Prosthetic devices and, more particularly, modular myoelectric prosthesis components and related methods, are described. In one embodiment, a hand for a prosthetic limb may comprise a rotor-motor; a transmission, comprising a differential roller screw; a linkage coupled to the transmission; and at least one finger coupled to the linkage. In one embodiment, a component part of a wrist of a prosthetic limb may comprise an exterior-rotor motor, a planetary gear transmission, a clutch, and a cycloid transmission. In one embodiment, an elbow for a prosthetic limb may comprise an exterior-rotor motor, and a transmission comprising a planetary gear transmission, a non-backdrivable clutch, and a screw.