Patent Publication Number: US-6666798-B2

Title: Therapeutic and rehabilitation apparatus

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Application No. 60/220,695 filed Jul. 21, 2000. 
    
    
     BACKGROUND OF INVENTION 
     1. Technical Field 
     The present invention generally relates to equipment used during rehabilitation of spinal and otherwise injured patients. More specifically, the present invention relates to an apparatus for assisting a patient to perform walking motion by connection of the apparatus between the legs of an injured patient and the legs of an attendant. 
     2. Background Information 
     Rehabilitation for victims of leg paralysis resulting from spinal cord injury requires using equipment that gives a paralyzed patient the opportunity to revitalize dormant muscles during relatively normal physical activity. Physical therapy for these patients has begun employing exercise assemblies such as treadmills that are normally associated with health and fitness clubs and the like. 
     In one application, a patient wears a body harness that supports the pelvic area and the upper torso while using a specially adapted treadmill. A strap extending from each shoulder to above the head of the patient attaches to an overhead support bar that is part of a support frame. A cable and pulley arrangement is activated to draw the shoulder straps up towards the support bar. This apparatus exerts an upwardly directed force on the patient in magnitude up to and including the point at which all weight has been counteracted and therefore removed from the patient&#39;s legs. Positional adjustment of the support frame allows the patient&#39;s feet to rest on the flat surface of the treadmill. 
     Once the treadmill begins to move the patient&#39;s feet contacting the flat surface are drawn along by the movement. In order to perform a walking motion, the patient traditionally has required assistance from one or more attendants. When performing such a therapeutic procedure, each attendant occupied a position by the side of the treadmill from which they could reach, lift and move the patient&#39;s legs in a motion that mimicked the walking process. A paraplegic required two attendants occupying positions on both sides of the treadmill in order to lift and move the patient&#39;s legs through the correct actions for walking. Alternatively, each attendant placed a foot of the patient in a forward position ahead of the patient&#39;s body. Normal, linear movement of the treadmill then displaced the foot to a position behind the patient. Completion of each attendant-assisted movement represented one stride for the patient. When a striding foot reached its rearmost position, the attendant on that side of the patient again lifted the foot from the flat surface of the treadmill and pulled it forward back to the starting position readied to allow the treadmill to effect another stride. The process of assisted walking of the suspended patient would continue giving the patient the opportunity to attempt to “learn” the waking process over again, while simultaneously strengthening their legs from the effort they are able to contribute during the therapy session. 
     The use of this technique for rehabilitation by reintroducing spinal injury sufferers to the familiar motion and pleasure of walking has been encouraging in terms of its results. For example, a hemiplegic, i.e., one who retains control over one leg, may perform a walking motion with assistance from only one attendant. The attendant repositions the injured leg while the patient still controls and moves his or her functioning leg. As indicated above, a paraplegic requires two attendants, i.e., one for each leg. Further, a quadriplegic requires even additional attendants for steadying the suspended body while the walking therapy is in progress. 
     A scarcity of skilled attendants limits the number of patients who may benefit from this type of rehabilitating treatment. This has led to attempts to develop mechanical devices that may assist with the walking process in the absence of an attendant. 
     One such device is a jointed leg brace that includes computer controlled actuators for moving sections of the brace in a way that simulates the gait of a walker. The brace is a complicated structure that must be strapped to a patient&#39;s hip, as well as outside the patient&#39;s leg in three locations—at the thigh, just above the calf and at the ankle. One or two braces may be used, depending upon the patient&#39;s condition. As before, the patient wears a harness for suspension by a frame with his or her feet resting on the flat surface of a treadmill. As the treadmill moves, the computer controlled brace performs strides by appropriately lifting and placing the patient&#39;s legs relative to the moving treadmill. 
     This use of computer controlled equipment presents at least two potential disadvantages. Firstly, there is the associated cost, which includes an expensive, computer assisted mechanical structure and its associated maintenance. Such a mechanical structure may be at least as expensive as the use of multiple rehabilitation attendants. Secondly, there is the possibility of computer or equipment malfunction that, in extreme cases, could lead to further injury of an unattended patient. 
