Abstract:
A knee brace having a hinge assembly comprising an upper segment; a lower segment; a middle linking segment coupled to the upper and lower segments to permit pivotal movement of the upper segment relative to the lower segment; and one or more biasing members anchored to the upper and middle linking segments to resiliently bias the upper and middle segments toward a predetermined alignment. A series of straps connected to the hinge assembly allow attachment of the knee brace to the wearer&#39;s leg.

Description:
BACKGROUND 
     The present invention relates generally to knee braces, and more particularly to a flexible knee brace to be used during sports or other activity. 
     Knee braces are typically used by athletes and persons engaged in vigorous physical activity to protect the knee from injury and to avoid exacerbation of existing injury. There are different types of knee braces, depending upon the need and protection required. 
     Prophylactic braces are used as primary prevention, to stop an injury occurring in the first instance. These braces are usually hinged (either on one side or both sides) and their aim is to prevent excessive movement in the knee joint when an abnormal force is applied to it. These movements may be front to back, side to side or rotational in nature. Rehabilitation braces are used under the supervision of an orthopedic surgeon and/or a physical therapist to control the amount of movement the knee joint is allowed to make, usually after an operation. The idea is that this protects the healing ligament(s) and promotes recovery. 
     Functional braces are mainly used to protect the anterior cruciate ligament (ACL), either after surgery for those who have had a ligament reconstruction performed, or after injury in those who decide against surgery or who are still waiting for their operation. They aim to reduce rotational and front to back movements, the forces that are associated with injury to the ACL. 
     Many of the knee braces on the market today include a “hinge and shell” or a “hinge and strap” design. The first kind of brace incorporates molded shells of plastic and foam connected by a hinge system whereas the latter uses leg and thigh straps for attachment. All of the aforementioned braces require protection such as padding along the medial and lateral sides to support and stabilize the knee. Many of the braces prevent and/or restrict certain movement of the knee. 
     It is a primary object of the invention to provide a knee brace that does not restrict the knee during active movement. It is another object of the invention to provide a knee brace that is lightweight, comfortable and of simple construction. It is a further object of the invention to provide a flexible knee brace that allows repeated flexing and straightening of one&#39;s knee during wear. It is yet another object of the invention to provide a knee brace that assists one in straightening one&#39;s knees, after flexing one&#39;s knees, repeatedly, in activities such as skiing, that require repeated flexing and straightening of one&#39;s knees. 
     SUMMARY OF THE INVENTION 
     These and other objects and advantages are accomplished by a knee brace that serves to assist the wearer in repositioning his flexed knee to an extended position when engaging in sports or activity. 
     Specifically, in one embodiment, the knee brace comprises a hinge assembly having an upper segment, a lower segment, a middle linking segment coupled to the upper and lower segments to permit pivotal movement of the upper segment relative to the lower segment, and one or more biasing members anchored to the upper and middle linking segments to resiliently bias the upper and middle segments toward a predetermined alignment. A series of straps are connected to the hinge assembly to strap the upper, lower and middle segments to a wearer&#39;s leg. 
     In use, the biasing members in the knee brace force the segments in the brace to re-align, which in turn assist the wearer in realigning his legs from a flexed position to an extended position. The knee brace is lightweight, allowing for a full range of motion of the wearer&#39;s legs and easy to slip on and take off. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be more fully understood and appreciated by reading the following Detailed Description in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective view of the knee brace of the present invention; 
         FIG. 2  is a perspective view of the knee brace showing an exploded view of the hinge section; 
         FIG. 3  is a perspective view of the knee brace in a rotated position; 
         FIG. 4  is a perspective view of the knee brace of  FIG. 3  in a succeeding rotated position; 
         FIG. 5  is a perspective view of the knee brace in use on a wearer&#39;s leg; 
         FIG. 6  is a perspective view of the knee brace with an alternate biasing mechanism. 
     
    
    
