BODY ROLL AND HANDPATH IN FREESTYLE SWIMMING - AN EXPERIMENTAL-STUDY

The purpose of this study was to determine the influence of (a) body r oll, and (b) the motion of the arm relative to the trunk, on the media l-lateral component of the path followed by the hand during the pull p hase in freestyle swimming. Ten male swimmers swam three trials of fre estyle at a long-distance workout pace. Three-dimensional (3D) underwa ter videography was used to record the body roll angle-time history an d the path followed by the hand during the pull phase. A mathematical model was used to characterize the motion of a swimmer's right upper l imb in accord with 3D data from the videotape images, and to determine what the path of the hand would have been as a result of body roll al one. The contribution of body roll to the actual handpath was found to be nearly equal to the contribution of medial-lateral motions of the hand relative to the trunk.