     In view of the above described deficiencies associated with the use of known designs for assisted walking rehabilitation equipment and procedures, the present invention has been developed in order to alleviate these drawbacks and provide further benefits to the user. These enhancements and benefits are described in greater detail herein below with respect to several alternative embodiments of the present invention. 
     SUMMARY OF INVENTION 
     The present invention in its several disclosed embodiments alleviates the drawbacks described above with respect to conventionally designed rehabilitation equipment. It incorporates several additionally beneficial features that simplify therapy procedures and lower costs by reducing attendant-to-patient ratio. 
     Rehabilitation procedures according to the present invention require the use of equipment and apparatus to assist a patient paralyzed by spinal or other trauma, such as strokes or other illnesses, to perform a walking motion. An attendant supervises and works with the patient in exercise activities related to walking. Equipment used during supervised exercise includes a body harness worn by the patient and a treadmill. The body harness attaches to an overhead support that bears an adjustable portion of the weight of the patient while allowing contact between the patient&#39;s feet and the movable belt of the treadmill. A supervising attendant takes a position on the treadmill either in front of or behind the patient. 
     Before exercise begins, connection is made between the healthy legs of the attendant and the injured legs of the patient using rehabilitation apparatus according to the present invention. The rehabilitation apparatus includes a leg appliance and ankle appliance worn by the attendant and patient, with separate linkage between the leg appliances and the ankle appliances. A single piece of apparatus comprises two leg appliances adapted for interconnection between the attendant and patient, as well as two ankle appliances also adapted for interconnection between the patient and attendant. One or two pieces of rehabilitation apparatus may be used depending on the need for treatment to one or both of the patient&#39;s legs. For example, an injured left leg would require connection of the left leg of the patient to the left leg of the attendant. A paraplegic patient would require both legs to be connected to the legs of the attendant. 
     After positioning and connecting the rehabilitation apparatus between the patient and attendant, the treadmill may be energized causing the belt to move. As the belt slowly moves, the attendant begins to walk. The rehabilitation apparatus transmits the walking motions of the attendant through the connected leg appliances and linked ankle appliances to the patient&#39;s legs, depending on which are connected. Each step taken by the attendant at a position walking behind or in front of the patient causes stepping motion to be induced in and performed by the patient under the motivation and control of the rehabilitation apparatus. While an attendant&#39;s healthy legs lift and reposition a patient&#39;s injured legs, the attendant positioned behind the patient may also reach forward to the patient above the waist to assist with stability and weight transfer as the patient attempts to re-develop their ability to walk. The positioning of the attendant and use of the rehabilitation apparatus provide a much improved approach to increasing the confidence and desire of a patient to regain their ability to walk unaided. 
     More particularly, the present invention provides an apparatus adapted for coupling between an able-bodied attendant positioned behind a patient for rehabilitation of a leg damaged by paralysis. The apparatus comprises a leg appliance secured to a patient&#39;s shin, with a leg bracket adjacent to the patient&#39;s knee. A leg appliance or brace secured to an attendant&#39;s shin also includes a bracket adjacent to the knee. At least one connecting rod provides coupling from the leg bracket to the bracket of the leg brace to transmit motion from an attendant&#39;s leg to a patient&#39;s leg using forces acting from the leg brace to the leg appliance through the connecting rod. 
     An ankle appliance having an upper extension and a lower extension proximate the ankle is attached to a patient&#39;s foot and an ankle brace is similarly attached to an attendant&#39;s foot. The ankle brace has a brace upper extension and a brace lower extension adjacent the ankle of the attendant with the brace upper extension coupled by an upper ankle link to the upper extension of the patient&#39;s ankle appliance, while the brace lower extension is coupled by a lower ankle link to the lower extension of the ankle appliance. An offset link is connected to the attendant&#39;s or patient&#39;s ankle brace. This link extends rearwardly, where it slidably engages with a stationary support. This arrangement assists the attendant in transferring side-to-side foot motions to the patient without undue twisting or stressing to the ankle and leg of the attendant. Each of the upper link and the lower link are adapted to create movement of a patient&#39;s foot corresponding to movement of a foot of an attendant during walking whereby coordinated leg and ankle movement allows a patient&#39;s paralysis damaged leg to duplicate the walking motion of an able-bodied attendant&#39;s leg. It should be appreciated that the apparatus not only provides for the proper leg extension and foot placement for the walking action, but also utilizes appropriate parallel connections and link for communicating the tilting and side-to-side motions, respectively, of the foot as it moves through a step. 
