A THREE-DIMENSIONAL ANALYSIS OF INTRA-CYCLE KINEMATIC PARAMETERS OF THE CENTRE OF MASS OF FEMALE BUTTERFLY SWIMMERS

Abstract

The analysis of intra-cycle velocity fluctuations in butterfly swimmers has been the subject of several swimming studies. Despite the fact that swimming is not a planar activity, most studies have examined these fluctuations with the use of two-dimensional (2D) analysis techniques, for example Maglischo et al. (1989), thereby introducing important limitations in both the data collection and analysis. In addition, the assumption of bilateral symmetry is untenable due to asymmetric patterns in the technique and asymmetries in the anthropometric characteristics (Arellano et al., 2003). Furthermore, Barbosa et al. (2003) showed that the hip does not represent properly the intracyclic variation in the kinematics of the centre of mass. Therefore, the purpose of this study was to investigate the intra-cycle fluctuation of the displacement, velocity and acceleration of the centre of mass in competitive female butterfly swimmers using three-dimensional (3D) analysis methods.