Motion analysis of front crawl swimming: Application of CAST technique for the estimation of 3D joint kinematics

Kinematic analysis of swimming is of interest to enhance swimming performances. Although the video recordings of underwater swimmers are widely diffused, the available methodologies are rarely precise enough to adequately estimate the three dimensional (3D) joints kinematics. Thus, a procedure to investigate the right upper limb’s 3D kinematics during front crawl swimming is proposed. The method is based upon the Calibrated Anatomical Systems Technique (CAST), a technique widely used in clinics which allows estimation of anatomical landmarks of interest even when they are not directly visible. An automatic tracking technique was adopted. Results showed that the complete 3D kinematics of at least twice as many frames than without CAST can be reconstructed.