     The beneficial effects described above apply generally to the exemplary devices and mechanisms disclosed herein of the rehabilitation apparatus for spinally injured patients. The specific structures through which these benefits are delivered will be described in detail herein below. 
    
    
     BRIEF DESCRIPTION OF DRAWINGS 
     The invention will now be described in greater detail in the following way of example only and with reference to the attached drawings, in which: 
     FIG. 1 is a side elevation showing an apparatus according to the present invention adapted to coordinate the walking motion of a suspended patient with that of an attendant. 
     FIG. 2 is a perspective view of a leg appliance for attachment to the shin of either a patient or an attendant. 
     FIG. 3 a  shows a perspective view of a right ankle appliance and offset link used in unifying movement between the feet of a patient and an attendant. 
     FIG. 3 b  shows a perspective view of a left ankle appliance and offset link used in unifying movement between the feet of a patient and an attendant. 
     FIG. 4 provides a side elevation showing interconnection between leg appliances and ankle appliances according to the present invention with the feet of a patient and an attendant placed flat against the surface of a treadmill belt. 
     FIG. 5 shows a side elevation of an interconnection between leg appliances and ankle appliances according to the present invention with the feet of a patient and an attendant raised over the surface of a treadmill belt. 
    
    
     DETAILED DESCRIPTION 
     As required, detailed embodiments of the present invention are disclosed herein. However, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, and some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but instead merely as a basis for the claims and as a representative basis for teaching one skilled in the art ways to variously employ the present invention. 
     Referring to the figures wherein like numbers represent like parts throughout the several views, FIG. 1 provides a side elevation of lifting equipment  10  used with an apparatus  12  constructed according to the teachings of the present invention for assisting a patient  14  to develop the ability to walk after sustaining a spinal or other debilitating injury or illness causing paralysis in one or both legs. While illustrating the preferred embodiment of the patient  14  in front of the attendant  16 , it should be understood that the invention is not limited to placing the patient  14  in front, and may also be used with the attendant  16  in front. 
     In preparation for the exercise of walking, the attendant  16  assists in placing a supporting harness  18  around the patient&#39;s hips and upper torso. The supporting harness  18  includes a suspension strap  20  for attachment to a support bar (not shown). The support bar is part of a support structure placed in close proximity to an exercise assembly  22 . The motion of the exercise assembly  22  aids the patient  14  in performing a walking motion. 
     After placing the patient  14  between the handrails  24  of the treadmill  22  and connecting the suspension strap  20  to the support bar, adjustment of the support structure positions the supporting harness  18  until the patient  14  adopts a suspended position that allows contact between the surface of the movable belt  26  of the treadmill  22  and the soles of the patient&#39;s shoes  28 . The suspended position allows leg movement for the patient  14  without the hindrance of up to full body weight. 
     With the patient  14  positioned and supported between the handrails  24  of the exercise assembly  22 , the attendant  16  attaches a leg appliance  30  to either or both shins of the patient&#39;s legs injured or paralyzed by spinal injury. An upper strap  32  attaches the leg appliance  30  to the shin just below the patient&#39;s knee. A lower strap  34 , positioned approximately at mid-calf, completes securement of the leg appliance  30  to a patient&#39;s shin. 
     The rehabilitation apparatus  12  according to the present invention also includes an ankle appliance  36  attached to the patient&#39;s shoe  28 , or directly about the foot by an ankle strap  38  and instep strap  40 . The ankle appliance  36  includes a bracket  42  having an upper extension  44 , a lower extension  46  and a foot stem  48  coupled therewith. 
