"If I can't do it once, why do it a hundred times?": Connecting volition to movement success in a virtual environment motivates people to exercise the arm after stroke

We are attempting to develop therapeutic technology that individuals with substantial arm weakness and minimal hand function after stroke can use to improve their movement ability without the continuous presence of a rehabilitation therapist. We have developed a device called Therapy WREX (T-WREX) that is comprised of four main features: 1) a passive, gravity-balancing arm support (based on WREX -Wilmington Robotic Exoskeleton) that allows a wide range of arm motion 2) a grip sensor that detects even trace amounts of grasp 3) virtual reality exercises that simulate activities of daily living, and 4) software that provides feedback about task performance. Initial clinical testing indicates that chronic stroke patients can significantly improve their movement ability with T-WREX. We have also found that patients strongly prefer using T-WREX for therapy compared to conventional, self-directed, tabletop exercises. This paper reports the results of a follow-up survey conducted with 11 subjects to gain further understanding about the basis for this preference. The results suggest that subjects prefer T-WREX because it is more interesting, and because it allows them to be more successful with their movement attempts. Further, each of the four features of TWREX had significant value to the subjects, suggesting that their combination is synergistic.