Kinematical Comparison Between Different Swimming Drills: Perspectives for Teaching in Front Crawl Technique

Abstract

The present study aimed to compare different technique drills at front crawl swimming from a kinematical standpoint. Six female swimmers (20.68±050 years, 57.83±10.50 kg body mass, 1.60±0.10 m height, and 22.39±2.61 kg/m² of Body Mass Index) were randomly allocated to perform three 25 m repetitions at front crawl swimming in the following conditions: i) normal; ii) closed hands; and iii) catch-up. The swimming velocity was measured with a speedometer, allowing to elaborate the time-velocity profile curves as well as collecting the maximum velocity (v_max), average velocity (v_med) and intracycle velocity variation (VIV). A stopwatch was used to determine the stroke frequency (FG) and then estimate the stroke length (DC) and stroke index (IN). The Friedman test was used for comparing the three conditions, followed by the Wilcoxon test (condition vs condition). The velocity-time profile curves showed that the catch-up drill is the most similar to normal front crawl in amplitude, but not in frequency. Higher v_max and v_med values were found in normal front crawl swimming compared to the two drills analyzed. While the FG was higher when swimming with closed hands, the DC and IN were higher in the catch-up mode and in the normal front crawl. It can be concluded that the catch-up is the drill that best resembles with the normal front crawl swimming and that compromises less the swimming efficiency.