Discomfort and load on the upper trapezius muscle when operating a word processor

Abstract

Surface electromyogram recordings from the descending part of the trapezius muscle and discomfort ratings were assessed for six female VDT wordprocessor operators during their work. Each operator was studied during three work periods of 3 to 5 hours on different days. During one of the work periods, short pauses (15 s) were introduced every sixth minute. A static local muscular load of 32 and 30% of the maximal voluntary contraction was found on the right and the left side, respectively. The median and peak muscular loads during work were low. There was a significant negative correlation between pauses and static load on the right upper trapezius muscle. The rating of perceived discomfort was less after the work periods with short pauses than after the work periods without.