Fischer, S., & Kibele, A. (2010). A kinematic study on the dive-in behavior during swim start performance from the block. A paper presented at the XIth International Symposium for Biomechanics and Medicine in Swimming, Oslo, June 16–19, 2010.

This study examined the kinematic differences in the starts of elite male swimmers (N = 16). Start performance was studied in the course of a 50 m speed swim and measured by the elapsed time between the start signal and the passage of the head at 7.5 m. Block performance and head passage at 7.5 m were analyzed by two above water cameras. An underwater video system was used to examine the dive-in behavior.

Start performance was significantly correlated with the hip angle at water entry of the centre of mass (r = -0.72), the mean horizontal velocity during the dive-in phase (r = -0.72), and the maximal dive-in depth (r = -0.69). Significant differences in these parameters were found between good and poor starters. No differences were found in the mean horizontal velocity between starting signal and water entry, angle of the centre of mass trajectory at first water contact.

Implication. Three features to coach about a start dive are:

• Enter the water steeper rather than flatter (this should reduce the amount of splash (irrelevant water movement)).
• Practice diving out as far as possible (maximal horizontal velocity produced primarily by leg drive off the block) before entering the water.
• Dive deep so that resistance is reduced and more effective double-leg kicks are executed before surfacing.

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