Backstroke start performance prediction

The backstroke start offers different concern than the ventral techniques since swimmers begin the race almost at water level and have to organize their actions to achieve less water resistance during take-off and flight phases. This study aimed to predict the backstroke start time when swimmers using start variant with hands on highest horizontal handgrip and feet on wedge. Ten competitive swimmers (mean s: age 21.1 5.36 years, stature 1.78 0.04 m, body mass 72.82 10.05 kg) performed four 15-m maximal repetitions of the studied start variant with 2 min rest between trials. Swimmers were videotaped in the sagittal plane for two-dimensional kinematic analysis using a dual media set-up with two stationary cameras. Surface and underwater cameras were aligned and placed 0.15 m above and 0.20 m below water level, respectively. Forward stepwise multiple linear regression analysis was computed for 5-m backstroke start time prediction, being the kinematical variables with highest correlation with start time selected for the model. The relative take-off phase time and resultant centre of mass velocity at centre of mass immersion were the variables that entered as backstroke start time predictors (R2 adjusted = .474). Augment in take-off time and resultant velocity during flight might reduce 5 m start time. Our study attempted to estimate backstroke start performance using multiple linear regression analysis; however, future studies should implement computational intelligence algorithms to compare results achieved by both prediction tools.