Adjustable Stiffness-Based Supination–Pronation Forearm Physical Rehabilitator

This paper reports a new medical device together with a control strategy that focuses on the following tasks: (1) a trajectory tracking problem associated with the supination–pronation motion of the wrist–forearm for purposes of rehabilitation and (2) the adjustment of the system’s stiffness associated with the applied torque guaranteeing the angular motion of the rehabilitator as well as the resistance that potential users must overcome. These two tasks are oriented to regain the range of motion (ROM) of the wrist–forearm and to improve the strength of the associated muscles. It is worth mentioning that this device has not been clinically validated. However, the performance of the closed-loop medical device is validated with preliminary experiments with a healthy subject based on movement patterns involving passive, assisted-resisted, and active phases of rehabilitation protocols.