Muscle excercise devices and associated methods

Abstract

A muscle exercise device can include a crank having an axis of rotation. A first arm can be connected to the crank so that a downward external force applied to the distal end of the first arm causes rotation of the crank. The devices of the present invention can further include a second arm to which a counterweight is connected. Optionally, an assist mechanism other than a counterweight can be used to provide upward movement of the first arm with minimal application of force by a subject. A retrofit kit can be provided for modifying an existing device such as an ergometer or road bicycle. The retrofit kit can include a counterweight and a fastener for attaching to the device to the existing device. The devices of the present invention allow for increased exercise capacity, isolation of muscle groups, and biomechanical forces which closely approximate comparable paired limb motion.

1 . A muscle exercise device, comprising: 
 (a) a crank having an axis of rotation;    (b) a first arm connected to the crank and extending substantially perpendicular from the axis of rotation, configured so that a downward external force applied to the distal end of the first arm causes rotation of the crank;    (c) a second arm connected to the crank and extending substantially perpendicular from the axis of rotation in a direction opposite to that of the first arm; and    (d) a counterweight operatively connected to the second arm and weighing from 5 to 70 pounds.    
   
   
       2 . The device as in  claim 1 , further comprising a brake operatively connected to the crank and configured to resist rotation of the crank.  
   
   
       3 . The device as in  claim 1 , wherein the counterweight comprises lead.  
   
   
       4 . The device as in  claim 1 , wherein the counterweight comprises iron.  
   
   
       5 . The device as in  claim 1 , wherein the counterweight comprises a hollow container having an interior and at least one sealable opening providing access to the interior.  
   
   
       6 . The device as in  claim 1 , wherein the counterweight has a weight of about 20 to 40 pounds.  
   
   
       7 . The device as in  claim 1 , wherein the counterweight is connected to the second arm by a threaded fastener.  
   
   
       8 . The device as in  claim 1 , wherein the counterweight is connected to the second arm by an interference fit.  
   
   
       9 . The device as in  claim 1 , wherein the counterweight is connected to the second arm by a clamp.  
   
   
       10 . The device as in  claim 1 , wherein the muscle exercise device is an ergometer, bicycle trainer, or exercise bicycle.  
   
   
       11 . The device as in  claim 1 , further comprising a secondary assist mechanism operatively coupled to the crank.  
   
   
       12 . The device as in  claim 1 , further comprising a frame retaining the crank in a fixed position and including a seat coupled thereto in a position suitable for use in extension and flexion motion of legs of a subject.  
   
   
       13 . The device as in  claim 1 , further comprising a foot rest attached thereto, said foot rest having an upper surface and a lower surface, and being configured so that a first foot of an exercising subject can rest on the upper surface while a second foot of the subject is in operative contact with the first arm.  
   
   
       14 . The device as in  claim 1 , further comprising a stationary shield situated lateral to the counterweight and configured to prevent the counterweight from striking an exercising subject.  
   
   
       15 . A retrofit kit, comprising: 
 (a) a counterweight; and    (b) a fastener configured for attaching the counterweight to an ergometer or bicycle trainer crank arm.    
   
   
       16 . The retrofit kit of  claim 15 , further comprising a set of written installation instructions corresponding to a particular configuration of the ergometer crank arm.  
   
   
       17 . The retrofit kit of  claim 15 , further comprising a tool for removing an existing pedal and/or securing the fastener.  
   
   
       18 . A method of exercising musculature associated with a single limb, comprising the steps of: 
 (a) applying a downward force to an arm operatively connected to a crank, said force being sufficient to rotate the crank so that the arm moves from an upper position to a lower position; and    (b) return assist rotating the crank sufficient to continue rotating such that the arm returns to the upper position, wherein the return assist rotating is assisted by a counterweight weighing from 5 to 70 pounds.    
   
   
       19 . The method of  claim 18 , wherein an assisted power curve during the steps of applying and return assist rotating substantially corresponds to a non-assisted power curve each measured at a common rotational velocity.  
   
   
       20 . The method of  claim 19 , wherein a deviation at maximum extension and a deviation at maximum flexion between the assisted power curve and the non-assisted power curve are each less than about 75%.  
   
   
       21 . The method of  claim 20 , wherein the deviation at maximum extension is less than 10%.  
   
   
       22 . The method of  claim 18 , wherein a CO 2  consumption for single limb exercise is within 20% deviation of a CO 2  consumption for paired-limb exercise at a common power per subject.