Prosthetic joint lock and cable mechanism

A joint lock and cable arrangement for an externally powered prosthesis, the arrangement allowing shoulder and/or elbow joint movement of a prosthesis through the use of a single driving motor. The joint lock system includes a release solenoid and an electronic circuit which couples the solenoid and the driving motor, the release solenoid being activated to cause locking at a timed period after the motor is energized, so as to permit the desired operation of the associated joint for such timed period. The arrangement enables the use of a single motor to drive the shoulder joint and elbow joint of a prosthesis, and provides operation of a terminal device when both joints are in locked condition.