Compensatory Motion During a Bilateral Lifting Task for Transradial Prosthetic Design

Current improvements in the design of a transradial prosthesis include advanced technology in control systems and electronics that improve its functions. However these improvements often require excess mass distally along the prosthesis. A transradial prosthesis without a dynamic wrist component may cause awkward compensatory motion in the shoulder and elbow. It may be important to consider bilateral tasks such as lifting a 2.27 kg (5 lb.) box during the design process of a transradial prosthesis. The main purpose of this study was to determine if restricting motion of the wrist and forearm and thus simulating a basic transradial prosthesis, would cause significant compensatory movement(s) at the shoulder and elbow of either the affected or non-affected limbs during a bilateral lifting task. The second purpose of the study was to determine if the location of added mass of 96 g (mass of an electrical wrist rotator) would affect shoulder and elbow angles of both sides during the lifting task.