The purpose of this study was to evaluate of the tumble turn in swimming based on an elliptical model. Fifteen junior male swimmers were asked to perform 15 m round trip crawl including a tumble turn as fast as possible. A side view of the turn was analysed by the 2D-DLT algorithm. The trajectory of the head during the rotation phase was approximated by an elliptic model (r >= 0.90). The correlation between the elliptic indices and 15 turn properties were calculated. These elliptic indices were as follows: the inclination showed 65.9 ± 7.0 deg, the major axis indicated 0.51 ± 0.08 m, and the minor axis was 0.34 ± 0.10 m. The inclination significantly correlated with the 15m turn-out time 7.72 ± 0.36 sec (r = 0.795, p < 0.01). The minor axis significantly correlated with the 3 m turn-in time 2.21 ± 0.12 sec (r = 0.569, p < 0.05). lt was suggested that a shallower inclination and flattened of the elliptic trajectory of the head during the rotation phase had advantageous to turn performance.
© Copyright 2014 XIIth International Symposium for Biomechanics and Medicine in Swimming. Published by Australian Institute of Sport. All rights reserved.