The improvement of models of human movements plays an important role in sports science. It is necessary to develop simple models of basic movements to determine the individual input parameters by nonlinear parameter estimation.The aim of this thesis is the improvement of a model for the elbow extension. The following issues will be addressed:a)Adaptation of the knee extensor measuring system for elbow extensor movements.b)Anatomic examinations of the elbow joint to improve the non-invasively measured parameters for the movement model of elbow extension. c)Kinematic investigation of the shoulder shift during elbow extension movements.d)Improvement of the existing geometric sub-model of elbow extension: development of several mathematical models for extension. In the course of the anatomic examinations, 100 elbow-, and shoulder specimens as well as 35 whole-body specimens were reviewed in two anthropometric measurement series.Additionally, 180 elbow extension measurements were performed by 10 male subjects and analyzed with a video screening system. The elbow extension measurements consisted of six dynamic and three isometric measurements to get the individual shifts of the shoulder joint during elbow extension.To simulate the elbow extension movement we used Matlab and Java.The anthropometric input parameters were geometrically improved using statistical relations from the anatomic examinations. Based on the kinematic investigation of the shoulder movement during the dynamic and isometric elbow extensions, measurements of time-dependent shoulder shifts were obtained. Different mathematical models of the shoulder shift were developed and the effect on the elbow extension was investigated.