Racing start safety: head depth and head speed during competitive swim starts into a water depth of 2.29m

Abstract

The head depths and head speeds of swimmers attained following the execution of racing starts during competition have not been well described. To address this, 211 competitive starts were filmed into a starting depth of 2.29 m with a block height of 0.76 m. Starts were stratified according to age, sex, stroke, and swim meet. Dependent measures were maximum depth of the center of the head, head speed at maximum head depth, and distance from the wall at maximum head depth. Significant main effects existed for age for all three measures: F(1, 106) = 13.33, p < .001, F(1, 106) = 18.60, p < .001 and F(1, 106) = 70.59, p < .001, respectively. There was a significant age by sex interaction, F(1, 106) = 5.36, p = 0.023, for head speed. In conclusion, older swimmers performed starts that were deeper and faster than younger swimmers and nearly all starts exceeded the threshold speeds for injury. As compared to starts previously reported into 1.22 m, starts were deeper, slower, and farther from the starting wall at maximum head depth