Abstract:
A support structure supports powered lifting means for lifting a patient from a wheelchair and moving the patient over a powered treadmill where the patient is lowered onto the treadmill. A control panel with a mirror thereon is supported at one end of the support structure, and a touch screen data entry/display device is supported by the panel. Two similar housings are disposed at opposite sides of the treadmill. Each housing pivotally supports a support arm which can swing away from the treadmill to facilitate access to the treadmill. Each support arm pivotally supports a first depending arm, and a second depending arm is pivotally supported therefrom. A pair of servo motors are supported by each support arm and are drivingly connected to the first and second depending arms to independently move the depending arms about the pivot axes thereof. A first attachment cuff is connected to the first depending arm for attachment to a patient&#39;s leg just above the knee. A second attachment cuff is connected to the second depending arm for attachment to a patient&#39;s ankle. The support arms are vertically adjustable, and the attachment cuffs are horizontally adjustable. The first attachment cuff is vertically adjustable, and the second attachment cuff floats vertically relative to its depending arm. Control means is connected to the drive means for the treadmill and the servo motors which move the depending arms to cause the treadmill and the depending arms to operate in a coordinated manner to cause the legs of the patient to move in a desired gait. Sensor means is also provided for sensing the home position as well as possible over-travel of the knee joint of the device.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention relates to a powered gait orthosis, and more particularly to a device to aid in research and rehabilitation of non-ambulatory patients and provide therapeutic exercise for those with spinal cord injuries, neurological impairments and those recovering from orthopedic procedures. The invention also enables the measurement of outcomes and records patient session data for progress analysis.  
           [0002]    Prior art devices for similar purposes are often not of sanitary construction and may require special electrical power sources and excessive site preparation. Additionally, such devices may be difficult to ship and setup. The prior art often requires the presence of more than one trained operator, thereby increasing the cost of such therapy. Additionally, therapists often perform portions of the therapy manually which does not result in uniform reproducible therapy to the patient. Prior art devices do not always provide easy patient access, and the devices may not successfully simulate a natural walking motion in the patients legs.  
         SUMMARY OF THE INVENTION  
         [0003]    The present invention is of sanitary construction since it utilizes components formed of steel and aluminum. The components are shipped in disassembled arrangement, and are then bolted together on site, thereby facilitating shipping and setup of the device. The devices is self-contained and free standing, requiring only common electrical power sources and minimal site preparation. A single technician is required to operate the invention. When a patient is properly position and attached to the device, movement of the legs is performed robotically by the device, and no manipulation of a patient&#39;s leg by a technician or therapist is required. However, the technician operating the device can adjust the operation of the components thereof in accordance with the requirements of different patients. The device has been successful in simulating a natural walking motion in legs of patients.  
           [0004]    A powered lifting device is provided for lifting a patient from a wheelchair and transporting him to a position over a treadmill, whereupon he may be lowered onto the treadmill. Similar leg actuator assemblies are disposed at opposite sides of the treadmill, each assembly including a support arm which is pivoted for movement away from the treadmill to facilitate access to the treadmill. Each support arm pivotally supports a first depending arm from which a second depending arm is pivotally supported. A pair of servo motors are supported by each support arm and are drivingly connected to the first and second depending arms to independently move the depending arms about the pivot axes thereof. A first attachment means is adjustably carried by the first depending arm for attachment to a patient&#39;s leg just above the knee; and a second attachment means is adjustably carried by the second depending arm for attachment of a patient&#39;s leg at the ankle.  
           [0005]    Each of the support arms is vertically adjustable independently of the other. The attachment means on the first and second depending arms are vertically and horizontally adjustable relative to the depending arm on which they are mounted. A control means includes a computer electrically connected to the drive means for the treadmill and the servo motors which operate the first and second depending arms so that the treadmill as well as the depending arms at opposite sides of the treadmill will operate in a coordinated manner to cause the legs of the a patient to move in a desired gait. Connected to the computer is an operator friendly touch screen interface with the ability to input, monitor and record pertinent data.  
