Robotic Road to Recovery 
Robots to boost the effectiveness and productivity of rehab
MIT Technology Review - November/December 1999 - page 34
By Mark Dwortzan

Systems designed by Neville Hogan and Hermano I. Krebs of MIT simultaneously
deliver therapy and measure recovery of limb control. Playing specifically
designed video games, the patient maneuvers the robot's mechanical arm
horizontally, moving it like an oversized computer mouse to work the wrists,
elbows and forearms at graded levels of resistance. A computer records the
robot arm's position, velocity and the force the patient exerts.  

http://www.techreview.com/articles/nov99/benchmark4.htm
http://web.mit.edu/hogan/www/