USRE37297E1 - Dynamic orthopedic knee brace assembly - Google Patents

Abstract

A knee brace assembly for various uses, e.g., restricting anterior tibial movement. The knee brace assembly includes a proximal cuff for engaging the wearer's leg above the knee and a distal cuff for engaging the wearer's leg below the knee. The proximal and distal cuffs are linked together by a hinge that permits pivotal movement of the proximal cuff relative to the distal cuff. The proximal cuff has lateral and medial portions each having a slot extending there along. A strap guiding assembly is slidably mounted within each of the slots. Each strap guiding assembly is arranged to slide between a proximal extreme when the wearer's leg is in flexion and a distal extreme as the wearer extends his or her leg. A biasing device biases each strap guiding assembly towards its proximal extreme. A cross-strap, having free ends and a length, is provided for engagement with the wearer's leg. The cross-strap attaches to the wearer's leg below the knee and wraps behind the knee in crisscross fashion. The free ends of the strap attach to the strap guiding assembly. The cross-strap is operative in response to extension of the wearer's leg to pull the strap guiding assembly from the proximal extreme towards the distal extreme thus creating a force counteractive to abnormal anterior movement of the tibia.

Description

This invention relates generally to orthopedic knee braces, and more particularly to knee braces for use by persons having anterior cruciate ligament laxity or insufficiency to protect them from injury due to abnormal anterior tibial movement.

BACKGROUND OF THE INVENTION

Various types of knee braces are shown in the patent literature and are commercially available. The following constitute examples of prior art braces that deal with restricting anterior movement of the tibia: U.S. Pat. Nos. 4,9055,369 (Bledsoe et al.); 5,433,699 (Smith, III); 4,751,920 (Mauldin et al.) and 4,781,180 (Solomonow). The apparatus shown by Mauldin is a knee brace that has a first attachment portion to attach the brace to the wearer's thigh and a second attachment portion to attach the brace to the wearer's tibia and a hinge connected to the medial side of the first and second attachment portions by way of a thigh bar and tibia bar, respectively. An adjustable gearing mechanism located at the hinge permits the wearer to limit the amount of rotation of the tibia bar with respect to the thigh bar. However, this brace suffers from failing to be able to prevent anterior translation of the tibia by the application of posterior pressure directed at the tibia tubercle location. Instead, like its predecessors, the Mauldin apparatus attempts to limit tibial rotation by limiting medial hinge motion.

The apparatus shown by Solomonow is a knee brace having an upper framework attached to the thigh and a lower framework attached to the lower leg just below the knee. These two frameworks are hinged on the medial and lateral sides of the leg (bilateral hinge). A bell crank is pivotally connected to the lower framework. An adjustable screw coupled to one side of the bell crank engages an offset portion of the upper framework whenever the leg is extended. The other side of the bell crank is coupled to a tibial restraining strap. As the leg is extended, the lower framework and bell crank are rotated counterclockwise until the offset of the upper framework contacts the screw, rotating the bell crank in a clockwise direction and thereby tightening the tibial restraining strap against anterior movement of the tibia.

The apparatus as shown by Bledsoe et al. is a knee brace which also utilizes bilateral hinges to connect the thigh support and calf support sections. The bilateral hinges basically comprise adjustable drive plates that alternate the pivoting point of the thigh support and calf support throughout leg flexion and extension. By varying the pivot point at different points throughout leg extension, a counter shearing force is generated to reduce the shearing force created by the quadriceps muscle which cause the undesirable anterior shift of the tibia of the leg.

Other prior art knee braces are disclosed in U.S. Pat. Nos. 3,581,741 (Rosman); 5,277,698 (Taylor); 5,512,039 (White); 3,387,305 (Shafer); 4,240,414 (Theisler); 4,805,606 (McDavid, III); 4,961,416 (Moore et al.); and U.S. Pat. No. 4,854,308 (Drillio).

Examples of prior art knee braces which are commercially available are: Innovative Sports C.Ti., C.Ti.², C.Ti.²Lite, Edge, Edge Lite, Sentry, C180 and MVP all of which are sold by Innovation Sports, Inc. Of Irvine, Calif.; Cincinnati ACL which is sold by Brace Technologies, Inc. Of Cincinnati, Ohio, the OS-5 (TM) non-custom functional knee support which is sold by Omni Scientific, Inc. Of Martinez, Calif.; the Lennox Hill (TM) OTS Brace and Spectralite Brace which are sold by 3M Health Care of Long Island City, N.Y.; the SKO (TM) and TKO (TM) knee orthoses which are manufactured by Orthotic Consultants of Southern California; the ACL model knee brace which is sold by Townsend Design of Bakersfield, Calif.; the DONJOY 4-Point (TM), Gold-Point (TM), Playmaker (TM), and Defiance (TM) all of which are sold by Smith & Nephew Donjoy, Inc. of Carlsbad, Calif.; the Poli-Axial Osteoarthritis Brace which is sold by Generation Orthotics, Inc.; and, the ECKO (TM) II Extension Control Knee Orthosis which is sold by Orthomedics of Brea, Calif.