     DETAILED DESCRIPTION 
     As will be appreciated, the present invention provides an effective device for assisting a skier in re-positioning his legs as he skis. Reference is made to  FIGS. 1 and 2 , which illustrate a hinge assembly  10  of a knee brace  11  (shown in  FIG. 5 ) in a cut-away view to more clearly show operation of knee brace  11 . Hinge assembly  10  comprises three main sections or segments, which affect movement of the wearer&#39;s leg. Upper segment  12  is connected to a middle linking or hinging segment  14  by a pivot pin  16 , permitting rotation about a horizontal axis  18 . A lower segment  20  is connected to middle segment  14  by a pivot pin  22 , permitting rotation around a horizontal axis  24 . Each pivot pin,  16  and  22 , may include a shank for passing through the pivot openings and a cap or head section securely fitted to each end of the shank for maintaining the shank in the opening. The shank is loosely fitted in the opening to allow relative pivotal movement of the hinge members. A stop  26  may be located on middle segment  16  to provide support for upper segment  14 . 
     Anchor pin  28  is positioned in upper segment  12  and anchor pin  29  is positioned in middle segment  14  for anchoring a bias member, which may be a spring, elastic band or the like. Elastic bands  30  are shown positioned on anchor pins  28  and  29  in the Figures. When upper segment  12  and middle segment  14  are in parallel alignment with the longitudinal axis  32  of middle segment  14 , the segments are in a neutral or predetermined position. In this neutral position, the elastic bands  30  are in a normal, unbiased state. As clearly shown in  FIG. 2 , upper segment  12  shows a notch  34  for allowing the positioning of anchor pin  29  on middle segment  14 . As a result, the lower ends of elastic bands  30  are positioned on middle segment  14  and the upper ends of elastic bands  30  are positioned on upper segment  12 . This creates biasing of upper segment  12  and middle segment  14  by bands  30  when segment  12  rotates about axis  18 . 
       FIGS. 3 and 4  illustrate the rotation of hinge assembly  10 .  FIG. 3  shows rotation of upper segment  12  and middle segment  14  about axis  24 . Elastic bands  30  are maintained in neutral or unbiased position as segments  12  and  14  rotate about axis  24 .  FIG. 4  illustrates rotation of upper segment  12  about axis  18 . As segment  12  rotates about axis  18 , it is no longer aligned along the longitudinal axis  32  of middle segment  14 . This causes elastic bands  30  to extend, creating a state of tension. The resiliency of elastic bands  30  will bias segment  12  to its neutral upright position and re-align it with segment  14 . 
     Reference is made to  FIGS. 1 and 2 , which show openings  40  and  41  for placement of anchor pin  28  in order to provide options for the placement of anchor pins therein. This allows one to vary or adjust the tension provided by the biasing member. As shown in the Figures, anchor pin  28  is located furthest from the proximal end  42  of upper segment  12  in order to create the highest amount of tension, when upper segment  12  is rotated about axis  18 . If less tension is desired upon rotation of segment  12 , anchor pin  28  may be inserted into opening  40  or  41  to provide less distance between pin  29  and pin  28 . As the rotation increases, the tension increases, and a greater force will react to “pull back” segment  12  to its upright position. 
       FIG. 5  shows knee brace  11  in position on a wearer&#39;s leg. Hinge assembly  10  is positioned on the lateral side of the knee (as shown), and also on the medial side of the knee to provide support along both sides of the leg. The placement of the hinge assembly  10  is preferably proximate the wearer&#39;s knee joint, such that the hinge assembly  10  is flexed at generally the same location at which the knee is bent. The lower end of band  30  is positioned at or just slightly above pivot axis  18  of segment  14  and also proximate the knee joint. Due to resiliency of hinge assembly  10 , the leg is urged in generally straight configuration when the leg is bent. 
     In an alternate embodiment of the present invention, reference is made to  FIG. 6 , which shows band  30  attached to a string or cable  46 . Cable  46  is positioned on anchor pin  29  at one end and is connected to elastic band  30  at the other end. Elastic band  30  is also positioned on anchor pin  28 , which pin  28  is located a further distance from anchor pin  29  and from the axis of rotation of axis  18 . The connection of elastic band  30  to cable  46  allows for more flexibility and less tension in the rotation of axis  18 . This is optimal for a user who would like less tension applied when bending his knees, but would still desire a slight force to assist in the straightening of his knees. This provides more options and variations for users, who vary in weight, strength and flexibility in their legs, and/or desire less force to straighten their legs. 
     In order to attach the brace to a wearer&#39;s knee, a series of collars or straps may be used. As shown in  FIG. 5 , straps  34 ,  36  and  38  are positioned at the thigh, knee and ankle, respectively, of the wearer. Although three separate straps are shown in  FIG. 5 , it is possible that fewer or greater than three may be used to attach knee brace  10  to the wearer&#39;s leg. Also, the location of the strap onto the wearer&#39;s leg may vary somewhat from the thigh, knee and ankle areas, such as near the calf area, as long as the attachment is effective and comfortable. For example, strap  38  positioned proximate the wearer&#39;s ankle could be located closer to strap  36 , more proximate the wearer&#39;s knee. The straps can be adjusted to provide a snug fit about the wearer&#39;s thigh, knee or calf and/or ankle area. 
     The straps and hinge segments may be made of a lightweight thermoplastic material, lightweight metal, plastic, composite or other similar material. The strap and hinge members may be formed of substantially rigid, or alternatively may be flexible. The straps and hinge segments may be made of the same or different materials. Some examples include lightweight aluminum metal, nylon, polypropylene, polyethylene, and composites thereof, including fiber reinforced composites with glass, carbon, and/or polymeric fibers therein. As a means of attachment, the straps may include an elastic or an inelastic material with a hook and loop fastener, such as a Velcro® fastener to secure the ends of the attachment straps, for easy adjustment for any size leg. Padding may be added to the straps and/or the hinge assembly to prevent direct contact between the hinge assembly and the wearer&#39;s leg. The straps may be attached to the hinge assembly by adhesive, rivets, snaps or similar fastening mechanism. 
     Once the knee brace is fitted to the wearer&#39;s leg, the wearer will have full range of flexion and extension. The movement of knee brace  11  is dependent on the movement of the wearer&#39;s knee. In  FIG. 5 , the wearer&#39;s knee is slightly bent, showing rotation of segments  12  and  14  about axis  24  (as more clearly shown in  FIG. 3 ). As the wearer further flexes his knee, segment  12  will rotate about axis  18  as shown in  FIG. 4 , creating tension in bands  30 . A counteractive force will bias or pull segment  12  to a more upright position, in parallel alignment with the longitudinal axis of segment  14 . The wearer will feel slight pressure from the brace, which will enable the wearer to straighten his leg. The force created to re-align segment  12  in a more upward or in ascending position will assist the wearer in extending or straightening his leg. 
     The knee brace is very useful for a downhill skier. As skier typically serpentines a mountain, he will repeatedly bend and extend his knees. As the skier bends his knees, the resiliency of the bands will pull the skier&#39;s legs back to a straight position. This will assist the skier in “pulling out” of his turns. This brace is useful for someone learning to ski, or for people who may have weak or tired legs. 
     While the invention has been described with reference to exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended embodiments.