Effects of computer monitor setting on muscular activity, user comfort and acceptability in office work

This paper presents the results of a study to investigate the effect of computer monitor height on the neck muscle activity, user comfort and user acceptability for office based tasks in the seated posture. Ten subjects with intermediate level of computer-skill participated in the study. Three computer monitor height settings- high, medium and low representing respectively angles of sight of 15 degrees, 30 degrees and 45 degrees below the horizontal at eye level were considered. Electromyography recordings from the right and left upper trapezius muscles were obtained for each monitor placement. The ratings of user comfort and acceptability were also obtained for each of the monitor settings. Statistical analysis of muscular activity data showed that there was no statistically significant difference between the mean RMS values for the three monitor settings. Results of the study indicate that the overall comfort was significantly more for high monitor setting than for the medium and low settings. It was also found that the comfort ratings for the neck and the low back regions were significantly higher for the high monitor setting compared to the low setting. Data analysis of user acceptability ratings for different monitor positions showed that the high monitor setting was significantly more acceptable than the medium and the low settings.