not found on the market. This is probably because the films are adhesively secured and residual adhesive can transfer to socks and/or collect on the surface of the permanent insole. The thickness adjustment is limited to one area of the insole. 
     Greenwalt (U.S. Pat. No. 4,694,590) discloses an arch support unit containing preformed resilient elements located in the arch area. The support is fastened to the shoe by hook and loop fastener elements located in the heel portion of the support and adhered to the support and to the insole of the shoe. The heel cushion disclosed by Scheuerman (U.S. Pat. No. 4,928,404) contains a soft insert of silicone rubber opposite the location of a heel spur in the patients heel. 
     Andrews (U.S. Pat. No. 4,793,078) discloses a molded, resilient foam shoe insert having depressions 18 in the heel and in the arch support region. The depressions can be filled with adhesively secured, resilient plastic inserts 19 or may be left empty as dictated by the comfort of the wearer. 
     Engle (U.S. Pat. No. 4,930,232) discloses a multilayer laminated permanently adhered shoe insole formed of materials of different shore hardness. 
     Kristan (U.S. Pat. No. 2,928,193) discloses a composite leather-cork shoe lining filled with resilient pads of sponge or with foam rubber glued to the lining. Bittner (U.S. Pat. No. 3,143,812) discloses a thermoplastic insole that can be sized to shape by tearing off portions of the sole along heat sealed seams. 
     The prior insoles were mainly designed to alleviate pain and discomfort. Most of these products were formed of soft resilient materials having no memory or very hard, rigid materials that must be preformed to a desired shape. Adjustable thickness is provided only in set locations and usually by removing pads to form cushions opposite painful areas of the foot. 
     An insole having provision for placement of pads of varying thickness anywhere along the bottom surface of an insole is disclosed and claimed in application Ser. No. 07/690,661, filed Apr. 24, 1991, the disclosure of which is expressly incorporated herein by reference. The insole is formed of a deformable plastic with memory. The bottom surface contains longitudinal strips of loop or hook material along the bottom surface of the insole. The surface may also contain an index scale for locating the correct place to position a pad. 
     STATEMENT OF THE INVENTION 
     The present invention provides a further improvement in the design of an insole that allows it to perform as an orthotic. The insole can be modified by the user to contain elevated and/or relieved areas anywhere on the insole to form an orthotic-like device. By trial and error placement of pads of varying thickness on the bottom surface, letting comfort or discomfort be the guide, the user can create a customized therapeutic device capable of relieving pain and stress and capable of biomechanically correcting or alleviating misaligned conditions in the patient&#39;s foot. More expert alignment can be provided by a doctor of medicine trained in correcting misalignment of the feet. 
     The orthotic of the invention provides infinite adjustability in the location and thickness of the orthotic at any location. The orthotic can be adjusted and shaped at a doctor&#39;s clinic. The custom-shaped orthotic can be the permanently prescribed orthotic or can be a temporary device until a permanent orthotic is fabricated. The custom-configured orthotic can be shaped to provide only a fraction of the correction initially and the pads can be increased or decreased in thickness and/or location to provide gradual and more comfortable correction. The patient can be provided with a supply of pads of varying thickness and be allowed to change the pads under supervision of the clinic without the expense and inconvenience of numerous visits to the physician. 
     The insole of the invention is designed to permit the pads to be secured to the top or bottom surface. Since feet are symmetrical this allows the same insole to be used on the right or left foot permitting sale of single insoles. The tooling and manufacturing costs are significantly reduced. 
     The invention also includes specially shaped inclined ramps which when appropriately located provide pronation correction. The invention also provides pads with all edges smoothed to provide comfort to the user. The invention also relates to use of improved materials and manufacturing processes to form the insole. 
