The fitting of upper-extremity amputees requires special efforts, and its significance has been increased by the development of myoelectrically controlled prosthetic arm. Although an artificial hand only represents a relatively modest substitute for the missing hand of human beings, the efforts of designers and the achievements of manufacturers should not go unnoticed. Because of the development of myoelectrically controlled prosthetic arm, the amputee's standard of function can be improved and a cosmetic and functional solution provided. For control of the electromechanical hand, muscular potentials are received from the residual limb surface, amplified in the electrodes, and transmitted as control signals to the distal area. An important factor in providing a successful fitting is a reliable man-machine connection. This article summarizes the historic development and state of the art of the myoelectrically controlled arm prosthesis. The components and technical evaluations of the Myobock system as well as the procedures for fitting and fabricating a below-elbow prosthesis have been improved recently. A critical analysis of adaptive hands suggests that the prospects for the future are good.