           [0006]    Sensor means is also provided for sensing the home position of each second depending arm and for sensing over-travel of such second depending arms and the knee joints of the device to thereby prevent damage to the knees of a patient. Locking devices are provided for locking the powered lifting means in position and for locking the support arms in position. The lifting means also includes load cells for measuring the weight of a patient suspended thereby.  
           [0007]    When using the invention, a patient is initially fitted with a special harness and is lifted from a wheelchair to a standing position where weight is measured. A database containing individual set-up and historical information will be displayed on the touch screen. The patient is then moved over the treadmill and lowered thereon. The gait assist mechanisms are then attached to one or both legs of the patient. The percent of supported body weight can be adjusted as required as muscle strength of the patient develops. All component speeds are synchronized and controlled by operator input with treadmill speeds ranging from 0 to 2 mph. During a session, information such as blood pressure, heart rate, blood oxygen content, treadmill speed, session duration, etc. can be displayed and recorded for further analysis. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a side view of the invention showing a patient in a wheelchair prior to being lifted therefrom;  
         [0009]    [0009]FIG. 1 a  is a side view showing a patient after having been lowered onto the treadmill of the invention;  
         [0010]    [0010]FIG. 2 is an enlarged top view of the structure shown in FIG. 1;  
         [0011]    [0011]FIG. 3 is an enlarged end view, partially broken away, of the structure shown in FIG. 1 looking at the right side thereof;  
         [0012]    [0012]FIG. 4 is an enlarged view of a portion of the structure shown in FIG. 3 with certain elements removed for the sake of clarity;  
         [0013]    [0013]FIG. 5 is an enlarged view of a portion of the structure shown in FIG. 1 illustrating the parallelogram linkage of the lifting means.  
         [0014]    [0014]FIG. 6 is an enlarged top view of the powered lifting means of the invention;  
         [0015]    [0015]FIG. 6 a  is an enlarged top perspective view of the locking means for the winch frame;  
         [0016]    [0016]FIG. 6 b  is a sectional view taken on line  6   b - 6   b  of FIG. 6 a;    
         [0017]    [0017]FIG. 7 is a top view of the treadmill of the invention;  
         [0018]    [0018]FIG. 8 is a side view of the treadmill;  
         [0019]    [0019]FIG. 9 is a sectional view taken along line  9 - 9  of FIG. 7;  
         [0020]    [0020]FIG. 10 is an end view of the treadmill;  
         [0021]    [0021]FIG. 11 is a top view of the device with the support structure removed;  
         [0022]    [0022]FIG. 12 is a side view of a housing at one side of the treadmill and the structure supported thereby with one side panel of the housing removed for the sake of clarity;  
         [0023]    [0023]FIG. 13 is sectional view taken along line  13 - 13  of FIG. 3;  
         [0024]    [0024]FIG. 14 is a side view of the support arm of FIG. 13 with covers for the servo motor pulleys removed for the sake of clarity;  
         [0025]    [0025]FIG. 15 is an enlarged end view, partly in section, of the support arm shown in FIG. 14;  
         [0026]    [0026]FIG. 16 is an enlarged section through the hip joint portion of the structure shown in FIG. 15;  
         [0027]    [0027]FIG. 17 is an enlarged section through the knee joint portion of the structure shown in FIG. 15;  
         [0028]    [0028]FIG. 18 is an enlarged sectional view taken along line  18 - 18  of FIG. 15;  
         [0029]    [0029]FIG. 18 a  is an enlarged view of a portion of the structure shown in FIG. 18;  
         [0030]    [0030]FIG. 18 b  is an enlarged view of another portion of the structure shown in FIG. 18;  
         [0031]    [0031]FIG. 19 is a schematic wiring diagram of the control system; and  
         [0032]    [0032]FIG. 20 is a flow chart of the functions performed by the control means. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0033]    Referring now to the drawings wherein like reference numerals designate corresponding parts throughout the several views, FIGS. 1, 1 a ,  2  and  3  illustrate a rigid framework support structure formed preferably of steel including four upright beams  22 ,  23 ,  24  and  25  having base portions  22 ′,  23 ′ which are visible in FIGS. 1 and 25′ which is visible in FIG. 3, a corresponding base portion being provided at the bottom of beam  24 . These base portions may be bolted to a supporting surface to secure the beams in fixed position. A first cross beam  26  is connected at opposite ends as by bolting to the upper ends of beams  23  and  25 ; and a cross beam  27  is similarly connected at opposite ends to the upper ends of beams  22  and  24 .  
