Abstract The purpose of this study was to identify the relative trajectories of the wrist and the elbow in reference to the shoulder displacement. 44 swimmers were filmed during the 100m freestyle races of the national Championships, using two videocameras. According to Schleihauf's method, the coordinates of the wrist, the elbow and the shoulder were obtained The displacement of the wrist, elbow and shoulder were analysed with an external reference, in an antero-posterior axis. The wrist had a sinusoIdal path even if it had the same exit and entry points. During the middle of the time of the stroke cycle, this joint moved backward, and the population was very heterogeneous. For the elbow, the sinusoIdal path was flater. This joint moved never backward of the entry point. Its range was 0.96 m The shoulder and the hip moved regulary and parallely during all the stroke. In reference to the shoulder displacement, the wrist seemed to slip backward during the middle time of the aquatic stroke, contrary to the elbow. It appeared a projection of the shoulder forward the elbow. Keywords: Kinematic parameters, upper ann, trajectories, reference.