Impedance control of pro-/supination based on the skeleton model of upper limbs

Continuous passive motion (CPM) is an orthopedic treatment or physiotherapy method after surgery or injury by external continuous force. In CPM for the elbow joint, it is effective to reduce an excessive reaction force from a subject by controlling pro-/supination of forearm. The ulna collateral ligament in the elbow joint is extended due to pro-/supination of forearm, and it appears that extension of the ligament aggravate contracture disorders. Thus, it is required to suppress the excessive extension of the ligament. In this paper, an impedance control which suppress the excessive extension of the ligament due to the pro-/supination of CPM device is proposed, and the trajectory of extension of the ligament while CPM training with proposed controller is clarified by skeleton model.