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.

[1]  D Koh,et al.  Anthropometrics and display station preferences of VDU operators. , 1988, Ergonomics.

[2]  M. Polansky,et al.  The Influence of Different Sitting Positions on Cervical and Lumbar Posture , 1996, Spine.

[3]  M. Hagberg,et al.  The effects of different pause types on neck and shoulder EMG activity during VDU work. , 1989, Ergonomics.

[4]  J P Psihogios,et al.  A field evaluation of monitor placement effects in VDT users. , 2001, Applied ergonomics.

[5]  M. B. Villanueva,et al.  Sitting posture and neck and shoulder muscle activities at different screen height settings of the visual display terminal. , 1997, Industrial health.

[6]  L. Straker,et al.  An evaluation of visual display unit placement by electromyography, posture, discomfort and preference , 2000 .

[7]  Jennie P. Psihogios,et al.  The effects of video display terminal height on the operator: a comparison of the 15° and 40° recommendations , 1998 .

[8]  K H Kroemer,et al.  Preferred line of sight angle. , 1986, Ergonomics.

[9]  E Grandjean,et al.  VDT Workstation Design: Preferred Settings and Their Effects , 1983, Human factors.

[10]  Karl H.E. Kroemer,et al.  Fitting The Task To The Human, Fifth Edition: A Textbook Of Occupational Ergonomics , 1997 .

[11]  P M Bongers,et al.  Are neck flexion, neck rotation, and sitting at work risk factors for neck pain? Results of a prospective cohort study , 2001, Occupational and environmental medicine.

[12]  E Grandjean,et al.  Postural and visual loads at VDT workplaces. I. Constrained postures. , 1981, Ergonomics.

[13]  Fereydoun Aghazadeh,et al.  Risk Factors and their Interactions in VDT Workstation Systems , 1996 .

[14]  Arne Aarås,et al.  Work with visual display units: Long-term health effects of high and downward line-of-sight in ordinary office environments , 2006 .

[15]  Carlo J. De Luca,et al.  The Use of Surface Electromyography in Biomechanics , 1997 .

[16]  M Hagberg,et al.  Discomfort and load on the upper trapezius muscle when operating a wordprocessor. , 1986, Ergonomics.

[17]  W Miller,et al.  Display Station Anthropometrics: Preferred Height and Angle Settings of CRT and Keyboard , 1983, Human factors.

[18]  E. N. Corlett,et al.  Evaluation of human work : a practical ergonomics methodology , 1991 .

[19]  R. Burgess-Limerick,et al.  The effect of imposed and self-selected computer monitor height on posture and gaze angle. , 1998, Clinical biomechanics.

[20]  K. H. E. Kroemer.  Computer Work Stations: Preferred Posture and Line of Sight , 1987 .