Motion Control will develop an innovative body-powered (BP) upper extremity (UE) prosthetic system which offers substantial improvements in functionality, comfort, and aesthetics, for persons with UE deficiencies at all levels. This Utility Arm system will in¬crease independence and work capabilities for users of arm prostheses, with less com-plexity than a full myoelectric arm system, and at lower cost. The Utility Arm hybrid version (BP elbow with electric Terminal Device (TD)) will allow easy transition from electric TD to BP TD, for work or recreation. Phase II will focus on completion of tooling to build prototypes of the Utility Arm for field trials, including: ¦A metal/plastic composite elbow in versions with mechanical elbow lock, as well as electric elbow lock. ¦A BP Gripper TD in a metal/plastic/urethane composite, improving function and aesthetics of BP TDs in an innovative, yet easy to manufacture, design. ¦A rugged quick disconnect that allows easy interchangeability of both BP and electric TDs. Field trials will be conducted with a group of eleven active prosthesis wearers, which will both validate the Utility Arm design, and guide any redesigns required to evolve the prototypes to the finished products.