Biomechanical analysis of the grab, track and handle swimming starts: an intervention study.

This study examined the grab, track and handle swimming racing starts by elitelevel swimmers. Videography was used to analyse these starts before and after a period of dive start practice. Participants underwent 2-4 sessions weekly until 14 +/- 2 practice sessions were completed. Practice sessions comprised 5 grab starts (preferred technique) and 10 handle starts; or 5 grab starts and 10 track starts. The performance criterion measure was time to 10 m. Reaction, movement, block and flight times, flight distance, and the centre of mass at the set position were measured. No significant differences between dive groups in time to 10 m were revealed pre- or post-training. The training period further exaggerated the differences in centre of mass positions in the set position between the three techniques. The handle start revealed a significant change forward in the centre of mass that allowed for decreased movement and block times. The training period improved 10 m, reaction, movement, block and flight times irrespective of the technique used. Hence, regular dive start practice significantly improved the start performances of elite swimmers. Coaches should consider including regular dive practice sessions of approximately 15 minutes to improve dive start performances.