Patent Publication Number: US-6217484-B1

Title: Rehabilitation apparatus

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to apparatus for aiding in the rehabilitation of patients with weight bearing restrictions on one or both legs and more particularly to apparatus including a pair of raised platforms, one of which is stable and the other vertically movable in response to a downward force applied on the upper surface. 
     In the rehabilitation of patients having weight bearing restrictions on one or both legs, the apparatus conventionally used is the parallel bar structure having a fixed platform on which the patient may walk. The problem with this is that if, for example, there is a maximum tolerable load that should be placed on a leg currently there is no way by which the patient, the therapist or doctor can control the load and further injury may occur. Thus, very conservative therapy may result and this could prolong the rehabilitation process. In some cases, a leg weight exercising machine of the type wherein the patient sits and pushes his or her feet on pedals connected to weights by cables may be used. However, such apparatus is not completely effective since it does not promote the natural gait or stride of the patient. A search of the prior art did not locate anything believed to be relevant, the most relevant reference being U.S. Pat. No. 5,112,045 which shows a platform mounted on a pivot permitting walking motion or balancing by the user for purposes of kinesthetic diagnosis and rehabilitation. 
     SUMMARY OF THE INVENTION 
     Consequently, it is a primary object of the present invention to provide apparatus for aiding in the rehabilitation of patients having weight bearing restrictions on one or both legs. 
     It is another object of the present invention to provide apparatus including at least a pair of raised platforms on which a patient undergoing rehabilitation may walk, one foot being on each platform, at least one of the platforms being movable vertically and having a selected force applied upwardly. 
     It is a further object of the present invention to provide apparatus for aiding in the rehabilitation of patients with weight bearing restrictions on either one or both legs, the apparatus including two pairs of elongated horizontal movable platforms, one platform of each pair being mounted for movement in a vertical plane, each movable platform being pushed upwardly by selected predetermined force and being pushed in a downward direction by a foot of the patient as the patient strides on either both movable platforms or one of the movable platforms and a fixed platform adjacent to each movable platform. 
     Accordingly, the present invention provides apparatus for use in rehabilitation of a patient with weight bearing restrictions on one or both legs, the apparatus including a first vertically movable horizontally elongated platform and a second platform which may be either vertically movable or fixed, the movable platform being connected to a mechanism which applies an upwardly directed preselected force thereto and as the patient walks with one foot on the movable platform and the other foot on either a similarly movable platform or a stable platform, the movable platform will descend if the patient places too great a weight load on the platform. 
     Preferably there are two side-by-side movable platforms and a fixed platform on the other side of each movable platform so that patients having weakness in either both legs or only one leg may walk in either direction. If both legs are involved in the rehabilitation then both movable platforms have individually preselected upward forces applied thereto. 
     The apparatus further includes conventional parallel bar handrails, there being one handrail associated with each pair of platforms preferably supported by the fixed platforms where such fixed platforms are utilized. 
     The mechanism which mounts each movable platform provides a fulcrum about which the platform may move, a weight being placed on one side of the fulcrum and the platform and thus the foot of the patient being on the other side. Preferably, the weight may be moved relatively to the fulcrum. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The particular features and advantages of the invention as well as other objects will become apparent from the following description taken in connection with the accompanying drawings, in which: 
     FIG. 1 is a perspective view illustrating rehabilitation apparatus constructed in accordance with the principles of the present invention; 
     FIG. 2 is a cross sectional view taken transversely through the rehabilitation apparatus depicting conceptionally the principles of the present invention in regard to a first embodiment, and illustrating the moving elements in two positions; 
     FIG. 3 is a view similar to FIG. 2, but taken transversely through the apparatus of FIG. 1 illustrating the preferred form of the present invention; 
     FIG. 4 is a top plan view of the apparatus illustrated in FIG. 1, with parts thereof removed to illustrate the platform moving mechanism; and 
     FIG. 5 is a view similar to FIG. 4, but with parts removed to illustrate the platform locking mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings, FIG. 1 illustrates rehabilitation apparatus  10  in the form of a walkway  12  constructed using principles of the present invention. The walkway comprises first and second fixed ramps  14 ,  16  at respective ends thereof, the major portion of the ramps being inclined, and having a plurality of platforms preferably two pair of two platforms each such that there may be four platforms extending longitudinally therebetween. As will be understood, a rehabilitation apparatus incorporating only one pair of platforms may be constructed without departing from the principles of the present invention. 
     As illustrated in FIG. 2, the platforms  18  and  24  are fixed platforms secured to a plurality of upstanding rails  26 ,  28  respectively on corresponding sides of the walkway, the rails  26 ,  28  having a respective handrail  30 ,  32  extending longitudinally secured thereto above the platforms as best illustrated in FIG.  1 . Each of the platforms  20 ,  22  is a movable platform being carried by a structure including a plurality of respective levers  34 ,  36  pivotally journaled on the rails  26 ,  28  at the respective side in the vicinity of the platforms. Each lever  34 ,  36  and the movable platfonn driving system is identical and reference to that associated with the platform  20  and its lever  34  only will be described. 