While the aforementioned patents seem suitable for their intended purposes, it would be a significant advance in the art to provide a knee brace assembly that applies posterior pressure on the wearer's tibia in response to extension of the wearer's leg through the use of a cross-strap that is positioned over the wearer's tibia, wrapped in crisscross manner behind the wearer's knee and attached to biased strap guides slidably mounted to the brace assembly.

OBJECTS OF THE INVENTION

Accordingly, it is a general object of this invention to provide a knee brace assembly which overcomes the disadvantages of the prior art.

It is a further object of this invention to provide a knee brace assembly for restricting anterior movement of the wearer's tibia.

It is a further object of this invention to provide a knee brace assembly for restricting abnormal anterior tibial movement without preventing the wearer from being able to fully extend his/her leg.

It is a further object of this invention to provide a knee brace assembly that is inexpensive to manufacture.

It is a further object of this invention to provide a knee brace assembly that is reliable in operation.

It is a further object of this invention to provide a knee brace assembly that is simple in construction.

It is a further object of this invention to provide a knee brace assembly that is lightweight.

It is a further object of this invention to provide a knee brace assembly that is comfortable when worn.

SUMMARY OF THE INVENTION

These and other objects of this invention are achieved by providing a knee brace assembly for restricting anterior tibial movement. The knee brace assembly includes a proximal cuff for engaging the wearer's leg above the knee and a distal cuff for engaging the wearer's leg below the knee. The proximal and distal cuffs are linked together by a hinge means that permits pivotal rotation of the proximal cuff relative to the distal cuff. The proximal cuff has lateral and medial portions each having a slot extending there along. A strap guiding means is slidably mounted within each of the slots. Each strap guiding means is arranged to slide between a proximal extreme when the wearer's leg is in flexion and a distal extreme as the wearer extends his or her leg. A biasing means biases each strap guiding means towards its proximal extreme. A cross-strap, having free ends and a length, is provided for engagement with the wearer's leg. The cross-strap attaches to the wearer's leg below the knee and wraps behind the knee in crisscross fashion. The free ends of the strap attach to the strap guiding means. The cross-strap is operative in response to extension of the wearer's leg to pull the strap guiding means from the proximal extreme towards the distal extreme thus creating a force counteractive to abnormal anterior movement of the tibia.

DESCRIPTION OF THE DRAWINGS

Other objects and many attendant features of this invention will become readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is an isometric view of a first embodiment of the present invention;

FIG. 2 is an enlarged sectional view taken alongline2—2 of FIG. 1;

FIG. 3 is an enlarged sectional view taken alongline3—3 of FIG. 1;

FIG. 4 is an enlarged sectional view taken alongline4—4 of FIG. 3;

FIG. 5 is a sectional view taken alongline5—5 of FIG. 1;

FIG. 6 is a sectional view taken alongline6—6 of FIG. 1;

FIG. 7 is an exploded isometric view of a first embodiment of the present invention;

FIG. 8 is an isometric view of a second embodiment of the present invention;

FIG. 9 is an enlarged sectional view taken alongline9—9 of FIG. 8;

FIG. 10 is an enlarged sectional view taken alongline10—10 of FIG. 8;

FIG. 11 is an enlarged view of an area shown in FIG. 10 encircled by a line labeled FIG. 11;

FIG. 12 is an enlarged sectional view taken alongline12—12 of FIG. 10;