     These and other features and many attendant advantages of the invention will become apparent as the invention becomes better understood by reference to the following detailed description when considered in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view in section of an adjustable shoe insert according to the invention; 
     FIG. 2 is a view in section taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a view in elevation taken in the direction of lines  3 — 3  of FIG. 1; 
     FIG. 4 is a view in section of another embodiment of an adjustable shoe insert; 
     FIG. 5 is a view in elevation of the shoe insert of FIG. 4 shown with the lowermost layer being peeled away; 
     FIG. 6 is a view in section of the shoe insert of FIG. 4 illustrated being inserted into a shoe; 
     FIG. 7 is a view in section of a thick pad for attachment to the shoe insert of the invention; 
     FIG. 8 is a view in section of a thin pad for attachment to the shoe inserts of the invention; 
     FIG. 9 is a view in section of an inclined pad; 
     FIG. 10 is a view in section of a pad having rounded outer edges; 
     FIG. 11 is a view in section of a stacked assembly at a plurality of ads; 
     FIG. 12 is a view in section of a pad having a cavity disposed in the metatarsal region; 
     FIG. 13 is a view in section of a pad having a cavity over the heel region; 
     FIG. 14 is a view in elevation showing the assembly of an inclined pad to the top surface a shoe insert; 
     FIG. 15 is a view in section taken along line  15 — 15  of FIG. 14; 
     FIG. 16 is a view in section showing an inclined pad in dotted lines attached to the opposite side of a shoe insert; 
     FIG. 17 is a view in section taken along line  17 — 17  of FIG. 16; 
     FIG. 18 is a view in elevation showing attachment of pads to the metatarsal and heel regions of a double-sided shoe insert; 
     FIG. 19 is view in section taken along line  19 — 19  of FIG. 18; 
     FIG. 20 is a view in section of a further embodiment of a shoe insert including a resilient layer; 
     FIG. 21 is a view in elevation of a still further embodiment of a shoe insert containing a location guide; 
     FIG. 22 is a view in section taken along line  22 — 22  of FIG. 21; and 
     FIG. 23 is a plan view showing a kit of a shoe insert and cushion pad elements of varying thicknesses. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIGS. 1-3, the shoe insert  10  of the invention is a multilayer laminate in the shape of a shoe insole. The insert  10  comprises a base layer  12  and an outer pad attaching layer  14 . The base layer  12  preferably contains a sheet of cloth having loops  16  to which compressible pads having a layer of hooks can attach. The attachment layer can form the upper surface of an insole or be disposed toward the bottom surface. The layer  14  is attached to the base  12  by bonding, suitably by means of a layer  18  of adhesive. Optionally a cushioning layer  20  of closed cell foam such as Poron or other elastomeric material can also be present. 
     The base preferably contains a continuous, non-compressible sheet of a flexible but deformable sheet of natural material or synthetic organic resin with memory such as a 10-100 mil thick sheet of thermoplastic resin such as a vinyl resin, polyethylene or polypropylene, preferably a high density polyethylene (HDPE), preferably from 10 to 30 mil. A non-compressible sheet of flexible but deformable material such as leather can also be utilized. Under the force of the weight of the user, cushion pads placed on the lower surface of the sheet will compress and the sheet of resin will deform and mold to the shape of the foot forming gradual ramps as the sheet deforms around and between pads. The sheet will also deform into cavities formed in pads such as shown in FIGS. 12 and 13 and into cavities formed between adjacent pads. The base sheet preferably is not foamed and does not contain any open or closed cells. Organic materials such as HDPE and leather also present a low friction, seamless surface when used as the upper surface of the insert. The smooth surface reduces irritation and can result in reduction of inflammation and swelling. 
     The loop fabric is preferably formed of a synthetic resin such as a polyamide material (e.g., Nylon®) and contains a loop surface adapted for releasable engagement by hooks. The loop fabric is commercially available laminated to foam backing layers such as polyester or polyurethane foam cores in various thicknesses. These materials have been used in industrial applications such as display panels office partitions, bulletin boards, etc. These loop fabrics are washable with water and detergent or can be cleaned with organic solvent to remove common stains. An example of a commercial loop cloth is Veltex Bright materials. 
     The Veltex nylon cloth materials have a thin, low profile and will not fray. They are available in many colors and can be attached by pressure sensitive adhesives, tapes, ultrasonic, or thermal bonding. 
