Impedance Control of Two d.o.f. CPM Device for Elbow Joint

Abstract

Continuous passive motion (CPM) involves orthopedic or post-surgery physiotherapy. Following surgery to correct ulna collateral ligament (UCL) injury in the elbow, for example, excessively extending the UCL aggravates the injury and reaction force of the arm increases excessively near the end of the range of motion (ROM). Controlling pro/supination, i.e., rotary motion of the wrist, effectively suppresses reaction force, but may extend the UCL excessively. We propose a 2 d.o.f. (degrees of freedom) impedance controller as a CPM device for the elbow to suppress reaction force based on the musculoskeletal system.