Trapezius muscle activity and body movement at the beginning and the end of a workday and during the lunch period in female office employees

Abstract

The aim of this study was to analyze the activity of the trapezius muscle and the arm acceleration during the course of a workday in office employees. It was examined if there are significant changes in trapezius muscle activity in the afternoon compared to the morning work period and relationships to the level of arm acceleration during lunchtime. Nineteen female office employees were recruited. A one hour period of the work in the morning, afternoon, and lunchtime were compared. The measures of the trapezius muscle activity and muscle rest time (TR) did not significantly differ between working in the morning (TR: median 10%; range 1%–49) or working in the afternoon (TR: median 18%; range 2%–34%). The 90th percentile of arm acceleration during lunch time significantly correlated with less trapezius muscle activity in the afternoon compared to the morning values (RT: Spearman R=0.80; p<0.01). Differences in the duration and level of trapezius muscle activity were bigger between the subjects than between different work periods or between lunchtime and work. Furthermore it seems that higher arm accelerations during lunch may be beneficial in reducing trapezius activity in the afternoon compared to the morning values.

Shear-wave elastography for assessment of trapezius muscle stiffness: Reliability and association with low-level muscle activity

“…The trapezius muscle, particularly its upper portion, has been subjected to extensive research in view of its potential role in developing chronic upper back and neck syndromes [27][28][29][30][31][32][33][34]. During a 30-min writing task, the activity of the upper trapezius was reported to be fourfold higher in patients with chronic neck pain, compared to healthy controls [31].…”

“…One study found no differences in trapezius shear modulus between patients with chronic neck pain and controls [28]. Determining the limits of trapezius activity that represent an increased risk for developing neck syndromes is difficult since most studies used normalizations to non-standard reference tasks [27,29,30] instead of maximal voluntary contraction (MVC) tasks. Cui et al [32] reported the activity of upper trapezius to be 5-7% MVC during typing, with little difference between sitting and standing posture.…”