FIG. 13 is a sectional view taken alongline13—13 of FIG. 8; and, FIG. 14 is an exploded isometric view of a second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now in greater detail to the various figures of the drawings wherein like reference numerals refer to like parts there is shown at20 in FIGS. 1,5 and7 a first embodiment of the dynamic orthopedic knee brace assembly of the present invention. As shown in FIGS. 1 and 5, theknee brace assembly20 is shown attached to a human left leg25 (shown in phantom) having a thigh portion30, aknee35 and leg portion below theknee40. Theleft leg25 is chosen for convenience only and thebrace assembly20 can be affixed to either the right or left leg. Generally speaking, theknee brace assembly20 functions to counteract anterior shifting of the tibia when the anterior cruciate ligament in the illustrated leg is missing or damaged. Such anterior shifting of the tibia occurs for a variety of reasons and often occurs when a person is engaging in physical activities that involve sudden turning to the right or to the left, sudden stopping, jumping, running backwards or other types of movement. Where the anterior cruciate ligament is missing or damaged, such anterior shifting of the tibia can also occur when a person simply extends his or her leg from a flexed position towards its fully straightened position (FIGS.1 and3). Referring now to FIG. 7, theknee brace assembly20 of the present invention comprises three basic parts: a bracingcomponent45, a cross-strap50 and asleeve55. The bracingcomponent45 comprises an upper orproximal cuff60, which is engageable with a wearer's thigh, adistal cuff65, which is engageable with the wearer's leg portion below theknee40, and a pair ofpolycentric hinges70 which pivotally join thecuffs60 and65 together. Straps, used for securing the cuffs to the wearer's leg, are shown generally at75 and80.

Referring now to FIGS. 1 and 7, the bracingcomponent45 is constructed to fit a wearer's leg as will become apparent hereinafter. The upper orproximal cuff60, is formed to fit the anterior portion of the wearer's leg above the knee, and is essentially curvilinear in configuration and shaped to fit over the wearer's thigh30. Theproximal cuff60 has medial andlateral depending portions90 and95, respectively, and a front arcuate portion85 (FIG.1). Theproximal cuff60 is open at the posterior portion so that it may be placed over the thigh30 from the anterior or front. Thedistal cuff65 is similar in construction to the proximal cuff in that it is curvilinearly shaped and formed to fit the anterior portion of the wearer's leg portion below theknee40. It also includes a frontarcuate portion100, amedial depending portion110 and alateral depending portion105.

The proximal anddistal cuffs60 and65 and the polycentric hinges70 are made of lightweight, high impact thermoplastic material which can be formed to fit the contours of the individual wearer's leg. Thecuffs60 and65 may be fabricated from any suitable material, e.g., carbon fiber filament, carbon fiber filament and polymer composite, carbon/titanium composite, woven carbon fiber infused with acrylic resin. Preferably, thecuffs60 and65 are fabricated from a material that is water resistant and non-corrosive to enable the wearer to use the knee brace assembly in a full range of activities including working, walking, running, vigorous athletics and high-impact sports including freshwater and salt water sports.

Referring now to FIGS. 6 and 7, theproximal cuff60 is padded on the inside surface by a durablenon-allergenic foam pad115. In FIG. 6, a top view of theknee brace assembly20 is shown wherein the inside surface of the proximal cuff is provided with a VELCRO® hook patch135 secured, e.g., glued, thereon that is arranged to be brought into engagement the plush exterior surface of thefoam pad115.

As shown in FIG. 7, the polycentric hinges70 are also padded on the inside surface by a durablenon-allergenic foam pad120. The padded cuff and hinges are positioned to absorb anterior or frontal impacts, as well as lateral impacts to the outside of the leg and medial impacts to the inside of the leg.

Referring now to FIGS. 1,6 and7, thecuff strap75 provides releasable securement of theproximal cuff60 to the wearer's thigh30. Thecuff strap75 may be formed of any suitable flexible material, e.g., nylon, and includes anelastic segment77, VELCRO® loop segments76 secured to the inner and outer surfaces thereof by any suitable means, e.g., sewing. Thecuff strap75 also includes VELCRO® hook segment125 disposed at the free ends thereof. The free ends of thecuff strap75 are slipped through and looped aroundelongated slots130 located on opposite sides of theproximal cuff60. Each free end of thecuff strap75 is then folded back onto itself so that thehook segment125 releasably engages theloop segment76 thereby permitting thestrap75 to be tightened or loosened for comfort. Thecuff strap80 provides releasable securement of thedistal cuff65 to the wearer's leg below theknee40 in a similar manner.

Referring now to FIGS. 1,5 and7, the medial andlateral depending portions90 and95 of theproximal cuff60 each include a vertically orientedelongated slot140. As best shown in FIG. 7, astrap guide assembly145ais slidably mounted within theelongated slot140 located on thelateral depending portion95. Likewise, as best shown in FIG. 5, astrap guide assembly145bis slidably mounted within theelongated slot140 located on themedial depending portion90 of theproximal cuff60.

