Prostheses include a terminal device, a back-lock mechanism, a wrist, a limb-socket, and a harness system. The terminal device can be a five-fingered mechanical hand that provides a releasable adaptive grasp, and has independently flexible fingers. The limb socket can be 3D printed using a molded model of a remnant limb. The harness strap can encircle an unaffected limb and is coupled to the terminal device with a cable so that a user can control the terminal device. The harness system can include a 3D printed harness ring that couples to the cable.