         [0034]    Longitudinally extending beams  30  and  31  have the opposite ends thereof secured as by bolting to cross beams  26  and  27 . A first brace member  33  has the opposite ends thereof connected as by bolting to beam  23  and beam  30 . A second brace member  34  has the opposite ends thereof connected as by bolting to beam  25  and beam  31 . A cross beam  36  has the opposite ends thereof connected as by bolting to beams  22  and  24 . A third brace member  38  has the opposite ends thereof connected as by bolting to cross member  36  and beam  30 ; and a fourth brace member  39  has the opposite ends thereof similarly connected to cross beam  36  and beam  31 . A further cross beam  40  has the opposite ends thereof connected as by bolting to beams  22  and  24 .  
         [0035]    A control panel  42  is supported between cross beams  36  and  40 , and a mirror  44  is supported on the right hand face of the panel as seen in FIG. 1 so that a patient may see himself when in position on the treadmill hereinafter described. A pivoted linkage  44  adjustably supports a touch screen  46  from the control panel.  
         [0036]    A pair of longitudinally extending rails  50  and  51  are secured as by bolting to the upper surfaces of beams  30  and  31 . As seen in FIGS. 1, 3,  5  and  6 , the lifting means includes a winch frame  53  which is slidably supported on rail  50  by a pair of spaced linear bearings  54  and is also slidably supported on rail  51  by a further pair of similar bearings  54 ′. Mounted on winch frame  53  are a winch motor  55  the output of which is connected through a gear box  56  and a coupling  57  to a reel  58  having a cable  60  wound thereon. A cover  61  is shown in FIG. 1 over some of the winch components. A lever  62  is pivotally supported on winch frame  53 . A pendant  64  is connected to the outer end of the lever and the pendant hangs downwardly as seen in FIGS. 3 and 4 with the lower end thereof connected to a hand grip  65 . The handgrip includes an operating control means for energizing and de-energizing the winch motor. Additionally, the hand grip can be used for releasing the locking mechanism associated with the winch frame as hereinafter described.  
         [0037]    Referring to FIGS. 6 a  and  6   b , the locking means for lever  62  is illustrated. Lever  62  includes spaced arms  62 ′ and  62 ″ with a spacer block  66  disposed between the ends thereof and connected thereto as by bolting. Spacer block  66  has an adjustment set screw  66 ′ threaded into a threaded bore provided through the spacer block. Beam  31  has a plate  31 ′ secured thereto as by bolting, and a stop mount  67  is secured as by bolting to plate  31 ′. A travel stop  68  is secured as by machine screws to stop mount  67  and includes a first cam surface  68   a  joining a second cam surface  68   b  which joins with a recess  68   c . The travel stop is shown which is mounted at the right-hand portion of the invention device as seen in FIGS. 1 and 2. A further travel stop  68 ′ is provided for locking the winch frame in position over the treadmill, stop  68 ′ being a mirror image of travel stop  68 .  
