Hand force symmetry during breaststroke swimming

Abstract

Hand force symmetry during breaststroke swimming The aim of this study was to analyze the hand force symmetry during the breaststroke and its relationship with swimmers’ performance. Seventeen breaststroke and/or medley specialists participated (12 men and 5 women, 19.5 ± 5.2 years and average performance of 73.4 ± 7% of the 50 m breaststroke world record). Each swimmer performed three repetitions of 25 m breaststroke swimming at maximal speed. Pressure sensors from Aquanex acquisition system were placed in both swimmers’ hands and Mean Force (Fmean) and Maximal Force (Fmax) were measured. The symmetry index proposed by Sanders was calculated and the time of a 50-m breaststroke trial at maximum speed (T50m) was used as a performance indicator. The variables were compared between hands using tests for dependent samples, and the relationship between variables were investigated using Spearman correlation test. The Fmean applied was 47.9 ± 16.7 N and 47.9 ± 14.5 N for right and left hands, respectively. The Fmean corresponded to 120.7 ± 43.6 N e 112.8 ± 35.7 N for right and left hand, respectively. No signifi cant differences were observed for none of the variables between right and left hands. Analyzing the subjects individually, it was possible to observe asymmetries levels up to 30.6% for Fmean and 35.9% for Fmax, however the relationship between symmetry indexes and the 50 m breaststroke performance was not statistically signifi cant.