     Having positioned the patient  14  and attached the leg appliance  30  and the ankle appliance  36 , the attendant  16  secures a leg brace  50  and an ankle brace  52  to match the number of appliances  30 ,  36  used by the patient  14 . Standing on the treadmill, the attendant  16  then makes connection from the attendant&#39;s leg brace  50  to the patient&#39;s leg appliance  30  by means of a connecting rod  54 . Similar connections are made between the attendant  16  and the patient  14  at the ankles, using an upper ankle link  56  and a lower ankle link  58 . The connecting rod  54  and upper and lower ankle links  56 ,  58  may be adjustable in length, and terminate in joints  60  adapted for rotation between the connector  54  and links  56 ,  58 , the leg appliance  30  and leg brace  50 , and the ankle appliance  36  and ankle brace  52 . The joints  60  may take any form that allows rotation between parts. Suitable structures include ball and socket joints, as well as other known types of rotatable bearings or linkages that may include such members as axle pins. Additional synchronization between the legs of the attendant  16  and patient  14  results when connectors  54  and links  56 ,  58  provide attachment between the outside and the inside of the patient&#39;s and attendant&#39;s legs. An offset link  62  may be attached to the attendant&#39;s ankle brace  52  and extend behind the attendant  16  over an offset link support  64  for assisting the attendant  16  in transferring side-to-side foot motions to the patient without imparting twisting or stress to the attendant&#39;s ankle and knee joints. As stated above, the attendant  16  can be either in front or behind the patient  14 . The offset link  62  can be attached to either the front or rear ankle brace  42 ,  52 . This offset link  62  further extends either in front of or behind the connected patient  14  and attendant  16 . In the preferred embodiment, the attendant  16  is behind the patient  14 , with the offset link  62  attached to the rear brace  52  trailing behind over the offset link support  64 . 
     Upon completion of assembly of the various parts of the rehabilitation apparatus  12 , the treadmill  22  may be operated to cause linear movement of the belt  26 . The onset of movement requires the attendant  16  to walk at the speed set by the moveable belt  26 . Leg movement of the attendant  16  causes coordinated movement of the affected legs of the patient  14  using forces transmitted through the rehabilitation apparatus  12 . With each stride, the heel of the attendant&#39;s foot makes initial contact with the surface of the moving belt  26  before the sole of the foot fully engages its surface for rearward movement. When this movement places the leg in a suitably extended position behind the attendant  16 , the heel raises and the attendant&#39;s toes become the only point of contact with the belt  26 . From this position, the attendant  16  lifts the affected foot and leg prior to executing forward extension of the leg to begin a new stride. Changes of the attendant&#39;s leg and ankle positions cause movement of the leg brace  50  and ankle brace  52  producing corresponding changes in the positions of the leg appliance  30  and ankle appliance  36  of the patient  14 . Each stride of the attendant  16  facilitates therapeutic movement of the injured leg(s) of the patient  14  who, being supported by the suspension strap  20 , expends minimal energy to execute a similar walking motion. 
     Having briefly described how an attendant  16  may assist in patient rehabilitation using an apparatus  12  according to the present invention, the various parts of the apparatus  12  will be described in greater detail with reference to FIGS. 2,  3   a  and  3   b . FIG. 2 shows a patient leg appliance  30  of similar construction to the leg brace  50  used by an attendant  16 . The leg appliance  30  includes a shin stem  66  and a substantially U-shaped leg bracket  68 . The shin stem  66  attaches just below a wearer&#39;s knee, being held there by tightening an upper strap  32  just below the knee, and a lower strap  34  approximately in the region of a person&#39;s calf. The straps  32 ,  34  may be held in position relative to the shin stem  66  using eyelets  70  as shown in FIG.  2 . Retention devices other than eyelets may be used as will be recognized by those having ordinary skill in the art. Such alternative retention devices include methods of permanent or temporary fastening of the straps  32 ,  34  to the stem  66 , including mechanical fasteners such as hook and loop fasteners or other forms of interference fasteners, riveted strap attachment, and sewn attachment of binding elements. 
