Patent Publication Number: US-9895577-B2

Title: Knee rehabilitation assistance device

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation application of U.S. patent application Ser. No. 14/179,370 filed on Feb. 12, 2014. U.S. patent application Ser. No. 14/179,370 claims priority to U.S. Provisional Application 61/763,831, filed on Feb. 12, 2013. The entire disclosures contained in U.S. Provisional Application 61/763,831 and U.S. patent application Ser. No. 14/179,370 including the attachments thereto, are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present application is generally related to devices with which a person may rehabilitate muscles and ligaments attendant to extending and flexing of the knee joint. More specifically, the present application relates generally to devices with which a person may undertake therapeutic exercise for rehabilitation, following knee replacement, knee surgery, or knee injury. 
     BACKGROUND OF THE INVENTION 
     Axiomatic in the field of physical therapy is that early implementation of a rehabilitation program, comprised of motion and strengthening exercises, is essential to realizing optimal results for regaining functional recovery following surgery or injury to the knee joint. 
     For patients who have undergone surgery for knee replacement or repair, medical care professionals will routinely recommend protocols designed to enable the patient to control and manage pain and swelling, increase range of motion, and endure progressive weight-bearing, in accordance with the patient&#39;s strength level, healing progress, and pain tolerance. Many traditional knee rehabilitation exercises involve hands-on manipulation by a physical therapist, as well as exercises performed by the patient without the assistance of mechanical devices or other individuals. 
     The object of the present device is, generally, to provide an apparatus to facilitate the attainment of rehabilitation goals for patients or users recovering from knee repair or replacement surgery, by providing an easily portable knee exercise device with which the patient or user, while lying comfortably on a floor or other flat, horizontal surface, can position and maintain his or her leg in an approximately vertical position relative to the user&#39;s upper torso in order to situate the targeted knee above the user&#39;s heart to alleviate knee swelling; and, which the user may use when he or she is at a rehabilitation phase that is centered primarily on passive range of motion and management of swelling, as well as when the user progresses to a stage in the rehabilitation process where he or she may focus more directly on developing strength and functional independence. 
     RELEVANT ART 
     There are patented inventions which may be of some use for rehabilitating a knee that has been injured or which has undergone surgery. For example, U.S. Pat. No. 5,074,549 to Harvey discloses a frame structure with a horizontal bar which enables the leg to be flexed such that the leg is approximately vertical. Thereafter, weights or other pressure devices may be used to navigate the lower leg so as to exercise the knee joint. However, Harvey requires the user to grip the device and apply a pulling force on the invention itself, in order for the user to situate his or her upper thigh in certain positions. Also, Harvey does not appear designed for truly passive exercising of the user&#39;s knee through extension or flexion. 
     Another invention known to the inventor is the knee rehabilitation device of Mason et al., U.S. Pat. No. 5,509,894. Mason, et al. involves suspension of the user&#39;s leg using a bar, located above the leg, to which straps are attached. The user&#39;s leg is strapped just above the knee, and also around the ankle. However, Mason et al. does not place the user&#39;s leg in a truly perpendicular position, relative to the surface on which it is placed, and thus is relatively limited in the ranges through which the user may move his or her leg. 
     An exercise device detailed in expired U.S. Pat. No. 3,717,144 to Bimler describes a device wherein both the upper leg and lower leg are supported by sections which pivot to allow the knee to bend. The upper and lower leg remain supported during movement. The Bimler device appears to allow no more than approximately 90 degrees of bend in the knee during flexion, which may diminish the invention&#39;s utility for users who are have progressed to a point in the rehabilitation process of being able to tolerate a fuller range of knee bend. 
     Another exercise device is U.S. Pat. No. 4,844,454 to Rogers. This device features a hinged platform to which the upper leg and lower leg are strapped. The hinge action of the platform is facilitated by manual manipulation of a handle attached to the platform. The Rogers device appears to work the user&#39;s leg from and between an approximately extended leg position, to a leg position where the knee is flexed to approximately 90 degrees. Thus, Rogers provides a relatively limited range of motion during exercise. 
     A knee exercise device by Brooks is described in U.S. Pat. No. 4,784,121. The user of this device sits on a plate which is placed in a chair. The plate is attached to pivotally mounted levers and linkage whereby the user may manually control resistance when lowering or extending the leg. The knee can be flexed so that the leg is approximately straight. However, like Rogers and Bimler, the range of motion for bending the knee is limited to approximately 90 degrees. Also, the knee is positioned below the user&#39;s heart, and thus may have limited utility for the controlling of swelling that may be present in the user&#39;s knee. 