Referring now to FIGS. 3 and 4, thestrap guide assembly145ashown therein includes aring portion146 trapped within abracket portion148. Thebracket portion148 is disposed over the outside surface of thelateral depending portion95 of theproximal cuff60. Thestrap guide assembly145aalso includes aflange portion149 disposed on the inside surface of thelateral depending portion95 of the cuff. Thebracket148 and flange149 portions of thestrap guide assembly145aare held together and slidably mounted to theslot140 by means of arivet assembly147 that enables thestrap guide assembly145ato slidably move within theslot140 between two extremes: a distal extreme, as shown in FIG. 1 and a proximal extreme, as shown in FIG.7.

Referring again to FIG. 3, anelastic band160, e.g., a rubber band, is anchored at one of its ends to theflange149 by any suitable means, e.g., tying. At its opposite end, theelastic band160 is anchored to the inside surface of thelateral depending portion95 of theproximal cuff60 by any suitable means, e.g.,rivet166. In this manner, theelastic band160 serves as a means for normally biasing thestrap guide assembly145ato the proximal extreme within the vertically orientedslot140 as shown in FIG.7.

As best shown in FIG. 5, thestrap guide assembly145bis slidably mounted within theelongated slot140 located on themedial depending portion90 of theproximal cuff60. Thestrap guide assembly145bis similar in construction to thestrap guide assembly145aand includes aring portion165 trapped within abracket portion170 disposed over the outside surface of themedial depending portion90 of theproximal cuff60. Thestrap guide assembly145balso includes aflange portion175, the bracket and flange portions,170 and175, respectively, being held together and slidably mounted to theslot140 by means of arivet assembly180 to enable thestrap guide assembly145bto slidably move between distal and proximal extremes. Anelastic band185, e.g., a rubber band, is anchored at one of its ends to theflange175 by any suitable means, e.g., tying. At its opposite end, theelastic band185 is anchored to the inside surface of themedial depending portion90 of theproximal cuff60 by any suitable means, e.g.,rivet190. In this manner, theelastic band185 serves as a means to normally bias thestrap guide assembly145bto the proximal extreme within the vertically orientedslot140 as shown in FIG.5.

Referring now to FIGS. 1,5 and7, theprosthetic sleeve55 is provided to assist in the attachment of thecross strap50 and may be constructed of any suitable material, e.g., one-eighth inch thick neoprene having a brushed nylon outer surface and a smooth neoprene inner surface. Thesleeve55 is shown as being arranged to be wrapped around and secure to the wearer's leg portion just below theknee40. An alternative sleeve, such as a full patella support sleeve which wraps around and secures to the wearer's thigh and calf, both above and below the wearer's knee could be utilized in substitution for thesleeve55 in accordance with this invention. As best shown in FIG. 7, thesleeve55 is provided with a laterally extendingattachment strap191 on which a VELCRO® hook segment is disposed. As best shown in FIG. 5, once thesleeve55 is wrapped around the wearer's calf just below theknee35, the hook segment on theattachment strap191 releasably engages the plush outer surface of thesleeve55 thereby permitting thesleeve55 to be tightened or loosened for comfort.

Referring now to FIG. 7, the cross-strap50 is formed of a non-elastic flexible web using any suitable material, e.g., nylon, and comprises an interior surface (best shown in FIGS.2 and7), an exterior surface (best shown in FIG. 2) and free ends to which VELCRO® hook patches200 and205 are secured. As best shown in FIGS. 2 and 7, VELCRO® loop segments206 are secured to both the interior and exterior surfaces of the cross-strap50 by any suitable means, e.g., sewing. Positioned on the interior surface of the cross-strap50 approximately midway along the length thereof is a VELCRO® hook patch195 arranged for releasable securement with the plush exterior surface of thesleeve55 at a position on thesleeve55 that lies over the wearer's tibia just below the wearer'sknee35. The positioning of thehook patch195 on the outer surface of thesleeve55 is best illustrated in FIG.1 and by the dottedline199 in FIG.7. The cross-strap50 is also provided with apad59 slidably mounted thereon to be positioned behind the wearer's knee when the cross-strap is secured to the wearer's leg in the manner described below.

Referring now to FIGS. 1 and 5, once thehook patch195cross strap50 is releasably secured to thesleeve55 in the manner described above, the proximal anddistal cuffs60 and65 of the bracingcomponent45 are releasably secured to the wearer's thigh30 and leg portion below theknee40 by attachment withstraps75 and80. As best shown in FIG. 2, a VELCRO® hook patch209 is secured, e.g., glued, to the inside surface of thedistal cuff65 and is provided to engage with the plush exterior surface of thesleeve55 thus providing an added means for securing thedistal cuff65 to the wearer's leg portion below theknee40.

