INTRODUCTION: Characterization of the breaststroke technique, regarding the relationship between kinematic and neuromuscular parameters. METHOD: Surface electromyographic signals (EMG) were used to analyze the dynamics of neuromuscular activity of the muscles pectoralis major (PM), biceps brachii (BB), triceps brachii (TB) and anterior deltoid (AD), in twelve national elite swimmers. A couple of cameras (an underwater camera and an above the water surface camera) were used to provide a dual projection that permits analysis of kinematic variables (Speed, SF, SL) in the 200 m breaststroke event. RESULTS: Swimming speed decreased from 1.41 (0.07) to 1.16 (0.09) m.s-1(P<0.05). Stroke length decreased from 2.32 (0.37) to 1.96 (0.24) m, while stroke frequency suffered decrease from 37.52 (5.16) to 34.40 (3.58) cycle/min of 1st lap 50 m until the 3rd lap of 50 m, slightly increasing in the last lap to 35.82 (3.39) cycle/min. Blood lactate increased from 1.12 (0.22) to 12.00 (3.23) mmol.L-1. EMG results indicated increase in frequency concerning amplitude for all muscles studied: BB, PM and TB, except for the AD. Negative correlation between speed frequency, SF and SL was obtained, i.e. to the muscles BB, TB and PM there was a correlation between speed, SF and SL, meaning that as the kinematic variables increase, the frequency decreases. The correlations suggested that the neuromuscular activation presents a direct correlation with the kinematic variables, especially for frequency reduction in the BB, TB and PM muscles, and to a high extent and correlation with the kinematic variables in PM. CONCLUSION: The relationship between the kinematic variables and EMG is decisive in the swimming performance evaluation, in training exercises outside the pool to increase muscular endurance of muscles involved in the breaststroke technique.
swimming; kinematics; EMG; amplitude; frequency