     Referring now to FIGS. 4-6, a cloth layer  22  and foam layer  20  are adhered to the deformable base  26 . The lower surface of the base contains a layer  28  of adhesive covered by a protective sheet  30 . As the sheet  30  is peeled from the top edge  32  of the shoe insert  34 , the adhesive layer  28  is exposed. When the insert is placed in a shoe  36 , the adhesive layer  28  will adhere to the surface  38  of the insole. The protective sheet  30  is then removed. The cloth layer  22  is exposed for adherence of pads containing cooperatively engaging hook material. 
     The preferred hook materials used with the pads are also preferably formed of a thin, low profile, non-frayable material. The hooks can form bonds with the loop material of from 20 to 100 pounds per inch, usually around 60-80 pounds per inch. Preferred materials have good elongation properties. Again the preferred hook materials are formed of Nylon. They can be precoated with adhesive. A suitable commercial material is ULTRA-MATE hook materials. 
     Various pad configurations are illustrated in FIGS. 7-13. Each pad contains a cushioning layer formed of a resilient material, suitably a closed cell foam such as PORON. The pads can vary in thickness but generally are from about ⅛ inch to about ½ inch in thickness. The hook material is bonded to the cushioning layer by adhesive, thermal or ultrasonic bonding or by adhesive tape. 
     Referring now to FIG. 7, a thick pad element  40  has a cushioning layer  42  attached to a layer  44  of hook material by a film  46  of adhesive. The thin pad element  48  shown in FIG. 8 contains a thinner layer  50  of cushioning material. The pronation pad  52  illustrated in FIG. 9 includes an inclined cushioning layer  54 . The pad  56  illustrated in FIG. 10 has rounded edges  58 ,  60  and can include a top layer  62  of hook or loop material so that pads can be stacked as shown in FIG.  11 . 
     In FIG. 11 the lowermost pad  70  has a bottom hook layer  72  attached by adhesive film  74  to a cushioning layer  76  and an upper loop cloth layer  78  attached to the cushioning layer  75  by an adhesive film  80 . 
     FIGS. 12 and 13 illustrate pads with apertures which can relieve pressure when placed under sensitive areas of a foot. The larger pad  80  shown in FIG. 12 has a large oval aperture  82  cut out of the middle of the pad. The edge  84  of the cut-out is preferably smoothed or chamfered to provide comfort to the user as his foot enters the aperture  82 . The attachment surface is formed of detachable material such as hook cloth  86  or loop cloth, not shown. The pad  80  can contain an internal layer  86  of cushioning material and an outer layer  90  which can be a smooth cloth such as loop cloth as shown in FIGS. 18 and 19. 
     The smaller pad  100  shown in FIG. 13 has a circular opening  92 , otherwise the construction is identical to that of pad  80 . The pad  100  is intended to be placed over inflammations on or in the heel of the user such as a heel spur. Again the edge  94  is chamfered for comfort. The pad can be cut in half and trimmed by the user to form a smaller opening. The two halves are reassembled by placing the openings adjacent each other with the hooks engaging the loops present on the surface of a shoe insert. 
     The pads can be attached to the top surface or bottom surface of the shoe insert. Referring now to FIGS. 14-17, inclined or ramp pad  101  is attached to the loop cloth surface  102  of a shoe insert  110 . The pad  101  has a bottom hook cloth layer  104 , and inclined shaped cushioning layer  106  and an upper smooth layer  108  such as loop cloth. In FIGS.  14  and  15 , the shoe insert  102  is disposed with the loop cloth surface  104  facing upwardly. The pad  101  is attached across the arch and metatarsal area with the thicker edge  112  disposed along the outer edge  111  of the foot. This lift will pronate the foot inwardly to correct bow leg conditions. 
     The loop surface  102  of the shoe insert  110  is disposed downwardly in FIGS. 16 and 17. The hook layer  104  of the pad is attached to the loop cloth  102  with the thicker edge  111  disposed among the inner side edge  116  of the shoe insert along the arch-metatarsal region of the foot. This assembly will pronate the foot outwardly to correct a fallen arch or knock-knee condition. 