         [0038]    A pair of spaced support blocks  69  and  70  are carried by winch frame  53  and support opposite ends of a shaft S fixed within holes in the blocks. A lock pivot member  71  is of generally L-shaped configuration including a downwardly extending portion  71 ′ and a laterally extending portion  71 ″. A cam roller  72  is mounted on a shaft  72 ′ which is fixed within a hole formed in portion  71 ′ whereby the cam roller is carried by lock pivot member  71 . A lock arm stop  73  is mounted on portion  71 ′ of the lock pivot member  71  by machine screws. An adjustment set screw  73 ′ is threaded into a threaded hole formed through lock arm stop  73 .  
         [0039]    An integral spring mount  74  extends upwardly from the top of lock pivot member  71  and has a hole  74 ′ formed therethrough which receives one end of a first tension spring  75 . A further spring mount  76  is secured to lever arm  62 ′ as by bolting and has a hole  76 ′ formed therethrough which receives one end of a second tension spring  77 . As seen in FIG. 6, the opposite ends of springs  75  and  77  are connected to a bracket  78  secured as by bolting to the winch frame  53 . The springs will exert a continuous force on the upper ends of spring mounts  74  and  76  urging the lock pivot member  71  and the lever arm  62  to rotate counterclockwise about the axis X of shaft S. Such rotation of member  71  is prevented by contact of roller  72  with the wall of recess  68   c . Such rotation of the lever arm is prevented by contact of spring mount  76  with a set screw  79  threaded into a threaded hole formed in support block  70 .  
         [0040]    As the winch frame moves along rails  50  and  51 ; between the travel stops, cam roller shaft  72 ′ is disposed substantially vertically because of engagement of set screw  66 ′ with member  71 . When roller  72  comes into contact with cam surfaces  68   a  and  68   b , lock pivot member  71  is rotated in a clockwise direction about axis X and then rides into recess  68   c  where it is held in place by the tension of spring  75  to thereby lock the winch frame in position. At this time, lever  62  is held in a horizontal position under the influence of spring  77 .  
         [0041]    When it is desired to unlock the winch frame in order to move it to a different position, an operator pulls down on lever  62  causing spacer block  66  to move in a clockwise direction relative to axis X. Set screw  66 ′ then causes member  71  to move in a clockwise direction about axis X which causes roller  72  to move out of recess  68   c  whereupon the winch frame can be moved along its supporting rails and the roller  72  moves out of engagement with cam surfaces  68   b  and  68   a.    
         [0042]    As seen in FIGS.  3 - 5 , the lifting means also includes a trolley frame  80  supported by two linear bearings  82  slidably mounted on rail  50 , it being understood that two additional similar bearings are slidably mounted on rail  51 . The lower end of cable  60  is connected by an eye bolt  84  connected to a plate  85 . Rigidly secured as by bolting to the upper surface of plate  85  are two spaced similar elongated members  86  and  87 . A parallelogram connection is provided between plate  85  and the winch frame  53  as well as the trolley  80  including a first pair of links  90  and  91  having the lower ends thereof pivotally connected to opposite ends of member  86  at points  90 ′ and  91 ′ respectively. The upper ends of links  90  and  91  are pivotally connected to the trolley frame  80 . A second pair of links  93  and  94  are disposed parallel with links  90  and  91  and are pivotally connected at their lower ends to opposite ends of member  87  at points  93 ′ and  94 ′ in the same manner that links  90  and  91  are connected to member  86 . The upper ends of links  93  and  94  are pivotally connected to the trolley frame  80 .  
         [0043]    A further pair of links  100  and  101  are pivotally connected at their lower ends to intermediate portions of links  91  and  94  respectively at points  100 ′ and  101 ′. The upper ends of links  100  and  101  are connected to lugs  102  and  103  respectively at points  100 ″ and  101 ″. A pair of cross members  106  are connected between facing surfaces of links  90  and  93  at spaced points along the links. A pair of cross members  108  are connected between facing surfaces of links  91  and  94  at spaced points along the links. A pair of cross members  110  are connected between facing surfaces of links  100  and  101  at spaced points along the links.  
