Soleus pump

Abstract

A “soleus pump” (foot pump) applies an oscillatory movement to the sole of the foot so as to exercise the calf muscle and thereby prevent development of deep venous thrombosis. In one embodiment, the apparatus is placed under the lower leg of the patient, holding the leg in an optimal position without the necessity of strapping the apparatus to the patient or to the bed or table. The foot motion is applied through a foot pedal incorporating a safety feature which keeps the apparatus from jamming the patient's foot. In another operating mode, the motor drive may be withdrawn, so that the patient may drive the plate by voluntarily flexing the leg muscles, as a form of exercise. In another embodiment, two monopedal embodiments may be joined together to create a bipedal version of the invention, permitting both legs to be exercised at the same time. In yet another embodiment, the apparatus may be adapted for use by a patient sitting upright, for example, in a chair or airline seat.

We claim:  
     
         1 . An apparatus for exercising a leg, comprising: 
 means for supporting the leg so that the sole of the foot rests against a movable member, and the weight of the lower leg is not resting on the calf muscle or the back of the knee joint;    said movable member being secured in relation to said supporting means;    means for applying an oscillatory force to said movable member.    
     
     
         2 . The apparatus of  claim 1 , further comprising; 
 compressible means for linking said oscillatory means to said movable member, said compressible means limiting said force applied by said oscillatory means to said movable member, and providing a mode whereby said foot may apply a force to move said movable member in opposition to said force applied by said compressible means.    
     
     
         3 . The apparatus of  claim 2 , wherein said linkage of said compressible means is unidirectional.  
     
     
         4 . The apparatus of  claim 3 , wherein said compressible means comprises a torsion spring.  
     
     
         5 . The apparatus of  claim 1 , wherein said movable member is pivotally attached to said supporting means.  
     
     
         6 . The apparatus of  claim 1 , wherein said means for applying said oscillatory force is deactivated.  
     
     
         7 . The apparatus of  claim 2 , wherein said apparatus further comprises: 
 second means for supporting a second leg so that the sole of the second foot rests against a second movable member, and the weight of said second leg is not resting on the second calf muscle or the back of the second knee joint;    said second movable member;    second means for applying an oscillatory force to said second movable member;    second compressible means for linking said second oscillatory means to said second movable member, said second compressible means limiting said force applied by said second oscillatory means to said second movable member, and providing a mode whereby said second foot may apply a force to move said second movable member in opposition to said force applied by said second compressible means;    means for connecting said first support means to said second support means.    
     
     
         8 . The apparatus of  claim 7 , wherein said means for connecting said first support means to said second support means is adjustable.  
     
     
         9 . The apparatus of  claim 1 , wherein said movable member is slidably attached.  
     
     
         10 . The apparatus of  claim 9 , wherein said means for supporting the leg comprise: 
 a thigh support; and    an ankle support connected to said thigh support.    
     
     
         11 . The apparatus of  claim 10 , wherein said ankle support is vertically adjustable.  
     
     
         12 . The apparatus of  claim 11 , wherein said connection between said ankle support and said thigh support is lengthwise adjustable.