     Rather than inverting the shoe insert base, the base  120  as shown in FIGS. 18 and 19 can have a loop cloth layer  122 ,  124  on both the top and bottom surfaces. The cloth layers  122 ,  124  are adhered to a deformable film  126  of HDPE or other resin by adhesive layers  128 ,  130 . Cushioning layers, not shown, may be present beneath the cloth layers. 
     A metatarsal pad  80  can be attached to the top loop cloth layer  122  and a heel pad  100  can be attached to the bottom loop cloth layer  124 , as shown. 
     FIG. 20 illustrates the use of pressure sensitive adhesive transfer tapes to manufacture the pad-receiving base for the shoe insert. Transfer tapes are marketed in the form of a thin strip of pressure-sensitive adhesive preapplied to a release liner and wound into a spiral on a hub. The transfer tapes are preferred over liquid adhesives, hot melt adhesives, staples, waxes or thermal or flame bonding. Heat may distort the cushioning layer or the HDPE base. 
     As the strip of adhesive is released from the liner it is sticky on both surfaces. It is readily automated to be used in continuous manufacturing operations. It is easy to quickly apply a neat precise strip of clean, dry adhesive strips  131 ,  132  such as 3MF-927 transfer tape to both sides  134 ,  136  of cushioning layer  138  such as a 62 mil thick layer of Poron resilient material. 
     By feeding the adhesive coated cushioning layer  138 , a 20 mil thick film of polyethylene  141  and a continuous strip  143  of Veltex Bright loop cloth, a laminate  145  having the cross-section of FIG. 20 is formed. The shoe insert bases are then die cut from the laminate. 
     As an alternative, the loop fabric layer can be flame bonded to the cushioning material as a first operation. The fabric covered cushion layer can be adhesively bonded to the HDPE plastic base by means of adhesive transfer strips. Another alternative is to apply a second layer of loop cloth or loop cloth-cushion laminate to the other surface of the base. 
     FIGS. 21-22 illustrates another embodiment of the invention. The pads must be precisely located. If they intrude under an inflamed area, it is very painful. To aid the user in locating the position, a visual index scale  160  can be bonded to the cushioning layer  162  by a film of adhesive  164  or to the cloth layer  166 . When the scale  160  is bonded to the cushioning layer the cloth layer can be divided into 2 segments  168 ,  170  on each side of the scale  160 . The scale could also be printed or silk-screened directly onto the cloth layer  166 . A film  172  of deformable plastic is bonded by a film  174  of transfer tape or other adhesive means to the other surface of the cushioning layer  162 . 
     The use of strips of hook or loop material instead of a continuous layer is illustrated in FIG.  23 . 
     A good way to deliver the insert to the user is shown in FIG. 23. A blister package  140  includes a pair of low friction insert  142 , each having an index scale  144  thereon, with flanking strips  146  of adhesive or Velcro type fastening material. The user may use the scale to establish and maintain the discrete and movable cushion elements at the best locations that he discover with use. Normally the insert would be supplied fully covered with elements, but only three per insert are shown in FIG. 23 to help make the scale visible. Three groups of replacement cushion elements  150 ,  151 , and  152  are also included that have a variety of thicknesses to help custom shape the insert. Even if the users foot shape requirements change with time, the kit of FIG. 23 allows continuing modification of the insert to an optimal configuration. 
     Sometimes the pads bind to the innersole of footwear during insertion into a shoe. The bottom layer can have a smooth low friction surface such as a thin vinyl or HDPE film. The assembly smoothly slides into the shoe. The bottom layer and/or top layer of the orthotic can include a layer which tricks moisture away from the foot such as polypropylene cloth or synthetic suede. 
     It is to be realized that only preferred embodiments of the invention have been described and that numerous substitutions, modifications and alterations are permissible without departing from the spirit and scope of the invention as defined in the following claims.