Thereafter, the free ends of the cross-strap50 are crossed behind the wearer'sknee35 and slipped through and looped around thering portions146 and165 of the pivotally mountedstrap guide assemblies145aand145b.Each free end of the cross-strap50 is then folded back onto itself so that thehook patches200 and205 releasably engage theloop segments206 of the cross-strap50 thereby permitting the cross-strap50 to be tightened or loosened for comfort. Theslidable pad59 may be positioned behind the wearer's knee to suit the user's comfort. In accordance with this invention, when releasably securing the free ends of the cross-strap to thestrap guide assemblies145aand145b,the wearer must maintain his or her knee in approximately thirty degrees of flexion. Moreover, the cross-strap must be applied to fit snugly around the wearer's knee but not so tightly as to be uncomfortable.

During use of theknee brace assembly20, when the wearer's leg is fully flexed, the quadriceps muscle exerts only a relatively slight anterior displacement force on the tibia. This displacement force increases significantly as the wearer extends his or her leg closer and closer toward the fully extended position. It can be readily seen that when wearing thebrace20, as the wearer begins to extend his or herleg25 towards full extension, the cross-strap50 tightens geometrically around the wearer'sknee35 above and below the joint line and also applies posteriorly directed pressure to the anterior portion of the wearer's tibia just below the knee. The posteriorly directed pressure exerted against the tibia by the cross-strap50 restrains anterior translation of the tibia.

At this juncture, it is important to point out that anterior tibial translation can result from a number of causes other than displacement forces created by the quadriceps muscle. For example, anterior tibial translation can result from force exerted against the tibia when the wearer is engaged in physical activity that involves sudden turning to the left or right, sudden stopping, jumping and running backwards. The posteriorly directed pressure exerted against the tibia by the cross-strap50 will restrain anterior translation of the tibia during such physical activity.

At the same time, the cross-strap50 applies a tensile force upon thestrap guide assemblies145aand145burging them to move from their normally biased proximal extreme to their distal extreme. As the strap guide assemblies move towards the distal extreme, theelastic bands160,185 will stretch and exert a counteractive tensile force upon the strap guide assemblies resistive to their distal movement. The movement of the strap guide assemblies enables the wearer to straighten his or her leg into full extension while applying increasing amounts of pressure to the wearer's tibia just below the knee.

Referring now to FIGS. 8 and 14, there is shown at300 a second embodiment of the dynamic orthopedic knee brace assembly of the present invention. As best shown in FIG. 14, theknee brace assembly300 shown therein comprises three basic parts: a bracingcomponent305, a cross-strap310 and asleeve315. Theknee brace assembly300 functions to counteract anterior shifting of the tibia that can occur during physical activities that involve sudden turning to the right or left, sudden stopping, jumping or running backwards when the anterior cruciate ligament in the illustrated leg is missing or damaged.

As best shown in FIGS. 8 and 14, the bracingcomponent305 comprises a pair of elongated rigidthigh support members320 and325 extending along medial and lateral sides of the thigh, respectively, and a pair of elongated rigid lowerleg support members330 and335 extending along the medial and lateral sides of the wearer's leg portion below the knee, respectively. The inner ends of the thigh and lower leg support pairs are pivotally interconnected by means of a pair of polycentric hinges340. Thethigh support members320,325, lowerleg support members330,335 andpolycentric hinges340 are made of any suitable lightweight material, e.g., carbon fiber filament, thermosensitive carbon composite materials. Preferably, these components are fabricated from a material that is water resistant and non-corrosive to enable the wearer to use the knee brace assembly in a full range of activities including working, walking, and vigorous athletics. The polycentric hinges340 are padded on the inside surface by a durablenon-allergenic foam pad345.

As best shown in FIGS. 8 and 14, the support members are releasably secured to the wearer's leg (not shown) above and below the knee by means of straps shown generally at350,352,355,360,362,365 and367. Referring now to FIG. 9, a top view of theknee brace assembly300 is shown therein illustrating the manner in which thestraps350 and352 releasably secure the rigidthigh support members320 and325 to the wearer's thigh. Thestraps350 and352, shown therein, each include a VELCRO® hook segment351 disposed at each end thereof. One end of thestrap350 is slipped through and looped around anelongated slot375 located in thethigh support member320 while the other end of thestrap350 is slipped through and looped around anelongated slot380 located in thethigh support member325. One end of thestrap352 is slipped through and looped around anelongated slot385 located in the lateralthigh support member320 while the other end of thestrap352 is slipped through and looped around anelongated slot390 located in the medialthigh support member325. Each end of thestraps350 and352 is then folded back onto itself so that thehook segments351 releasably engage VELCRO® loop segments secured, e.g., sewn, to the outer surface of thestraps350 and352 thereby permitting thestraps350 and352 to be tightened or loosened for comfort. Referring now to FIGS. 8 and 14, thestrap355 slips through and loops aroundelongated slots381 and386 and releasably engages to itself in the manner in which strap350 and352 releasably engage.

