Abstract:
A knee brace including an adaptable anterior thigh pad for securing an upper portion of the brace to a user&#39;s thigh wherein the anterior thigh pad automatically adjusts to underlying soft tissue motion during knee and leg movement. The anterior thigh pad includes a flexible upper horizontal connection and a pair of substantially rigid x-crossing connections. The anterior thigh pad tightens and loosens during normal leg flexing and straightening so as to maintain a tight skeletal grip on the users leg while adapting to thigh muscle movement. The individual straps of the anterior thigh pad connecting the thigh pad to the rigid arms of the knee brace are independently adjustable to accommodate any leg size or shape.

Description:
FIELD  
       [0001]     The field of the invention is orthopedic devices, and more particularly, knee braces.  
       BACKGROUND  
       [0002]     The following includes information that may be useful in understanding the present inventions. It is not an admission that any of the information provided herein is prior art, or relevant, to the presently described or claimed inventions, or that any publication or document that is specifically or implicitly referenced is prior art.  
         [0003]     Orthotic devices generally include a substantially rigid biomechanical element that forms the basis of the skeletal support that is required for the majority of these devices, which include braces, supports and splints.  
         [0004]     The human knee generally comprises an articulated joint between the thigh and the lower leg muscles that supports the weight of the human body while the person is standing, walking or running. The knee joint is primarily held together by four ligaments; namely, the anterior and posterior cruciate ligaments and the medial and lateral collateral ligaments. The knee joint can be overly weakened by injuries arising out of cartilage damage and ligament strain, which may be caused, by sports injuries, as well as from everyday exercising, or physiological problems such as osteoarthritis. Thus, the human knee is subjected to a variety of stresses and strains particularly during running and jumping movements. Athletes, in particular, are apt to incur a knee injury as a result of a blow to the knee or to a twisting of the knee, which can commonly occur in various contact sports or high stress sports, such as skiing. Normal aging of the knee joint results in diminished knee stability. Muscle control may be reduced; ligaments become lax and thus less effective.  
         [0005]     There are a variety of knee braces available on the market or through healthcare providers. These range from braces that tend to totally immobilize the knee to flexible elastic bandages that are intended to provide some flexibility while eliminating lateral movement of the ligaments that support the knee. Some of these are braces intended to be worn as a relatively permanent device for long-term wear or braces that are intended to be worn for a short period of time during overly strenuous for a short period of time, for example, for a weakened knee. The braces have as their primary object to allow for bending and straightening the knee while preventing any unnatural movement, which may aggravate the knee ligaments. While the braces are intended to allow for a natural movement of the knee joint while a person undergoes walking, running, jumping, skating, various other athletic activities, they are intended also to prevent sudden movement of the upper and lower legs to one side or the other and to prevent twisting or rotation of the lower leg relative to the upper leg about the vertical axis.  
         [0006]     Typically, the knee braces are held in place by flexible straps, which wrap about the user&#39;s thigh and calf above and below the knee, respectively. In this manner, the rigid hinge of the knee brace remains positioned on either side of the user&#39;s knee so as to mimic the hinged joint of the knee. However, it is not uncommon for the user&#39;s bodily motions to cause the flexible straps to move relative to the person&#39;s leg, thereby misaligning the knee brace with respect to the knee. This movement of the brace straps with respect to the user not only cause misalignment and therefore misapplication of the orthotic device, but also cause irritation of the user&#39;s skin by this unintended rubbing.  
         [0007]     Another problem with knee braces is that they must engage effectively with soft tissue in order to provide the desired support. In many parts of the body the soft tissue will move, for example by expanding or contracting as result of muscle movement. This can cause distal migration of the knee brace with respect to the users leg, which means that the brace is not providing its desired support function. As a soft tissue changes shape, parts of the skin lose contact with the liner of the brace. This reduced contact with the liner can cause the knee brace to lose position, or move relative to the user and therefore become ineffective. The only way of overcoming this problem with existing devices is to tighten the device. This causes discomfort, prevents the skin from breathing, and can irritate the skin about the edges of the device and the liner.  
