An experimental study of shoulder muscle activity and posture in a paper version versus a VDU version of a monotonous work task

Abstract Body posture and trapezius EMG activity of twelve subjects were evaluated in an experimental VDU-based work task and a paper-based task with the same work content. Work pace was faster with maintained quality (number of errors not significantly changed) in the VDU version of the work task. The seated posture was more upright. A low-level static EMG activity component was present most of the work time in both versions of the task. The EMG activity level was similar or decreased in the VDU version. Both the posture and the EMG activity showed significantly less variation in the VDU version. It is hypothesized that the decreased variation of physiological load patterns (posture and EMG), when a work task is transformed from paper-based to VDU-based, can be a risk factor for musculoskeletal complaints. Relevance to industry Computerization of office work is a dominating trend. An increase in postural fixity, as demonstrated in this article, may give rise to musculoskeletal complaints. Insights in mechanisms for their development provide a basis for practical counter-measures, e.g., through the planning of job contents.

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