Biomechanical analysis of the backstroke to breaststroke turns in age-group swimmers

Abstract

Four different backstroke-to-breaststroke turns performed by age-group swimmers were evaluated in a quasi-experimental pre–post study before and after a four-week intervention program.Ten girls and ten boys (12.1 ± 1.2 years old), from the same team and with regular competitive participation, performed three trials of each turn and were monitored using 12 aerial and 11 underwater Qualisys cameras plus two underwater tri-axial force plates. The 15 mpa#nbsp;-meter turning time improved over the intervention period for all turns (p < 0.01), with reductions of 5.3, 5.1, 4.9 and 4.8% for the somersault, open, crossover and bucket techniques. The highest improvement in mean time spent between pre- and post-intervention was found for the rotation phase (p < 0.01; 12.3–17.9%) and the fastest rotation of post-intervention was for the open turn (1.24 ± 0.10 seconds). There were no observed differences in the wall contact phase across all turn groups. Four-week intervention program can assist learning and improving of backstroke to breaststroke turning techniques particularly in rotation phase. Findings suggest that the preferred turn technique is not always the better to be used and that age-group swimmers are able to optimize their turning performance through regular turning sessions.