         [0044]    As seen in FIG. 4, a housing  112  is secured as by bolting to the undersurface of plate  85  and supports a pair of similar arms  114  which extend laterally from the housing and are pivotally mounted at points  115  for pivotal movement relative to the housing. Load cells  117  are supported within the housing and are in contact with the inner ends of arms  114  for measuring the weight of a patient suspended from arms  114 . The outputs of the load cells provide electrical signals which may be suitably recorded.  
         [0045]    As seen in FIGS.  3 - 5  similar plates  120  are supported at the outer ends of arms  114  for pivotal movement about the pivotal axes  122  thereof. Four threaded rods  124  have the upper ends thereof pivotally secured to opposite ends of plates  120 , the lower end of each of said rods being threaded into the open upper end of a cylinder  126 . The lower end of each cylinder  126  is open and is internally threaded to receive a threaded rod  128  the lower end of which is connected to a D-ring connector  130 . Each cylinder  126  is threaded in opposite directions at the opposite open ends thereof so that when cylinder  126  is rotated, the threaded rods and cylinder act as a turnbuckle to pull rods  124  and  128  toward one another or away from one another depending on the direction of the cylinder.  
         [0046]    Each of the D-rings is adapted to be connected with a strap  132  forming part of a harness H secured to the torso of a patient as seen in FIGS. 1 and 1 a . When a patient arrives in a wheelchair, the harness H is attached to the D rings. The winch of the lifting means is activated by use of the control means on hand grip  66  and the winch raises the patient vertically upward. As the patient rises, the parallelogram linkage ensures that the patient is supported in a generally vertical or standing position. As the patient rises, trolley frame  80  moves away from the winch frame into the position shown in FIG. 1 a . When the patient has been raised to the desired height from the wheelchair, the patient is moved manually to move the winch frame and trolley frame longitudinally of the device and then lowered into the position shown in FIG. 1 a  where his feet are supported by the treadmill.  
         [0047]    Referring to FIGS.  7 - 10 , the treadmill  140  of the invention is shown. The treadmill includes a frame  141  rotatably supporting rollers  142  and  143  at opposite ends thereof. A belt  144  is trained around the rollers in a conventional manner, and the usual deck assembly  145  is provided. A pair of plates  146  are connected to opposite sides of the frame of the treadmill as by bolting for a purpose hereinafter described. The roller  143  is rotatably supported as opposite ends thereof by a pair of similar bearings  147  mounted as by bolting on plates  146 . A servo motor  150  is supported by a bracket  151  connected to a gear box  152  drivingly connected to  153  of roller  143  as seen in FIG. 9  
         [0048]    As seen in FIG. 11, a pair of housings  160  are disposed at opposite sides of the treadmill and are connected to the treadmill as by bolting to plates  146  which are connected to opposite sides of the treadmill frame. A cross member  163  has the opposite ends thereof connected as by bolting to the facing inner surfaces of housings  160  and  161 . The two housings and the components supported thereby are of similar construction, one being the mirror image of the other, and accordingly, a single housing is described hereinafter, it being understood the description of the details of construction of one housing and the components supported thereby is equally applicable to both of the housings with similar components of both housings being given the same reference numerals.  
         [0049]    As seen in FIG. 12, housing  160  appearing at the bottom of FIG. 11 is shown with a side panel thereof removed. A carriage  165  is vertically movable within housing  160  and extends through a slot  166  disposed in one side of the housing. Two guide rods  168  and  170  are disposed within the housing with their upper ends fixed to the top member of the housing and with the lower ends fixed to a cross member  172  extending between and connected to opposite sides of the housing. The guide rods extend through linear bearings  168 ′ and  170 ′ supported by the carriage so that the carriage is guided in its vertical movement within the housing. A 24 volt permanent magnet motor  174  is supported by a cross member  175  extending between and connected to opposite sides of the housing. The output of motor  174  is connected to a lead screw  176  that is threaded through a threaded bushing  176 ′ supported by the carriage whereby rotation of the lead screw will cause vertical movement of carriage  165  along guide rods  168  either in an upward or downward direction depending of the direction of rotation of the lead screw.  