Referring now to FIG. 8, straps355,360,362,365 and367 releasably secure the rigid lowerleg support members330 and335 to the wearer's leg portion below the knee in a manner similar to that described above in connection with releasable attachment of the rigid thigh support members to the wearer'sthigh using straps350,352 and355.

Referring now to FIGS. 8 and 14, the rigidthigh support member320 includes a vertically orientedelongated slot395 in which astrap guide assembly400 is slidably mounted. Similarly, the rigidthigh support member325 includes a vertically orientedelongated slot396 in which astrap guide assembly405 is slidably mounted. Thestrap guide assemblies400 and405 each include aring portion410 trapped within abracket portion415. As best shown in FIGS. 10 and 11, thebracket portion415 of eachstrap guide assembly400 and405 is disposed over the outside surface of thethigh support members320 and325. As best shown in FIGS. 8 and 13, eachstrap guide assembly400 and405 also includes aleaf spring420 disposed on the inside surface of thethigh support members320 and325. As best shown in FIGS. 11 and 14, thebracket portion415 and one end of theleaf spring portion420 of thestrap guide assemblies400 and405 are secured together and mounted on opposite sides of theelongated slots395 and396 by means of arivet assembly425 that enables thestrap guide assemblies400 and405 to slidably move within theslots395 and396 between two extremes: a distal extreme, as shown in FIGS. 8 and 13, and a proximal extreme (not shown).

Referring now to FIGS. 13 and 14, as previously mentioned, one end of theleaf spring420 is secured to thestrap guide assemblies400 and405 by means of arivet425. At its other end, theleaf springs420 is anchored to the inside surface of the rigidthigh support members320 and325 by means of arivet assembly430. In this manner, theleaf spring420 serves as a means for normally biasing thestrap guide assemblies400 and405 to the proximal extreme within the vertically orientedslots395 and396, respectively. At this juncture it is important to point out that rather than a leaf spring, alternative means could be employed for biasing the strap guide assemblies towards the proximal extreme, e.g., a coiled spring, an elastic band, a rubber band, etc.

Referring now to FIGS. 8 and 14, theprosthetic sleeve315 is provided to assist in the attachment of the cross-strap310 and may be constructed of any suitable material, e.g., one-eighth inch thick neoprene having a plush outer surface and a smooth neoprene inner surface. Thesleeve315 shown is a full patella support sleeve which wraps around and secures to the wearer's thigh and calf above and below the wearer's knee. As best shown in FIG. 14, thesleeve315 is provided with a laterally extendingattachment strap316 on which a VELCRO® hook segment is disposed. Thesleeve315 also provides apatella opening317 through which the knee can protrude when thesleeve315 is worn. Once thesleeve315 is wrapped around the wearer's leg, theattachment strap316 releasably engages the plush outer surface of thesleeve315 to be tightened or loosened for comfort.

The cross-strap310 is formed of a non-elastic flexible web using any suitable material, e.g., nylon, and comprises free ends, an interior surface, shown in FIG.14 and an exterior surface, hidden from view in FIG.14. The interior surface comprises VELCRO® loop segments440 secured thereto by any suitable means, e.g., sewing, and a centrally located VELCRO® hook patch435 also secured thereto by any suitable means, e.g., sewing. Thehook patch435 is arranged for releasable securement with the plush exterior surface of thesleeve315 just below thepatella opening317 of thesleeve315. This position, as best illustrated by the dottedline399 in FIG. 14, corresponds with the wearer's tibia. The exterior surface of the cross-strap310 comprises VELCRO® hook patches445 at the free ends thereof and a VELCRO® loop segment (not shown) extending therebetween. The cross-strap310 is also provided with a pad359 slidably mounted thereon to be positioned behind the wearer's knee when the cross-strap310 is releasably secured to the wearer's leg.

Once the cross-strap310 is releasably secured to thesleeve315 at the location described above and illustrated in FIG. 14, i.e., just below thepatella opening317, the bracingcomponent305 is releasably secured to the wearer's thigh and leg portion below theknee using straps350,352,355,360,362,365 and367. Thereafter, the free ends of the cross-strap310 are crossed behind the wearer's knee and slipped through and looped around thering portions410 of the pivotally mountedstrap guide assemblies400 and405. Each free end of the cross-strap310 is then folded back onto itself so that thehook patches445 releasably engage the loop segment secured thereby permitting the cross-strap310 to be tightened or loosened for comfort.