         [0008]     The objective of any rigid knee brace is to exert a predictable force on the user&#39;s underlying skeleton. In particular, the objective is to exert a force on the tibia with respect to the femur in the user&#39;s body mass above the knee. By definition, knee braces are applied to soft tissue lying between the brace and the user&#39;s skeleton. Soft tissue is mobile and moves in a cycle corresponding to a user&#39;s gait, whether it be through running, walking or other physical movement common to the human knee. The most mobile soft tissue is the quadriceps mechanism lying in front of the femur in the anterior thigh region. The central reference point for a knee brace is the knee joint line. In construction, a knee brace would use a rigid joint mechanism which mimics the movement of the knee, which is not just a simple hinge. Since each user&#39;s body shape is unique, the exact interface between the knee brace and the user&#39;s leg cannot be predetermined in the manufacture of such a device.  
         [0009]     The central reference point for a knee brace is the knee joint line. In construction, a knee brace would use a rigid joint mechanism that mimics the movement of the knee, which is not just a simple hinge. Because each user&#39;s body shape is unique, the exact interface between the knee brace and the user&#39;s leg cannot be predetermined in the manufacture of such a device.  
         [0010]     The function of the tibial section attached to this joint or central axis is to “fit and grip” the tibia and exert a force on it. In ligament instability bracing is intended to prevent anterior translocation of the tibia with respect to the femur. It is also desired to prevent the tibia deforming into varus (bow legged) or valgus (knock kneed). This is important because often injuries to the collateral ligaments coexist with cruciate ligament related pathology, and resulting instability. In bracing for osteoarthritis the objective is to exert an unloading force on the side of the knee joint most affected by degenerative pathology. This is achieved by “pushing” the tibia into a slight valgus deformity, or less frequently, a slight varus deformity.  
         [0011]     The function of the femoral, or thigh portion is to stabilize the central axis, or knee joint, and to provide a lever arm or counteracting force for the tibial section. Ideally the central axis, and attached tibial section, remain in a stable position relative to the actual underlying knee joint. Ideally the “lever arms” extending up the thigh remain in a stable position aligned with the underlying femur.  
         [0012]     An improved knee brace is described in applicant&#39;s co-pending application entitled “Knee Brace”, filed on even date herewith, which application is hereby incorporated by reference herein in its entirety.  
         [0013]     Applicant&#39;s co-pending application describes a knee brace which can more readily conform to a particular user&#39;s leg, such that the straps fit snugly, yet comfortably, about the user&#39;s leg adjacent the knee, but yet provide the adequate support so as to prevent relative movement of the knee brace with respect to the knee so that the brace provides its desired function. It would be advantageous to provide a knee brace having, for example, a larger thigh engagement structure.  
       BRIEF SUMMARY  
       [0014]     The inventions described and claimed herein have various attributes and embodiments including, but not limited to, those set forth or described or referenced in this Brief Summary. The inventions described and claimed herein are not limited to or by the features or embodiments identified in this Brief Summary, which is not included for purposes of restriction or limitation.  
         [0015]     In one aspect the invention broadly provides a knee brace device having a substantially rigid support and an enlarged adaptable thigh pad providing a better grip on the leg of the user. The thigh pad is connected to rigid elements of the knee brace so as to be correctly aligned with the long axis of the user&#39;s femur. The thigh pad includes and x-shaped member which allows the knee brace to spread in leg flexion and narrow in leg extension.  
         [0016]     Further aspects of the invention will become apparent from the following detailed description, which is provided by way of example only. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0017]     Various other objects, features and advantages of the present invention will become readily apparent by reading the following description in conjunction with the drawings, which are shown by way of example only, wherein:  
         [0018]      FIG. 1  is a front elevation of a knee brace according to the present invention;  
         [0019]      FIG. 2  is a detailed view of an anterior thigh pad for the knee brace according to the present invention; and  
         [0020]      FIG. 3  is a front elevational view of an alternate embodiment of the knee brace according to the present invention. 
     
    
     DETAILED DESCRIPTION  
       [0021]     Referring now to the drawings in detail, wherein like reference characters refer to like elements, there is shown in  FIG. 1 a  knee brace  10  according the present invention. Although this invention will be described by way of example and with reference to various preferred embodiments, it is to be understood that modifications or improvements may be made thereto without departing from the scope or spirit of the invention. Various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications are included within the present invention.  
         [0022]     Referring to  FIG. 1 , the knee brace  10  is shown having a biomechanical support comprising a pair of substantially rigid upper  13  and lower  16  arms, which are joined together by a hinge assembly  19 . Connected to the rigid lower arms is a lower or tibial cuff pad  22  that, together with adjustable tibial strap  25 , secures the knee brace  10  to the users lower leg  28  below the knee  31 . A second tibial strap (not shown) may be attached to the lower arms  16  adjacent to the tibial cuff  22  to additionally secure the brace  10  in the area of the user&#39;s calf.  