     Therefore, while there are currently inventions which appear to be of use for knee rehabilitation while offering such advantages as being portable, comfortable, safe to use, and easily adaptable for users of all body types, there does not appear to be any one device that offers these advantages while allowing the user to exercise the knee in a position which helps to reduce swelling, while also offering substantial versatility with the degree of range-of-motion and resistance exercising that the user may undertake in accordance with the strength, pain, and tissue-healing constraints with which the user may be coping at various phases of the rehabilitation process. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     The embodiment of the present device is comprised of a rehabilitation assistance device for use in strengthening and stretching muscles, tendons, and ligaments attendant to movement of a human knee following surgery for knee repair or replacement, or for rehabilitation of injuries to or around the knee. The device allows the post-operative user to lie down comfortably on a flat, horizontal surface, and brace the leg which is being rehabilitated so that the user&#39;s upper thigh is approximately vertical in relation to the user&#39;s upper torso. 
     An embodiment of the present device is comprised of an elongate section of straight, hollow, approximately cylindrical pipe. Attached proximal to both ends of the elongate section of pipe is a section of straight, hollow, approximately cylindrical pipe extending approximately perpendicularly from the elongate section of pipe, to form a “T” shape at both ends of the elongate section of pipe. The “T” sections at either end of the elongate section of pipe are approximately parallel to one another. 
     An approximately cylindrical cross-piece of pipe is attached at the approximate center part of the elongate section of pipe, so that the central part of the cross-piece intersects the central portion of the elongate section of pipe, and so that the cross-piece is approximately parallel to the sections of pipe that form a “T” shape at either end of the length of pipe. The elongate section of pipe, “T” shape sections of pipe, and cross-piece of pipe are situated approximately horizontal with the flat surface on which the user lies supine when using the device. 
     Attached proximal to both ends of the cross-piece is a straight section of pipe that attaches proximally to and extends vertically from each end of the cross-piece. Each of these two vertical sections of pipe is approximately perpendicular in relation to the elongate section of pipe, “T” sections of pipe, and cross-piece of pipe. The two vertical sections of pipe are approximately parallel to one another. In some embodiments, a stabilizing bar connects to and spans the distance between each vertical section of pipe, to more firmly maintain the two vertical sections of pipe in a parallel position to one another. 
     In an embodiment of the present device, the elongate section of pipe, “T” shape sections of pipe, cross-piece of pipe, vertical sections of pipe, and stabilizing bar comprise the framework components of the present device. In some embodiments, the framework components are comprised of polyvinyl chloride (PVC) pipe. In some embodiments, the framework components of the present device may be comprised of any solid, durable, lightweight material. 
     In some embodiments, the assembled framework components are secured together with one another by angled couplers comprised of light materials similar or identical to the materials of which the framework components are comprised. In some embodiments, the angled couplers are bound to the framework components using appropriate adhesives. 
     In an embodiment of the present device, a leg support bar made of lightweight metal, PVC pipe, or other durable, lightweight material is attached to a mount located intermediately along the elongate section of pipe. In some embodiments, the mount projects vertically from the elongate section of pipe at a point which is approximately midway between the cross-piece of pipe and one of the sections of pipe that firms a “T” at one end of the length of pipe. When attached, the leg support bar extends upward from the elongate section of pipe. In some embodiments, the mount connects proximally to the lower end of the leg support bar in a manner that forms an axis along which the leg support bar may be selectively adjusted to move clockwise or counterclockwise from approximately zero degrees to approximately one hundred and eighty degrees along a generally vertical plane. 
     In some embodiments, an arcuate brace is attached proximal to the upper end of the leg support bar, distal to the elongate section of pipe. The user gets into position for using the present device by lying flat on his or her back, against the floor or other flat surface upon which the present device has been placed. The user is properly positioned when he or she is lying nearest to the end of the device where the leg support bar is located, with the upper thigh of the patient&#39;s “targeted” leg raised to approximately ninety degrees in relation to the user&#39;s upper torso. The back of the user&#39;s upper thigh fits within the concavity of the arcuate brace proximal to, but just above, the knee joint. The user&#39;s upper thigh is thusly maintained in an approximately vertical position to enable the user to bend and flex the knee in accordance with the user&#39;s capabilities and rehabilitation objectives. 