During use of theknee brace assembly300, when the wearer's leg is fully flexed, the quadriceps muscle exerts only a relatively slight anterior displacement force on the tibia. This displacement force increases significantly as the wearer extends his or her leg closer an closer toward the fully extended position. It can be readily seen that when wearing thebrace300, as the wearer begins to extend his or her leg towards full extension, the cross-strap310 tightens geometrically around the wearer's knee above and below the joint line and also applies posteriorly directed pressure to the anterior portion of the wearer's tibia just below the knee. This posteriorly directed pressure exerted against the tibia by the cross-strap310 restrains anterior translation of the tibia.

At this juncture, it is important to point out that anterior tibial translation can result from a number of causes other than displacement forces created by the quadriceps muscle. For example, anterior tibial translation can result from force exerted against the tibia when the wearer is engaged in physical activity that involves sudden turning to the left or right, sudden stopping, jumping and running backwards. The posteriorly directed pressure exerted against the tibia by the cross-strap310 will restrain anterior translation of the tibia during such physical activity.

At the same time, the cross-strap310 applies a tensile force upon thestrap guide assemblies400 and405 urging them to move from their normally biased proximal extreme to their distal extreme. As best shown in FIG. 13, as the strap guide assemblies move towards the distal extreme, theleaf springs420 will compress and exert a counteractive tensile force upon the strap guide assemblies resistive to their distal movement. The movement of the strap guide assemblies enables the wearer to straighten his or her leg into full extension while exerting additional counteractive force to prevent anterior translation of the tibia.

Claims (29)

I claim:

1. A knee brace assembly for restricting anterior translation of a wearer's tibia, the wearer also having a leg including a thigh, a knee and a leg portion below the knee, said knee brace assembly comprising:

a. first means for engaging the wearer's thigh, said first means comprising a lateral portion positioned over the lateral side of the wearer's thigh and a medial portion positioned over the medial side of the wearer's thigh, said lateral and medial portions each having a slot extending there along;

b. second means for engaging the wearer's leg portion below the knee;

c. hinging means linked to said first and second means to permit pivotal movement of said first means relative to said second means;

d. strap guiding means slidably mounted within each of said slots, said strap guiding means being arranged to slide between a proximal extreme when the wearer's leg is in flexion towards a distal extreme as the wearer extends his or her leg;

e. biasing means resiliently biasing said movable strap guides towards said proximal extreme; and,

f. a cross-strap provided for engagement with the wearer's leg, said cross-strap comprising free ends and a length therebetween, a portion of said length comprising tibial pressure application means, said cross-strap being attachable over the wearer's leg with said tibial pressure application means located over the wearer's tibia, said cross-strap wrapping behind the wearer's knee in a crisscross manner, the free ends of said cross-strap being attachable to said strap guiding means and in response to extension of the wearer's leg said cross-strap tightening geometrically around the wearer's knee and pulling said strap guiding means from said proximal extreme towards said distal extreme thus enabling said tibial pressure application means to provide resistance to the anterior movement of the tibia.

2. The knee brace assembly of claim1 wherein said first means comprises a proximal cuff engageable with the wearer's thigh and wherein said second means comprises a distal cuff engageable with the wearer's leg portion below the knee.

3. The knee brace assembly of claim2 wherein said proximal cuff additionally comprises an arcuate portion for engagement with the anterior portion of the wearer's thigh and said distal cuff additionally comprises an arcuate portion for engagement with the anterior portion of the wearer's leg below the knee.

4. The knee brace assembly of claim2 wherein said medial and lateral portions of said proximal cuff and said medial and lateral portions of said distal cuff are pivotally connected to said hinging means.

5. The knee brace assembly of claim2 wherein said biasing means comprises an elastic band anchored at one end to said proximal cuff, said elastic band being connected at its opposite end to said strap guiding means.

6. The knee brace assembly of claim2 wherein said biasing means comprises a spring anchored at one end to said proximal cuff, said spring being connected at its opposite end to said strap guiding means.

7. The knee brace assembly of claim6 wherein said spring is a leaf spring.

8. The knee brace assembly of claim2 wherein said proximal cuff additionally comprises a longitudinal axis, said slots extending parallel to said longitudinal axis.

