Fig. 17. The above-elbow figure-eight harness. The basic structure consists of a loop about the opposite axilla, the front portion supporting the arm and the rear portion attaching to the control cable so that arm flexion gives forearm flexion and terminal-device operation. The piece of elastic inserted in the front portion provides for relative motion for elbow locking by arm extension, the elbow-lock control being attached to the nonelastic portion. Suspension is improved by the lateral support strap and indicated auxiliary straps when necessary. As in the below-elbow dual control ([link6]), the cable housing is split so that arm flexion gives forearm lift when the elbow is unlocked, the leather lift loop on the forearm shell serving as the distal reaction point. If it is difficult to start the forearm into initial flexion, two baseplates may be used on the arm socket. The length of the leather lift loop on the forearm shell should be such that, when the forearm is extended, the distance from the center of the cable to the center of the elbow is equal to the distance from the center ot the forearm to the center of the cable housing. This arrangement reduces the amount of force needed to start the forearm into initial flexion without increasing the excursion required for full forearm flexion.