         [0023]     Preferably, the knee brace  10  is constructed of a relatively strong yet lightweight fiber reinforced composite material. Pads and or liners are used on the interior portion of the brace to provide a comfortable feel against the user&#39;s leg. The hinge assembly  19  has a predetermined range of movement corresponding to the desired range of extension and flexion of the user&#39;s knee  31 .  
         [0024]     The upper arms  13  are secured to the users thigh (femur)  34  by an adaptable anterior thigh pad  37 . In this way the hinge assembly  19  is placed adjacent the axis of the user&#39;s knee joint, thereby allowing the knee brace  10  to substantially mimic the bending of the user&#39;s knee  31  as the user goes about his or her otherwise normal activities. The anterior thigh pad  37  is designed to absorb the soft tissue profile change of the thigh, while the brace  10  still exerts a consistent skeletal force for proper support of the knee during normal knee  31  movements. One or more additional straps (not shown) may be used to secure the upper arms  13  to the posterior of the users thigh, in a manner well known in the art.  
         [0025]     As indicated in  FIGS. 1 and 2 , the anterior thigh pad  37  may be attached to the upper arms  13  at four (4) basic attachment points, labeled A, B, C and D. The design of the anterior thigh pad allows the relative position of points A, B, C and D to remain constant, whereas the area in between adapts to underlying soft tissue movement during normal knee motion. The anterior thigh pad  37  is attached to points A, B, C and D are joined by four (4) length-adjustable straps  40 . For each of the straps  40  one end  43  is fixed to one of the upper arms  13  while an opposite end passes through a corresponding buckle  46  in the anterior thigh pad and is adjustably secured to itself.  
         [0026]     In one most preferred embodiment, it would be advantageous to be able to vary the position of points C and D. For a taller person with a longer thigh  34  it would be beneficial to lower the attachment points C and D, or move them closer to the knee  31 . This is achieved by moving the strap attachment point to one of several other predetermined positions  49  on the rigid upper arms  13 . A pivot point  52  enables the variable positioning of the straps with respect to points C and D. The pivot point may comprise a rivet or plastic clip.  
         [0027]     Preferably the anterior thigh pad  37  is generally constructed of a rigid yet lightweight fiber reinforced composite material similar to that of the upper and lower arms. While the x-crossing members C-B and A-D are integrally formed with their corresponding buckles  46  at points C and D, the upper horizontal connection  55  between points A-B may be accomplished by overmoulding a more resilient thermoplastic resin material. This material in the upper horizontal section  55  of the anterior thigh pad  37  allows for a degree of elasticity and flexibility to accommodate muscle expansion during normal leg movements. However, the rigidity of the crossing members maintains the fixed length of these diagonal sections.  
         [0028]     The anterior thigh pad  37  adapts to the underlying soft tissue movement of the thigh during knee motion. This anterior thigh pad  37  allows the knee brace  10  to spread in leg flexion and narrow in leg extension, just as the leg muscles normally do. This allows the quadriceps and hamstrings of the users upper leg to “fire” normally while the knee brace  10  maintains a predictable and constant force on the skeleton.  FIG. 3  shows an alternative embodiment of the thigh pad.  
         [0029]     The knee brace of the present invention thus provides a three-point fixation centered at the knee that may be used to achieve the desired control over tibial movement with respect to the femur for proper knee bracing. The knee brace  10  provides a solid grip above the knee, at the knee and below the knee to provide the necessary control of the weakened knee joint. Because the anterior thigh pad  37  for the knee brace  10  of the present invention adapts to the soft tissue movement, distal migration of the knee brace is eliminated. Hence the hinge  19  remains centered at the knee joint. Maintaining the hinge  19  in the proper relation with the knee  31  is desired to “push” the tibia into a slight valgus deformity, or less frequently, a slight varus deformity to counteract anterior translocation of the tibia with respect to the femur which can occur with ligament instability. A condylar pad  58  on the interior portion of each hinge  19  comfortably supports the knee joint in the lateral direction.  
