EMG study of the pectoralis major (sternal portion), teres major, latissimus dorsi and deltoid medial muscles in volleyball players.

UNLABELLED The pectoralis major (sternal portion), teres major, latissimus dorsi and deltoid medial muscles has been studied through in the electromyography in 8 male individuals, who practice volleyball, youth category, (age between 15 and 17 (average 16.25), right-handed, involved in volleyball for about one year. The objective was to analyze the potential of action of these muscles engaged in the volleyball movements: service, spike, pass, set and blocking with and without ball. The work was developed in the laboratory of Electromyography and Biomechanics of Posture (Physical Education Faculty - State University of Campinas - UNICAMP). To caption the muscles action potential, surface electrodes were set with conductive gel and fixed on the skin, in the center of the muscles. It was used an electromyography Lynx with 6 channels. The apparatus calibration was 3000 microV; 1199.760 Hz. The sequential experiments without ball were performed for 10 seconds, and the sequential experiments with ball in 12 seconds. RESULTS None of the muscles presented significative difference (p > 0,05) when compared to the sequential movements executed with and without ball. When compared to the sequential movements executed without ball, the only muscles that presented significative differences (p < 0,05) were: pectoralis major / deltoid and latissimus dorsi / deltoid, for another hand when in the comparative of the movements with ball, all muscles when compared to the latissimus dorsi, presented a significance difference (p < 0,05). It is interesting to observe, that the general average and the standard deviation of the deltoid muscle (medial portion), teres major, and latis-simus dorsi were higher in the sequential movements executed without ball.