This thesis is part of the scientific activities of the Christian Doppler Laboratory for Extremity Reconstruction and Rehabilitation at the Medical University of Vienna. It deals with the development of the functional model of an elbow joint which is electronically controlled. There are industrial solutions for electronically controlled arm prostheses. However, they are unsatisfactory in many ways – among other things with regard to their weight and its distribution as well as to their noise production. By developing a drive which is located externally, it is possible to reconstruct the weight distribution of a human arm. In this thesis, a concept of a drive which is located externally is selected and the necessary power supply is calculated. Furthermore, the construction as well as the production of an elbow joint and of a linear gear are described. With this elbow joint, it is possible to lift a weight of 3,3 kg in 2 s. The elbow joint and the linear gear are combined with the components of the work of Mr. Helmut Meissner. Together, they form a functional model of an electronically controlled arm prosthesis. The drive unit can be either located externally or directly placed on the forearm. With the drive unit being located externally, the weight distribution of the arm prosthesis corresponds to that of a human arm.