Synergistic control of stimulated pronosupination with the stimulated grasp of persons with tetraplegia.

The control of stimulated forearm pronosupination in concert with stimulated hand grasp of persons with tetraplegia has been investigated. It has been shown that hand grasp stability increased as supination was achieved. In accordance with this, a strategy of object acquisition has been proposed incorporating pronosupination and hand grasp. It has been proposed that, after object acquisition in the pronated posture, that supination be used to increase grasp stability. Three types of pronosupination control which act in synchrony with grasp were implemented incorporating this principle. The three types used were position-controlled pronator stimulation, touch-controlled pronator stimulation, and constant pronation stimulation. These controllers played a supporting role to the separate user control of hand grasp and release. The three controllers were evaluated and compared using a standardized test procedure that incorporated stimulated pronosupination control with stimulated grasp. Such methods of pronosupination control are likely to provide enhanced options for improving upper extremity function using electrical stimulation.