     In some embodiments of the present device, one or more elastic bands may stretch along an approximately horizontal plane from one vertical section of pipe to the other vertical section of pipe, to serve as a way to limit the range of flexion for the user&#39;s leg, in accordance with the user&#39;s pain tolerance and/or range of motion capabilities and/or rehabilitation directives. In such embodiments, the vertical sections are telescoping to allow selective adjustment of the height at which the band is positioned relative to the flat surface on which the user is resting. At the selected height, the user&#39;s leg makes contact with the band at some point during flexion, thus selectively limiting the user&#39;s flexion range of motion. 
     In some embodiments, the user may fit his or her ankle into an ankle strap that is attached to a rope of nylon or other weather-resistant material. In such embodiments, a pulley system allows the user to do quadriceps strengthening exercising by applying a desired amount of pulling force to a handle attached to the rope at the end opposite of where the ankle strap is attached. This pulling action facilitates upper thigh and knee joint strengthening by exerting reciprocal resistance against extension of the user&#39;s leg, and/or provides downward-pulling force to the user&#39;s lower leg as may be appropriate where the user has a stiff knee joint in need of passive range-of-motion exercising. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Additional utility and features of this device will become more fully apparent to those skilled in the art by reference to the following drawings, which illustrate some of the primary features of preferred embodiments. 
         FIG. 1  is a perspective view of an embodiment of the knee rehabilitation assistance device, shown with accessories. 
         FIG. 2  is a perspective view of an embodiment of the knee rehabilitation assistance device, shown without accessories. 
         FIG. 3  is a perspective view of an alternative embodiment of the device, showing a user&#39;s leg positioned for using the device. 
         FIG. 4  is a perspective view of the device shown in  FIG. 3 , showing a user going through manually assisted leg flexion. 
         FIG. 5  is a back perspective view of the device shown in  FIG. 1 . 
         FIG. 6  is a perspective view of the embodiment shown in  FIG. 2 , showing a user going through active range-of-motion exercise. 
         FIG. 7  is a front perspective view of the device shown in  FIG. 3 . 
         FIG. 8  is a fragmentary perspective view of a portion of the present device, with a mount projecting therefrom. 
         FIG. 9  is a fragmentary perspective view of a portion of the present device. 
         FIG. 10  is a fragmentary side view of a portion of the present device. 
         FIG. 11  is an exploded fragmentary side view of some components of the present device. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION 
       FIG. 1  is a perspective view of an embodiment of knee rehabilitation assistance device  10 . Elongated section of pipe  11  forms a central beam. First T section  12  is connected to one end of elongate section of pipe  11 , and second T section  13  is connected to the opposite end of elongate section of pipe  11 . First T section  12  and second T section  13  form a “T” shape at either end of elongate section of pipe  11 , and are approximately parallel to one another. Connected at approximately the center of elongate section of pipe  11  is cross-piece  14 . Cross-piece  14  is approximately parallel to first T section  12  and second T section  13 . Alternatively to cross-piece  14 , two cross members may extend laterally from elongate section of pipe  11  at the location of cross-piece  14 . Together, elongate section of pipe  11  and cross-piece  14  combine to form horizontal component  51 , which provides a base for knee rehabilitation assistance device  10 . 
       FIG. 2  is another perspective view of an embodiment of knee rehabilitation assistance device  10 , showing first vertical section, or riser,  15  attached along one end of cross-piece  14 , and second vertical section, or riser,  16  attached along the opposite end of cross-piece  14 . First vertical section  15  and second vertical section  16  are approximately parallel to one another, are approximately equal in length to one another, and are approximately perpendicular to cross-piece  14 . Stabilizing section  17  attaches to first vertical section  15  and second vertical section  16  to act as a stabilizer and help maintain first vertical section  15  and second vertical section  16  in their approximately parallel positions to one another. 
       FIG. 2  also shows elongate leg support bar  18  attached to mount  36 . Referring to  FIG. 8 , in some embodiments, mount  36  vertically projects from a point intermediately along the length of elongate section  11  at a point approximately mid-way between first T section  12  and cross-piece  14 . Leg support bar  18  pivotally attaches to mount  36  proximal to the lower end of leg support bar  18 . Leg support bar  18  is adjustably rotatable in a clockwise or counterclockwise manner along first axis  19 , and is movable along a generally vertical plane from and between a position of approximately zero degrees to approximately 180 degrees in relation to elongate section  11 . In some embodiments, leg support bar  18  fits slidably into a leg support bar sleeve (not shown) which may be located intermediately along the length of leg support bar  18 . In such embodiments, the length of leg support bar  18  can be adjusted via a telescoping action, to fit to the leg length requirements of the individual user. 
