ORIGINAL ARTICLE   

Gazzetta Medica Italiana - Archivio per le Scienze Mediche 2022 March;181(3):103-9

DOI: 10.23736/S0393-3660.20.04343-0

Copyright © 2020 EDIZIONI MINERVA MEDICA

language: English

Technical characterization of the front crawl in children during the 50-m maximum test

Marcos FRANKEN ¹ ✉, Karla DE JESUS ², Kelly DE JESUS ², Flávio ANTÔNIO DE SOUZA CASTRO ¹

¹ Aquatic Sports Reseach Group, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil; ² Human Performance Study Laboratory, Universidade Federal do Amazonas, Manaus, Brazil

BACKGROUND: The aim of this study was to investigate front crawl technique and performance in children using kinematic variables in a 50-m maximum (T50) test.
METHODS: Thirty-five children performed the T50, from which images were obtained of the two 25-m laps (L1 and L2) by 2 synchronized cameras and processed with Kinovea software (Kinovea Org., San Francisco, CA, USA).
RESULTS: Comparisons between L1 and L2 revealed that the index of coordination (IdC: -4.4±4.4; -4.7±3.7%); stroke length (SL: 1.37±0.20; 1.39±0.32 m) and duration of entry and catch (32.1±6.7; 33.2±7.5%), pull (15.7±3.2; 16.5±3.7%), push (25.9±6.1; 26.1±6.1%) and recovery stroke phases (26.3±6.1; 24.2±6.0%) remained constant. The stroke rate (SR: 53.9±6.1; 46.8±6.7 cycles·min^-1) and mean swimming speed (SS: 1.22±0.13; 1.06±0.17 m·s^-1) were reduced, and the propulsive time (Tprop: 18.2±3.5, 21.3±5.5 s) increased. Significant correlations were found between performance and SL and Tprop (r=-0.72, P=0.010; and r=0.53, P=0.022, respectively).
CONCLUSIONS: SR, SS and Tprop were modified during the T50 in the front crawl in children, indicating technique variation, even in a short-distance event.

KEY WORDS: Biomechanical phenomena; Swimming; Child