Trapezius muscle pressure pain threshold and strain in the neck and shoulder regions during repetitive light work.

Perceived musculoskeletal discomfort caused by the repetition of a light work task was examined by rating the perceived musculoskeletal discomfort and measuring the muscle pressure pain threshold. Thirteen healthy female workers performed a repetitive light work task for 120 minutes. Based on the perceived musculoskeletal discomfort during the work task the subjects were assigned to one of two groups, i.e., those who reported most complaints and those who reported fewest complaints. The pressure pain thresholds of the trapezius muscles in the most-complaining group were significantly lower than those in the least-complaining group. The pressure pain threshold was logarithmically correlated both with the perceived musculoskeletal discomfort and with the EMG signal amplitudes.