     Referring again to  FIG. 2 , brace  20  attaches proximal to the upper end of leg support bar  18  so that brace  20  is distal to elongate section  11 . Brace  20  is connected to leg support bar  18  in a manner which forms second axis  21 . Brace  20  may be pivotally adjusted upward or downward along second axis  21 , as needed to accommodate the comfort requirements of the user. Mount  36 , leg support bar  18 , and brace  20  combine to form leg positioning element  52  which maintains a user&#39;s upper leg, or thigh, in the desired position. 
     In  FIG. 3 , a user is positioned to use knee rehabilitation assistance device  10 . The back of the user&#39;s upper thigh is positioned in the concavity of brace  20 . To better enable the user&#39;s leg to move through its fullest possible range of motion, the user should position his or her leg against brace  20  in proximity to but above the knee, so that brace  20  rests against the bottom of the user&#39;s leg biceps. In the embodiment shown in  FIG. 3 , the back of the user&#39;s lower leg rests against elastic band  22 . One end of band  22  is tethered to first vertical section  15 , and the other end of band  22  is tethered to second vertical section  16 . The ends of band  22  may be tethered along the length of first and second vertical sections  15 ,  16  to span the distance between first and second vertical sections  15 ,  16  along a generally horizontal plane, at a selected height which may be chosen by the user according to the desired range within which the user desires to limit his or her leg flexion. 
       FIG. 4  shows a user employing the device for manually-assisted range-of-motion exercise. A manual exerciser attaches to the user&#39;s lower leg at one end and it&#39;s other end reaches to a location where the user may grasp the manual exerciser. The embodiment in  FIG. 4  shows ankle strap  23  secured to the user&#39;s ankle. Rope  24  comprised of nylon or other weather-resistant material has handle  27  attached proximal to one of its ends. Ankle strap  23  is attached proximal to the end of rope  24  opposite that to which handle  27  attaches, and is secured to the user&#39;s ankle.  FIG. 4  shows the user grasping handle  27  and exerting a pulling force along a generally horizontal plane. Pulling on handle  27  creates tension in rope  24 . First pulley  26  guides rope  24  to exert a reciprocal downward pulling force on the user&#39;s lower leg, so that the heel of the user&#39;s foot moves along a generally vertical plane toward the user&#39;s buttocks. The greater the pulling force exerted on handle  27 , the greater the reciprocal pulling force upon the user&#39;s lower leg. Second pulley  25  is shown attached intermediately along the length of cross-piece  14  to accommodate a user employing his or her right hand to grip and pull on handle  27 . 
       FIG. 5  is a perspective view of an embodiment of knee rehabilitation assistance device  10 , with the back of the device in the foreground. As shown in  FIG. 5 , second pulley  25  may be repositioned to attach along alternate second pulley location  30 , to accommodate use of the user&#39;s left hand to grip and pull handle  27 .  FIG. 5  also provides a rear view of elongate section of pipe  11  and cross-piece  14  combining to form horizontal component  51  and provide a base for knee rehabilitation assistance device  10  (and see  FIG. 7 ). 
     The embodiment shown in  FIG. 6  is a perspective view of the embodiment shown in  FIG. 2 . In  FIG. 6 , the user is undertaking active range-of-motion exercise by extending and flexing his or her leg, with the back of the user&#39;s upper thigh positioned against brace  20 . The user is shown moving his or her lower leg from a position approximating full leg extension, to a position approximating full flexion. The user may choose to use ankle weights if he or she desires, to add strength-building resistance to the exercise. Referring again to  FIG. 4 , the user may also undertake strength-building exercise by attaching ankle strap  23  to his or her ankle, and exerting tension on leash  24  by pulling on handle  27 . 
       FIG. 7  is a perspective view of an embodiment of knee rehabilitation assistance device  10 , with the back of device  10  shown at the forefront. First vertical section  15  and second vertical section  16  are each comprised of inner slide cylinder  33  and outer sleeve  34 . Inner slide cylinder  33  fits into outer sleeve  34 , and can be easily manipulated to telescopically slide in and out of outer sleeve  34 . 
     Both first vertical section  15  and second vertical section  16  each have a plurality of apertures  29  drilled through them. After first vertical section  15  and second vertical section  16  are telescopically adjusted to a desired length, pin  28  fits into aperture  29  which is nearest to mouth  35  of outer sleeve  34  of first vertical section  15  and second vertical section  16 . Pin  28  catches flush against mouth  35  of outer sleeve  34  to maintain first vertical section  15  and second vertical section  16  at a selected height. Band  22  is shown tethered to and spanning the distance between first and second vertical sections  15 ,  16 , along a generally horizontal plane. By telescopically adjusting the lengths of first and second vertical sections  15 ,  16 , band  22  may be positioned at a selected height in accordance with the range within which the user wishes the band  22  to limit the degree of leg flexion. This feature may be useful in situations where, for example, the user is at a rehabilitation stage where pain or stiffness makes it desirable to limit the range of leg flexion. 