         [0050]    A seen in FIGS. 12 and 13, carriage  165  is rigidly connected as by bolting to member  180 . An upper plate  181  and a spaced lower plate  182  are attached as by bolting to member  180 . The upper plate  180  has been removed from FIG. 13 for the sake of clarity. A block  183  is secured as by bolting to a support arm  195  and receives a pivot pin  184  which extends therethrough and is fixed thereto, the upper and lower ends of the pivot pin being supported in bushings (not shown) in plates  181  and  182  respectively whereby support arm  195  is mounted for swinging movement outwardly of the treadmill.  
         [0051]    A hole  185  is formed in the upper surface of block  183  and is adapted to cooperate with a locking device  186  which comprises a hand knob having a threaded stem the lower end of which is not threaded and is adapted to be received in hole  185  to lock the support arm in its operative position as shown in the lower portion of FIG. 11. The threaded portion of the stem of the locking device is received within a suitable threaded hole formed in the upper plate  180 . When it is desired to release the locking device, it is simply unthreaded to the point where the lower end of the stem of the locking device clears hole  185 , whereupon support arm  195  can be swung outwardly. When the support arm is subsequently swung inwardly; the holes in the upper plate and block  183  are aligned with one another whereupon the locking device can be threaded downwardly to cause the lower end of the stem to again enter hole  185  so that the support arm is locked in operative position.  
         [0052]    A plate  190  is secured as by bolting to plate  180  and supports an inwardly extending hand hold  192 . As seen in FIGS. 3 and 13, hand holds  192  extend inwardly toward one another in position to be readily grasped by a patient when the patient is supported over the treadmill.  
         [0053]    As seen in FIGS. 13, 14 and  15 , the post  160  and support arm  195  appearing at the top of FIG. 11 are illustrated. A servo motor  200  is connected to a gear box  201  which is connected as by bolting to support arm  195 . An output pulley  202  is connected to the output of gear box  201 . A belt  204  is trained over pulley  202  and a pulley  206  hereinafter described. A servo motor  210  is connected to gear box  211  which is connected as by bolting to support arm  195 . An output pulley  212  is connected to the output of gear box  211 . A belt  214  is trained over pulley  212  and a pulley  216  hereinafter described.  
         [0054]    Referring to FIG. 16, the hip joint of the device is shown in detail. Pulley  206  is of annular construction and has a member  220  secured thereto as by a tapered bushing arrangement including bolts (not shown), member  220  being keyed to a shaft  222  for rotation therewith. Arm  195  has a hole formed therein which receives a tubular member  224  having a flange  225  thereon which is bolted to the arm by bolts  226 . Needle bearings  227  are disposed within tubular member  224  and rotatably support shaft  222 . A pulley  229  is keyed to shaft  222  for rotation therewith. A belt  230  is trained over pulley  229  for a purpose hereinafter described.  
         [0055]    Bearing  232  is supported on the right-hand end of shaft  222  and serves to rotatably support the upper end of a member  234  forming part of a first depending arm assembly hereinafter described. An end cap  235  is disposed over bearing  232  and is secured to member  234  by bolts  236 . Pulley  216  is rotatably supported on bearing  238  which is supported on the outer surface of member  224 . The pulley is secured to a member  240  by bolts  241 , member  240  being rotatably supported on bearing  242  which is supported on the outer surface of member  224 . Member  240  also forms part of the first depending arm assembly. As seen in FIG. 15, members  234  and  240  extend downwardly from the hip joint and form a first depending arm assembly which has a knee joint disposed at the lower end thereof.  
