A harness for an upper extremity below-elbow prosthesis. The harness includes a humeral cuff having medial and lateral pivot arms configured to removably attach to the socket of a below-elbow prosthesis. The humeral cuff enables a user to suspend the prosthesis without the need of a shoulder strap/harness or body harness. A cable system is affixed to the pivot arms and includes a wheel coupling the pivot arms to the control arm of a hook of the below-elbow prosthesis, thereby enabling users to operate the hook by simple flexion and extension of their arm.