Measurment of butterfly average resultante impulse per phase

• Autor(a) principal: Barbosa, Tiago M.
• Data de Publicação: 2002
• Outros Autores: Silva, José, Sousa, Filipa, Vilas-Boas, João Paulo
• Idioma: eng
• Título da fonte: Repositórios Científicos de Acesso Aberto de Portugal (RCAAP)
• Texto Completo: http://hdl.handle.net/10198/17833
• topic: Swimming; Butterfly stroke; Kinematics; Impulse

The aim of this study was to measure the average resultant impulse (ARI) per phase of the stroke cycle in butterfly and to analyse the variability of ARI according to the adopted breathlng technlque .. The sam pie was camposed of 6 male Portuguese swimmers at national and Internatlonal leveI. 6 cameras were set. obtaining non coplanar images (2 "dual media" images included). The study comprised the kinematical analysis of stroke cycles of the butterf1y stroke using the "Ariel Performance Analysis System" from Ariel Dynamics Inc. and a VCR at a frequency of 50 Hz. The ARI was calculated using the mean horizontal acceleration of the center of mass in each phase, the absolute duration af each phase and the body mass of the swimmer. Comparing the ARI according to the breathing technique adopted in each phase of the stroke cycle, we only observed significant differences in the outsweep. Comparing the intra-cyclic variations of the ARI in the different breathing techniques adopted, the arm's recovery when compared with the remained phases presented a significantly lower ARI.