         [0056]    Referring to FIG. 17, the knee joint of the device is shown in detail. A bearing  244  is supported at the lower end of member  234 . A shaft  246  has one end thereof rotatably mounted within bearing  244 . The lower end of member  240  has a hole formed therein within which a bearing retainer  248  is disposed, the bearing retainer being secured to member  240  by bolts  249 . A pair of bearings  250  are disposed within retainer  248  and rotatably support shaft  246  at spaced points therealong. A pulley  252  has belt  230  trained therearound and the pulley is secured to member  254  by a tapered bushing arrangement including bolts (not shown), member  254  being keyed to shaft  246  for rotation therewith.  
         [0057]    A fitting  256  has a bore receiving the left-hand end of shaft  246 , and the fitting is fixed to the shaft for rotation therewith by a key and is held in place by set screws  258 . Fitting  256  carries a pair of spaced downwardly extending rods  260 , one of which is visible in FIG. 17, for a purpose hereinafter described. A brace mount  264  is fixed to shaft  246  for rotation therewith by a key and is held in place by a set screw  265 . A brace member  266  is connected to the brace mount as by bolting and extends downwardly to a fitting  268  which is connected as by bolting to the lower ends of rods  260  and the brace member as seen in FIGS. 14 and 15. A support block  270  receives the rods  260  which pass through bores in the support block. A pair of plates  272  extend between the rods  260  and brace member  266  and are connected thereto as by bolting.  
         [0058]    As seen in FIGS. 14 and 15, a thigh cuff assembly  274  includes a support member  276  having a horizontal portion  277  and a vertical portion  278 . A slot  280  is formed in depending member  240 . As seen particularly in FIG. 14, the inwardly facing face of member  240  has a recess  282  formed therein which receives a reduced part of the vertical portion  278  therein so that the vertical portion is adapted to slide vertically within the recess but cannot turn relative to member  240 . A through hole  284  is formed in vertical portion  278  for receiving a reduced threaded stem portion  286  of an adjusting knob  288  which is seen in FIG. 15, but has been removed as seen in FIG. 14. The knob includes a portion  290  which abuts a collar  292  formed on vertical portion  278 . A nut  294  has a threaded hole formed therethrough which receives the threaded stem portion of the adjusting knob. Nut  294  has opposite flat sides which are slidably received within slot  280  so that the nut may move vertically within the slot but cannot turn relative thereto. Flanges  296  extend laterally from the opposite flat sides of the nut and engage the inner face of member  240  so that the nut cannot pass through slot  280 . It is apparent that by loosening and tightening knob  288 , the vertical position of member  276  can be manually adjusted.  
         [0059]    A bracket  300  includes two lugs  302  extending therefrom. The bracket is connected to the horizontal portion of support member  276  for horizontal adjustment relative thereto. If a vertical section were taken through horizontal portion  277  looking toward the inwardly facing face of member  240 , the horizontal portion has a generally H-shaped cross-section with the opposite legs of the H forming the sides of the horizontal portion  277  with the sides being connected by a horizontal web section. This web section has an elongated slot (not shown) formed therethrough extending in a direction perpendicular to the inwardly facing face of member  240 . A threaded bolt (not shown) extends through the slot and is threaded into a threaded hole (not shown) formed in the upper surface of a bracket  300  which fits between the lower legs of the H-shaped cross-section of horizontal portion  277 . The horizontal position of the bracket can be adjusted by loosening the bolt and moving the bracket horizontally, whereupon the bolt can be tightened to hold the bracket in adjusted position.  
         [0060]    An arcuate thigh cuff  320  includes a strap  322  provided with VELCRO fastening portions for fastening the thigh cuff to the thigh of a patient just above his knee. The thigh cuff includes a pair of integral lugs  324  which abut lugs  302  on bracket  300 , a pivot pin  328  extending through aligned holes in the lugs to pivotally support the thigh cuff on the bracket.  