       FIG. 8  is a fragmentary perspective view of a portion of elongate section  11 . Mount  36  is shown projecting vertically from a position intermediately along the length of elongate section  11 . Mount  36  has annular socket  31  comprised of a plurality of tapered, equally-spaced first teeth  32  situated circumferentially along socket  31 . 
       FIG. 9  is a fragmentary perspective view of a portion of the present device. Proximal to the lower end of elongate leg support bar  18  is an annular spline  40  comprised of a plurality of tapered, equally-spaced second teeth  37  situated circumferentially along spline  40 . Second teeth  37  are complimentarily sized, configured, and positioned to interlockably engage with first teeth  32 . Fastening components are used to releasably couple said first teeth  32  and said second teeth  37  to allow leg support bar  18  to adjustably rotate along a vertical plane. Fastening components are comprised of an elongate first bolt  38  having external, spiral threads. First bolt  38  projects radially from socket  31 , and is configured to fit through a similarly-sized aperture  41  traversing radially of spline  40 . A first nut  39  having a spiral-threaded inner circumference fastens to first bolt  38  to adjustably fasten leg support bar  18  to mount  36  at a selected angle. 
       FIG. 10  is a fragmentary side view of a portion of the present device. First axis  19  along which support bar  18  adjustably rotates is generally parallel to the pivot axis of the user&#39;s knee joint, so that leg support bar  18  is rotatable clockwise and counterclockwise along a generally vertical plane. The specific manner in which mount  36  attaches proximal to the lower end of leg support bar  18  is not critical so long as leg support bar  18  may be firmly, rotatably secured at a selected angle. Leg support bar  18  and brace  20  are components of leg positioning element  52 . Brace  20  can also be angularly adjusted and secured at a selected angle with respect to leg support bar  18 . 
       FIG. 11  is an exploded fragmentary side view of a portion of the present device. A portion of the upper end of support bar  18  is shown. A smooth, arcuate brace  20  pivotally mounts proximal to the upper end of support bar  18 . In an embodiment, brace  20  has a first yoke located along its apex, said first yoke having first yoke aperture  44 . The upper end of support bar  18  has a second yoke including a second yoke aperture  45  of similar size to that of first aperture  44 . An externally-threaded elongate second bolt  42  bolt fits through both apertures. A second nut  43  having threads along an inner circumference fastens to second bolt  42 , to engage brace with upper end at a selected angle. Second nut  43  can be loosened from second bolt  42  to allow brace  20  to selectively pivot upward or downward along a vertical plane, to a position suitable to the user&#39;s comfort requirements. 
     The specific manner in which brace  20  is secured proximal to the upper end of support bar  18  is not critical so long as brace  20  may be firmly, pivotally secured at a selected angle. As the user lies supine on a flat surface in position to use the device, the open end of brace  20  faces toward the user. The back of the upper thigh of the leg being rehabilitated by said user fits into the concavity of brace  20 , and with brace  20  proximal to the knee joint at a location just above the crease of the knee joint. Thus, the user&#39;s upper thigh is maintained at a selected vertical angle, thereby enabling the lower leg to be selectively raised and lowered relative to said upper thigh. To optimize range of motion and minimize knee joint swelling, the selected angle of the user&#39;s upper thigh may be approximately ninety degrees relative to the horizontal surface upon which the user is lying during exercise. 
     It is to be understood that the embodiments and claims herein are not limited in application to the details of construction and arrangement of the components set forth in the description and illustrated in the drawings. Rather, the description and the drawings provide examples of the embodiments envisioned, but the claims are not limited to any particular embodiment or a preferred embodiment disclosed and/or identified in the specification. The drawing figures are for illustrative purposes only, and merely provide practical examples of the invention disclosed herein. Therefore, the drawing figures should not be viewed as restricting the scope of the claims to what is depicted. 
     The embodiments and claims herein are further capable of other embodiments and of being practiced and carried out in various ways, including various combinations and sub-combinations of the features described above but that may not have been explicitly disclosed in specific combinations and sub-combinations. Accordingly, those skilled in the art will appreciate that the conception upon which the embodiments and claims are based may be readily utilized as a basis for the design of other structures, methods, and systems. In addition, it is to be understood that the phraseology and terminology employed herein are for the purposes of description and should not be regarded as limiting the claims.