     The movable platform  20  may be secured to a driver including an upstanding support arm  38  spaced from the journal or pivot bearing  40 , while a weight mass or stack of weights  42  may be mounted on a second upstanding arm  44  spaced from the journal  40  and from the platform  20 . The weight mass or stack  42  is adjustable by adding or subtracting weights  46 ,  48 . The greater the amount of weight on the stack  42  the greater the movement placed on the lever and thus the greater the upward force placed on the platform  20 . The upward movement of the platform  20  is limited by a limit block  50  while the downward movement is limited by another limit block  52 . Thus, a patient may stride on the platforms  18  and  20 , with a foot on each holding the handrail  30  and the force on the leg which is on the platform  20  may be controlled. If the patient has a weight bearing restriction on the leg which is on the platform  20 , the weight stack  42  can be selected to apply the maximum force equal to that of the weight restraint onto the platform  20  and thus the leg thereon. The force applied will, of course, depend upon the weight in the stack and the length of each leg of the lever from the journal. This, however, is simple mechanics and need not be further explained. Then if the patient applies more weight to the leg on the movable platform  20 , the platform will begin to descend and thereby remind the patient to apply less weight or force. 
     A patient with a weight bearing restriction on both legs may stride on the two movable platforms  20  and  22 , holding both handrails  30 ,  32 , the weight stack associated with each being selected according to the weight restriction on each leg. 
     One of the limitations of the single embodiment of the invention illustrated in FIG. 2 is that the movable platforms  20 ,  22  while moving vertically do not move in a vertical plane, i.e., they move in an arc. Thus, the preferred embodiment of the invention, which is illustrated in regard to FIGS. 3 through 5, overcomes this shortcoming. Thus, as illustrated in regard to these figures, the movable platforms  20  and  22  are secured to respective rods  60 ,  62 , both rods being constrained to move in a vertical plane by guide housings  64 ,  66  carried by upstanding posts  68  intermediate the rod  60 ,  62  supported on cross members  70  forming part of the frame of the apparatus. The guide housings  64 ,  66  each mount linear bearings in which the rods  60 ,  62  travel in a vertical plane. As illustrated in FIG. 4, there may be five such pairs of rods  60 ,  62  for a walkway having platforms of approximately 12 to 15 feet. Moreover, there are a plurality of levers  134  and  136 , preferably two corresponding to each rod  60  and  62 , one on each side of a rail, respectively mounted on journal shafts  140 ,  141  extending longitudinally at each respective side. A weight stack  142 ,  143  is mounted about a spindle secured to a block  144 ,  145  attached to a plate  146 ,  147  through which an adjustment member such as the heads  206 , 208  of threaded rods  148 , 149 , the threaded rods  148 , 149  being threadedly received in blocks  200 , 201  and spaced plates  202 , 203  so that when the heads  206 , 208  are rotated, the respective weight stack  142 ,  143  move toward and away from the respective journal shaft  140 ,  141  to change the moment applied by the levers  134 ,  136 . Each lever carries a respective follower  150 ,  152  in the form of a small cylindrical rod which is trapped between a pair of U-shaped members  154 ,  156 ,  158 ,  160  secured to the rods  60 ,  62  respectively so that as the levers on one side move upwardly, the rods on that side do also, thereby moving or applying an upward force on the corresponding platforms, and vice versa when the platforms and the followers move downwardly. 
     Disposed beneath each guide housing  66  in a pair of spaced bearing blocks  180 ,  181 , and  182 ,  183  is a pair of spaced apart stop members  184 ,  185  in the form of rods which may move transversely within linear bearings in the bearing blocks. A plate  186 ,  187  is fastened to the respective stop member  184 ,  185 , the plate carrying a pin  196 ,  197  respectively. Each pin  196 ,  197  is located within a slot in a respective arm  188 ,  189 , there being five such arms on each side of the apparatus as illustrated in FIG.  5 . Extending through all of the arms  188  is a shaft  190  while a similar shaft  191  extends through all the arms  189  spaced from the respective plates  186 ,  187 . At each end of the walkway a manually graspable arm  192 ,  193  is secured at a respective side to the shaft  190 ,  191 . Each arm  188 ,  189  is mounted below the fixed platforms  18 ,  24  in a respective housing  194 ,  195  having a slot in a lower wall so that the levers  188  and  189  may be moved transversely as the respective arm  192 ,  193  is raised or lowered. As this occurs, the lower end of the respective lever slides the respective pins  196  or  197  and thus the respective stop member  184 ,  185  transversely. When the stop member is moved from out of the path with the respective rod  60 ,  62 , the movable platform may be moved vertically as illustrated in the right side of FIG.  3 . When the stop member is moved under the path of the respective rod  60 ,  62  as illustrated in the left side of FIG. 3, the moveable platform associated therewith is locked in the up position. The operation of the apparatus is the same as described in regard to the structure in FIG.  2 . However, the locking apparatus locking the movable platform in the upper position permits a starting condition when a patient is to walk on a fixed and a movable platform. The weights and moments are adjusted and the platform may then be unlocked, and the operation thereafter is the same as heretofore described in regard to FIG.  2 . 
     Numerous alterations of the structure herein disclosed will suggest themselves to those skilled in the art. However, it is to be understood that the present disclosure relates to the preferred embodiment of the invention which is for purposes of illustration only and not to be construed as a limitation of the invention. All such modifications which do not depart from the spirit of the invention are intended to be included within the scope of the appended claims.