A myoelectric electrode assembly for a prosthesis comprising a retention ring adapted to be inserted into a correspondingly shaped aperture in the wall of the prosthesis. The assembly also has a myoelectric electrode unit held within the retention ring by means of a gasket which surrounds the electrode unit and is in sealing engagement therewith. A portion of the gasket is received in and sealingly engages with an annular recess around the inside of the retention ring.
