Muscular Load Levels in Performing Musicians as Monitored by Quantitative Electromyography

Nine professional violinists were investigated during performance by means of quantitative electromyography (EMG) of the trapezius, deltoideus, biceps and triceps muscles bilaterally. Five of the subjects suffered from performance-related pain in the neck and shoulder region; four of the subjects did not show any pain problems. The subjects repeatedly played a 6-second long standardized piece of music in the laboratory. The level of the average rectified EMG (AREMG) from the different muscles, detected by surface electrode, was recorded during play. The mean level of the normalized AREMG (NAREMG) from the left and right trapezius, the right deltoid, and the right biceps was significantly higher for the group with pain compared with the other group. For the left trapezius the mean NAREMG level was 7.76% for the group with pain compared with 3.35% for the non-pain group. In the right trapezius the mean NAREMG level was 9.60% for the group with pain and 4.07% for the other group. For the right deltoid the group with pain had a mean NAREMG level of 3.70% and the nonaffected group 1.92%. Finally for the right biceps the findings were 2.86% for the non-pain group and 5.72% for the pain group. The mean NAREMG levels during rest were approximately equal for the two groups. Because the AREMG level is a measure of exerted muscle force it was concluded that the group of musicians that had developed neck and shoulder pain used, in some muscles, significantly more muscle force for the task than did the group without pain.