[Muscle activity and heart rate during rhythmical work on the hand ergometer. I. Heart rate, bioelectric muscle activity and mechanogram relative to the strength of contraction].

The experiments were carried out on 11 subjects ranging in the age from 23 to 37 years. Heart rate, integrated electrical activity from 4 muscles of the forearm and the hand and mechanical activity were measured simultaneously during rhythmical work using a hand-ergometer. The strength of the dynamic contractions was 20, 40, 60, 80 and 100% of a maximal voluntary contraction. The mean values of the maximal voluntary contraction obtained on male subjects were 57.3 kp and on female subjects 33.2 kp. The results showed that during dynamic contractions mechanical activity was related to the integrated electrical activity and both integrated electrial activity of 3 muscles and heart rate were linearly related to the load. The correlation coefficients for the EMG/EMG relationships of different muscles and for the EMG/heart rate varied between 0.83 and 0.98.