     The correct position of a leg appliance  30  after tightening the upper  32  and lower  34  straps places the opposing limbs of the substantially U-shaped bracket  68  on either side of a wearer&#39;s knee. The opposing limbs of the bracket  68  include terminal openings  72  as points for pivotal joining of connecting rods  54  on either side of the knee. Preferably, the end of a connecting rod  54  includes a complementary opening for alignment with an opening  72  of the bracket and attachment thereto using an axle pin or other suitable connecting device that allows pivotal movement between a connecting rod  54  and a bracket  68 . Reference to FIG.  1  and FIG. 2 shows how a patient&#39;s leg appliance  30  and an attendant&#39;s leg brace  50  may be positioned and connected to coordinate leg movement between the patient  14  and attendant  16 . 
     Coordination of ankle movement between a patient  14  and attendant  16  requires the formation of links between an ankle appliance  36  and an ankle brace  52 , each of which have similar features as shown in FIGS. 3 a  and  3   b.  In the preferred embodiment illustrated In FIGS. 3 a  and  3   b,  the connection is of the parallel-linkage type. Each ankle appliance  36  includes a foot stem  48  that is angled to fit over the top of a wearer&#39;s foot. The foot stem  48  is attached thereto by means of an ankle strap  38  and an instep strap  40 , as exemplified in FIG. 1. A bracket  42  extending in front of the ankle has an upper extension  44  and a lower extension  46  in sliding engagement with the bracket  42 . In a preferred structure, the upper  44  and lower  46  extensions include an upper slot  74  and a lower slot  76 , with the bracket  42  having an upper orifice  78  and a lower orifice  80 . A suitable fastener, such as a threaded bolt and wing nut, may be used to hold the extensions  44 ,  46  to the bracket  42  with bolts inserted through the orifices  78 ,  80  and slots  74 ,  76 . The slots  74 ,  76  allow rotational adjustment of the upper  44  and lower  46  extensions for comfortable positioning of the extensions  44 , 46  around a wearer s ankle. After adjustment, the upper  44  and lower  46  extensions may be secured in position by tightening, such as a wing nut, or activating a similar locking mechanism that maintains the extensions  44 ,  46  in the desired position during exercise 
     A parallel linkage may be used between either or both of the leg and ankle apparatus. However, such a linkage is particularly suited for the ankle connection. This is because it is important that the patient&#39;s foot experiences more exactly the actions and movements of the attendant&#39;s foot during the therapy session. This exemplary arrangement between the ankle and/or foot linkages are shown in FIGS. 1,  4  and  5 . From these illustrations, it may also be appreciated that the link from patient-leg to therapist-leg and the link from patient-ankle to therapist-ankle also forms a parallel linkage of sorts between the right legs of the therapist  16  and patient  14  and the left legs of the therapist  16  and patient  14 . 
     Though not always appreciated, a person&#39;s foot must follow certain tilting movements for natural execution of the walking process. It is important that the patient&#39;s foot mimics the natural action that is imparted from the attendant&#39;s foot. Therefore, a parallel connection or linkage is aptly suited since it will not only lift and move the patient&#39;s foot forward, but the natural tilts and heal strikes of the foot will also be conveyed and experienced, thereby producing a more natural experience for the patient  14 , and better train the patient  14  for unaided walking, should rehabilitation to that extent possible 
     Assembly of the linked ankle appliance  36  and the ankle brace  52  may include attachment of an offset link  62  to either the lower extension  46  or upper extension  44  of the ankle brace  52 . In a preferred embodiment, the offset link  62  comprises an arcuate clip  82  adapted for attachment to the lower extension  46  of the ankle brace  52 . For use on the right side, an elongate stem  84  is connected to the right side of the arcuate clip  82 , and for the left side, an elongate stem  84  is connected to the left side of the arcuate clip  82 . The elongate stem  84  extends opposite the back of an attendant&#39;s heel for positioning on a trailing link support  64 . The sliding engagement between the stem  84  and the support  64  assists the attendant  16  in transferring side-to-side foot motions to the patient  14  without imparting a twisting or stress to the attendant&#39;s ankles and/or knee joints. Each of the arcuate clips  82 , upper extension  44 , and lower extension  46  include suitable points of pivotal interconnection for attachment of opposite terminal portions of an upper ankle link  56  and a lower ankle link  58  on either side of the patient&#39;s ankle and the attendant&#39;s ankle to allow coordinated movement between the ankles of the attendant  16  and the patient  14 . Joining mechanisms, previously described for joining leg appliances  30  to leg braces  50 , such as ball and socket joints and other well-known types of rotatable bearings or linkages, may be used for linking ankle appliances  36  to ankle braces  52 . 
