A COMPENSATING SHOULDER JOINT TO ASSIST THE SHORT TRANSHUMERAL AMPUTEE

The typical problem patient has a transhumeral amputation 30 to 60 mm below the axilla. No matter how well the socket is made, the moment arm in the socket is too little to sustain the four foot-pound torque of a typical advanced prosthesis when working out in front. Matters get worse if the prosthetic terminal device carries a load. A prosthesis that solves this problem must compensate for the gravitational torque generated by the prosthesis itself so that all user generated torque can be used to position the prosthesis and to support the terminal device load