[Muscular burden in current work activities exemplified by cash register work sites].

21 cash register operators (aged 18 to 49 years) have been studied in an industrial study. The investigation included the measurement of heart rate, bioelectrical muscle activity of the right and left M. biceps brachii and M. deltoideus and muscular endurance at 50% MVC. There were significant relationships between the movement of the left arm and the heart rate and the load of articles and the heart rate. The results in bioelectrical activity showed that there were a muscular load in the right and left muscles and findings of muscular fatigue in frequency distribution and in muscular endurance.