     FIG. 4 shows interconnection of a rehabilitation apparatus  12  according to the present invention assembled as previously described. The leg appliance  30 , strapped to the patient&#39;s leg by upper strap  32  and lower strap  34 , further includes a shin stem  66  and a leg bracket  68 . An attendant&#39;s leg brace  50  also includes straps for holding the shin stem and leg bracket just below an attendant&#39;s knee. A connecting rod  54 , adjustable in length, is pivotally attached at coupling points  60  and directly translates movement of the leg brace  50  into similar movement of the leg appliance  30  allowing a patient to perform the same leg movement as the attendant. 
     As described above, coupling of the leg appliance  30  to the leg brace  50  preferably includes two connecting rods  54  with attachment of one rod to each end of each U-shaped leg bracket. The rehabilitation apparatus  12  also provides connection between the feet of an attendant and a patient using an ankle brace  52  linked to an ankle appliance  36  by an upper ankle link  56  and a lower ankle link  58 . Either or both of the links  56  and  58  may be adjustable in length such that relative orientation of the attendant&#39;s and patient&#39;s feet may be set. 
     Referring to the ankle appliance  36 , which may have parts in common with the ankle brace  52 , a pair of straps  38 ,  40  holds a foot stem  48  on top of the wearer&#39;s foot for deploying a bracket  42  that includes an upper extension  44  and a lower extension  46 . A bracket  42  needed here for facilitating the raising and lowering of the toes and heels of the attendant  16  and patient  14  during performance of the walking motion. The patient may be standing either behind or, preferably, in front of the attendant  16 . In either position, during the raising of an attendant&#39;s toes the belt  26  of a treadmill  22 , the upper link  56  moves rearward relative to the lower link  58 . Since the patient  14  is suspended in a partial weight-bearing condition with little or no control over the paralyzed leg(s), the movement of the links  56 ,  58  causes the patient&#39;s toes to lift in response to the corresponding movement by the attendant  16 . When the heel of the attendant  16  is raised, pivotal movement of the links  56 ,  58  in reverse to that just described causes the heel of the patient  14  to be similarly raised. As earlier described, the rehabilitation apparatus further includes an offset link  62  for controlling side-to-side foot motions as previously described. 
     FIG. 4 shows the leg positions of an attendant  16  standing behind a patient when the belt  26  of the treadmill  22  is stationary. The legs of both exercise participants are side-by-side so only one is visible in this side elevation. FIG. 5 illustrates the use of a rehabilitation apparatus according to the present invention on a moving treadmill  22  in a situation involving a patient  14  having only one leg paralyzed. The healthy, non-coupled legs of the patient  14  and attendant  16  are shown by a discontinuous-line in the background. The leg requiring assistance is shown In the foreground with a rehabilitation apparatus attached between the attendant  16  and patient  14 . Once the trailing leg has reached a suitable rearward position, the heel of the attendant begins to raise from the surface of the belt  26  of the treadmill  22 . This moves the upper and lower links  56 ,  58 , displacing the patient&#39;s heel from the belt  26  prior to the attendant&#39;s being raised and lifting the foot above the treadmill  22  before swinging the leg forward to begin the next stride. Transmission of each movement through the rehabilitation apparatus  12  causes the patient to perform a corresponding movement with his or her paralyzed leg. 
     In most cases, it is anticipated that leg paralysis will be only partial thereby allowing the patient  14  to exert at least some effort towards sustained walking exercise. Regardless of a patient&#39;s initial condition, one purpose of the new rehabilitation apparatus constructed according to the present invention is to refamiliarize the patient with the sensations of walking motion and to also provide therapy to strengthen the affected leg muscles, all working towards the ultimate goal of enabling the patient to walk unattended, if possible. 
     A rehabilitation apparatus and its components have been described herein. These and other variations, which will be appreciated by those skilled in the art, are within the intended scope of this invention as claimed below. As previously stated, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various forms.