MUSCULAR ACTIVATIONS DURING REPETITIONS OF SCULLING MOVEMENTS UP TO EXHAUSTION IN SWIMMING

The purpose of this study was to examine the influence of the repetiti on of sculling movements of the upper limb on muscular electrical acti vities during an exhaustive test in front crawl. Sir upper limb muscle s activities of nine nine swimmers were recorded, with telemetric EMG data acquisition system using active surface electrodes, during a 4 x 100 m front crawl lest conducted to exhaustion. The pattern of the mov ement was analysed from views obtained by recordings of two underwater cameras. Four phases in the stroke were identified from the hand coor dinates in the frontal plane (down-sweep, insweep, outsweep and recove ry). Raw EMG were rectified, integrated (IEMG) and normalized for each subject and for each muscle with respect to the highest IEMG obtained during the strokes and the phases. Results indicated that the repetit ion of the stroke up to exhaustion was not associated with an increase in IEMG for the total stroke and its phases excepted for the most act ivated muscle. The different sculling movements appeared to be clearly identify by the EMG approach whatever the trial. The contribution of the different muscles remained the same through the different repetiti ons lip to exhaustion. The larger muscular recruitments were obtained during the insweep phase when important antagonist activities were obs erved. It would be interesting to observe the EMG in a ne.rt 100 m rep etition when the swimmer could not sustain the same velocity.