Accelerometer profile of motion of the pelvic girdle in breaststroke swimming

The aim of the study was to develop a method for measurement and analysis of kinematics of the pelvic girdle movement in breaststroke swimming to support training of technical skills. The measurements were performed in five elite breaststroke swimmers. A recording device for triaxial accelerations and triaxial rotational angular velocity was mounted on the dorsal part of the pelvic girdle of the athlete. The task of the athlete was to swim one length of the 50 m swimming pool with the intensity similar to competition. From the consecutive cycles of swimming motion, we developed individual mean graphical and numerical profiles of the kinematics of the pelvic girdle movement within the average cycle. Mean basic values of the characteristics were compared with the values documented in the literature obtained by means of the video analysis or using the method of measurement of the velocity of the unwound rope. The comparison revealed that the results in the group studied were very similar to the results obtained using other methods and were typical of elite athletes. Analysis of the motion profiles for the pelvic girdle in breaststroke swimmers indicated that the results obtained reflected individual technique of performing individual phases of swimming cycles. The proposed measurement method, presentation and analysis of the profile of the pelvic girdle motion in breaststroke swimming represents a good tool for fast and effective biomechanical evaluation of motion technique components.