As the motion sensor-based technology improves, more advances seem to be coming. For example, check this blurb and video how stroke recovery might be assisted by Microsoft's Kinect, specifically upper-limb motor functioning:
Stroke patients can get direct feedback about their recovery from the Kinect, which is able to capture the skeletal movements in real-time and relay the information back to the user. Stroke Recovery with Kinect features “three game-like exercises,” each of which requires the user to test his or her dexterity. This software could serve as an affordable, accessible addition to the recovery process for future sufferers. Check out a video of the program in action at Microsoft Research.