         [0030]     The adaptability of the anterior thigh pad  37  for the knee brace  10  of the present invention provides significant advantages over conventional bracing systems. In any population sample there will be a relatively small range of knee width and tibial size, but the range of thigh shape is much greater, and highly variable for any given knee and calf anatomical dimension. For any given individual the thigh shape to which a brace is to be applied will vary with degree of obesity or muscle definition, which tends to vary with exercise. It is therefore preferable to be able to have an adjustable soft or semi-rigid element linking the rigid elements on either side of the thigh. This component must allow for adjustment in several anatomical planes.  
         [0031]     The objective of the resilient upper horizontal connection  55  across the top of the anterior thigh pad  37  is to hold the rigid thigh elements in line with the femur and prevent hyperextension (over-straightening) of the knee. The objective of the crossing members is to grip the quadriceps and resist twisting of the knee brace  10 , which is important for resistance of certain distorting forces applied to the knee (varus/valgus/rotation).  
         [0032]     An objective of the present invention is to provide an adjustable thigh section linking the rigid elements on either side of the thigh, and particularly one that is adjustable in several planes so that a rigid knee brace can be accurately fitted to, and intermittently adjusted for, any anterior thigh anatomical profile. This is beneficial because it allows accurate fitting to a wide range of profiles that can vary over time in any one individual. The human thigh profile is a complicated shape that moves during a gait cycle in a variable way, determined by the relative size of the components of the quadriceps mechanism. The quadriceps is made up of component muscles that vary with activity level in any individual, so changes in overall quadriceps profile are frequent.  
         [0033]     Accurate adjustment of the individual straps for the anterior thigh pad  37  of the present knee brace  10  will not only provide an accurate and comfortable fit, but it will ensure that the individual anterior thigh pad  37  is appropriately tensioned to resist distorting forces or movements, and therefore provide a predictable skeletal force. Irrespective of the shape of the tibial component, an anterior thigh component, adjustable in several dimensions, is beneficial in terms of fitting any individual thigh, because it is more adaptive to soft tissue profile. The result is that the knee brace  10  of the present invention is more positionally stable, and therefore exerts a more predictable and constant force on the underlying skeleton, which is the objective of knee bracing.  
         [0034]     The instructions for fitting and adjusting the knee brace  10  of the present invention can be easily followed by a user, with or without prior instruction by any health care provider. First, the condylar pads  58  are positioned on each hinge  19  at the knee joint line on either side of the knee. The tibial cuff  22  is generally fitted to the lower leg  28  and the tibial strap(s)  25  tensioned for a firm but not tight fit. The upper arms  13  are thereby positioned on either side of the thigh  34 . These should lie in the mid-medial and mid-lateral line parallel to the long axis of the femur. The individual straps  40  of the anterior thigh pad  37  should generally be in a loosened state. The straps connecting the upper horizontal connection between points A and B may be adjusted so that in full extension the upper straps are tight across the thigh  34  and the rigid upper arms  13  lie parallel to the femur in the mid-medial and lateral lines, respectively. With the knee  31  flexed a predetermined amount, preferably at about 30 degrees, the straps connecting points C and D are individually adjusted to give a firm grip across the thigh  34 . Preferably, these crossing straps are equally tensioned. When the knee is  31  then straightened, the crossing straps will be in the relaxed state and the horizontal strap will be in a tightened state.  
         [0035]     Preferably the knee brace of the present invention provides various pads and liners between the rigid elements and the user&#39;s leg, as is conventional with braces in general. Also, a protective cuff or pad may be positioned over the anterior thigh pad  37  to prevent unintentional adjustment of the buckles  49 . Such a pad may be attached to the rigid upper arms  13  in any conventional manner, such as, by way of example, with hook and loop fasteners (Velcro).  
         [0036]     As can be seen from the foregoing, the invention provides a knee brace that includes functional elements that provides a number of different advantages. One advantage is grip, in terms of gripping the soft tissue of the user in to enable the brace to function effectively, and also to be able to provide skeletal grip in virtually all knee positions.  
         [0037]     Where in the foregoing description, reference has been made to specific components or integers of the invention having known equivalents then such equivalents are herein incorporated as if individually set forth. While specific embodiments of the invention have been shown in the drawings and described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives would be developed in light of the overall teachings of the disclosure. Accordingly, the particular arrangements disclosed herein are meant to be illustrative only and not limiting as to the scope of the invention, which is to be given the full breadth of the appended claims and in any and all equivalents thereof.