         [0061]    An ankle cuff assembly  330  includes a support member  332  having a vertical portion  333  and a horizontal portion  334 . A pair of linear bearings  335  are slidably disposed on depending rods  260 , the two bearings being connected to one another by a plate which is in turn secured to vertical portion  333  of support member  332  as by bolting. A constant force counter balance spring  340  is supported between plates adjacent support block  270  and is shown in dotted lines in FIG. 15. This spring is conventional and includes a band  342  interconnected to the vertical portion of support member  332  for counterbalancing the weight of the ankle cuff assembly.  
         [0062]    A bracket  350  includes two lugs  352  extending therefrom. The bracket is connected to the horizontal portion of support member  332  for horizontal adjustment relative thereto. This horizontal adjustment is identical to and operates in the same manner as the horizontal adjustment connection between support member  276  and bracket  300  previously described.  
         [0063]    An arcuate ankle cuff  362  includes a strap  364  provided with VELCRO fastening portions for fastening the ankle cuff to the ankle of a patient. The ankle cuff includes a pair of integral lugs  366  which abut lugs  352  on bracket  350 , a pivot pin  328  extending through aligned holes in the lugs to pivotally support the ankle cuff on the support member  332 . The ankle cuff assembly  330  is also shown in phantom line in FIG. 15 to illustrate the manner in which the assembly may float vertically along rods  260  to adjust the ankle cuff in accordance with the height of the patient.  
         [0064]    Referring to FIGS.  18 , and  18   a  as well as FIG. 16, a metallic indexing pin  370  is fixed to pulley  229 . A metal sensor  372  is mounted on bracket  374  which is secured by bolts  375  to cross member  376  which has the opposite ends thereof secured as by bolting to the inner facing surfaces of members  240  and  234 . This sensor is connected with the control means to sense the knee joint home position.  
         [0065]    Referring to FIGS. 18, 18 b  as well as FIG. 17, a metal target  380  having an outer arcuate flange portion  382  is secured to pulley  252  as by bolting. A pair of metal sensors  384  and  386  are mounted on bracket  388  which is secured as by bolting to cross member  390  which has the opposite ends thereof secured as by bolting to the inner facing surfaces of members  240  and  234 . These sensors cooperate with flange  382  to sense whether or not the flange has moved beyond either sensor and are connected with the control means to sense over-travel of the knee joint in opposite directions.  
         [0066]    Referring to FIG. 19, the control means of the invention is schematically illustrated wherein the touch screen  46  is electrically connected to a computer or programmable logic controller (PLC)  400  having a suitable program incorporated therein. A conventional keyboard  402  is electrically connected to the computer by a lead  404 . A lead  406  connects the computer to a motion controller  408  which in actual practice is a servo motion card disposed inside the computer. The motion controller is connected by leads  410 ,  412 ,  414 ,  416  and  418  with servo drives  420 ,  421 ,  422 ,  423  and  424  respectively. The servo drives are connected to the servo motor  150  for the treadmill, servo motor  200  for the right knee drive and  210  for the right hip drive. Servo motors  200 ′ and  210 ′ correspond to the servo motors  200  and  210  respectively, but are supported by the leg actuator assembly on the opposite side of the treadmill to provide the left knee drive and the left hip drive. Leads  430 ,  431 ,  432 ,  433  and  434  provide feedback from the servo drives to the motion controller and thence to the computer program. The hip and knee joint servos are slaved to the treadmill servos so that the various drive means operate in a coordinated manner to cause the legs of a patient to move in a desired gait. The control panel  42  is connected to the servo motors controlled thereby by suitable electrical cables  440  as seen in FIGS. 1 and 1 a.    
         [0067]    Referring now to FIG. 20, a flow chart sets forth the various functions performed by the schematic control means illustrated and described above in connection with FIG.  19 . The flow chart is self-explanatory and is readily understood by one skilled in the art.  
         [0068]    The invention has been described with reference to a preferred embodiment. Obviously, various modifications, alternatives and other embodiments will occur to others upon reading and understanding this specification. It is my intention to include all such modifications, alternatives and other embodiments insofar as they come within the scope of the appended claims or equivalents thereof.