1. Backstroke to Breaststroke Turning Performance in Age-Group Swimmers: Hydrodynamic Characteristics and Pull-Out Strategy
- Author
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Ricardo J. Fernandes, João Paulo Vilas-Boas, Márcio Borgonovo-Santos, Phornpot Chainok, Leandro Machado, Karla de Jesus, and J. Arturo Abraldes
- Subjects
Orthodontics ,Drag coefficient ,Intervention program ,Foot ,Health, Toxicology and Mutagenesis ,lcsh:R ,Public Health, Environmental and Occupational Health ,lcsh:Medicine ,030229 sport sciences ,Kinematics ,Athletic Performance ,Article ,Biomechanical Phenomena ,Inverse dynamics ,03 medical and health sciences ,0302 clinical medicine ,Drag ,hydrodynamics ,Breaststroke ,age group ,swimming ,drag ,strategy ,030217 neurology & neurosurgery ,Mathematics - Abstract
We compared the hydrodynamic characteristics and pull-out strategies of four backstroke-to-breaststroke turning techniques in young swimmers. Eighteen 11 and 12-year-old swimmers participated in a 4 week intervention program including 16 contextual interference sessions. The hydrodynamic variables were assessed through inverse dynamics, and the pull-out strategy kinematics were assessed with tracking markers followed by 12 land cameras and 11 underwater cameras. Swimmers randomly completed sixteen 30 m maximal backstroke-to breaststroke-open, somersault, bucket and crossover turns (four in each technique) with a 3 min rest. The data showed higher drag force, cross-sectional area and drag coefficient values for the first (compared with the second) gliding position. The crossover turn revealed the highest push-off velocity (2.17 ± 0.05 m.s−1), and the somersault turn demonstrated the lowest foot plant index (0.68 ± 0.03, 68%), which could have affected the first gliding, transition and second gliding depths (0.73 ± 0.13, 0.86 ± 0.17 and 0.76 ± 0.17 m). The data revealed the consistency of the time spent (4.86 ± 0.98 s) and breakout distance (6.04 ± 0.94 m) among the four turning techniques, and no differences were observed between them regarding time and average velocity up to 7.5 m. The hydrodynamic characteristics and pull-out strategy of the backstroke-to-breaststroke turns performed by the age group swimmers were independent of the selected technique.
- Published
- 2021