9. The knee brace assembly of claim2 wherein said proximal and distal cuffs are formed of lightweight, high-impact thermoplastic material.

10. The knee brace assembly of claim2 wherein said proximal and distal cuffs are formed of a carbon fiber filament material.

11. The knee brace assembly of claim2 additionally comprising a sleeve encircling the wearer's leg below the knee, said cross-strap being releasably attachable over said sleeve.

12. The knee brace assembly of claim11 wherein said distal cuff is engageable with the wearer's leg over said suspension sleeve.

13. The knee brace assembly of claim2 additionally comprising adjustably tightenable first strap means for engaging said proximal cuff to the wearer's thigh and adjustably tightenable second strap means for engaging said distal cuff to the wearer's leg portion below the knee.

14. The knee brace assembly of claim13 wherein each of said first and second strap means includes an elastic segment.

15. The knee brace assembly of claim1 wherein each of said medial and lateral portions comprises a rigid thigh support member engageable with the wearer's thigh and wherein said second means comprises a pair of rigid calf support members engageable with the wearer's leg portion below the knee.

16. The knee brace assembly of claim1 wherein said cross-strap is non-elastic and adjustably tightenable to selectively vary the magnitude of said force counteractive to abnormal anterior movement of the tibia.

17. The knee brace assembly of claim1 wherein said hinging means comprises a pair of hinges positioned over the medial and lateral sides of the wearer's knee.

18. The knee brace assembly of claim17 wherein said proximal and distal cuffs and said hinges are lined with non-allergenic foam padding for direct engagement with the wearer's skin.

19. The knee brace assembly of claim17 wherein said hinges are polycentric hinges.

20. The knee brace assembly of claim1 wherein said strap guide means are pivotable.

21. The knee brace assembly of claim1 wherein said cross-strap is adjustable.

22. A knee brace assembly for restricting anterior translation of a wearer's tibia, said knee brace assembly comprising:

a. a rigid, inelastic upper cuff adapted to be secured to the thigh;

b. a rigid, inelastic lower cuff adapted to be secured to the leg below the knee;

c. a hinge connecting said upper and lower cuffs to permit rotational movement of said upper cuff relative to said lower cuff;

d. a strap comprising a pair of free ends and an intermediate section therebetween, said intermediate section of said strap being attachable over the wearer's tibia at a location below said hinge and interior of the lower cuff, said strap crossing upon itself, said free ends of said strap attaching to said upper cuff, said strap being arranged to tighten geometrically around the wearer's knee in response to extension of the wearer's leg to apply a force thereto, said force providing resistance to the anterior movement of the tibia.

23. The knee brace assembly of claim22 wherein said strap is formed of a non-elastic flexible web and is adjustably tightenable to selectively vary the magnitude of said force counteractive to abnormal anterior movement of the tibia.

24. The knee brace assembly of claim22 additionally comprising a sleeve adapted to encircle the wearer's leg below the knee, said strap being releasably securable over said sleeve.

25. The knee brace assembly of claim22 wherein said cuff additionally comprises a plurality of rings attached thereto, said strap being securable to said cuff by slipping said free ends thereof through said rings and looping said free ends therearound.

26. The knee brace assembly of claim24 wherein said sleeve comprises a plush exterior surface and wherein said strap includes a hook patch disposed on the length thereof, said hook patch being releasably securable to the plush exterior surface of said sleeve at a position that lies over the wearer's tibia just below the wearer's knee.

27. The knee brace assembly of claim22 additionally comprising a plurality of straps for securing said cuff to said thigh.

28. A knee brace assembly for restricting anterior translation of a wearer's tibia, said knee brace assembly comprising:

a. a pair of supports, one of said pair adapted to be secured to the medial side of the leg, the other of said pair adapted to be secured to the lateral side of the leg, each of said pair of supports comprising a rigid, inelastic upper portion adapted to be secured to the thigh and a rigid, inelastic lower portion adapted to be secured to the leg below the knee, each of said pair of supports additionally comprising a hinge connecting said upper and lower portions to permit rotational movement of said upper portion relative to said lower portion;

b. a strap comprising a pair of free ends and an intermediate section therebetween, said intermediate section of said strap being attachable over the wearer's tibia at a location below said hinge and interior of the lower portion of said supports, said strap crossing upon itself, said free ends of said strap attaching to said upper portion, said strap being arranged to tighten geometrically around the wearer's knee in response to extension of the wearer's leg to apply a force thereto, said force providing resistance to the anterior movement of the tibia.

29. The knee brace assembly of claim28 additionally comprising a plurality of straps for securing said pair of supports to the wearer's thigh.

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