IMPROVING THE SITTING POSTURE OF CAD CAM WORKERS BY INCREASING VDU MONITOR WORKING HEIGHT

A study was carried out on ten subjects working with computer-aided design/computer-aided manufacture (CAD/CAM) systems to examine the effect of a new position of the VDU monitor on sitting posture. According to a biomechanical study of the neck, the position of the head in which the neck muscle forces are minimal differs from the position of the head when some commonly accepted recommendations regarding sitting posture of VDUs are carried out, and on this basis a direction of view of 15-degrees above the horizontal would be preferable to one of 15-degrees below. By means of continuous recording of the positions of the head and trunk, the effect of this new position of the monitor on sitting posture was examined. Analysis of the results showed that working at a monitor placed in such a position that the direction of view was 15-degrees above the horizontal resulted in a considerably better posture than the former position of the monitor: one is sitting more erect and the head is less bent forward. The active direction of view was 3-degrees above the horizontal. The test subjects did not seem to prefer a greater angle. The results of this test indicate that placing the middle of the monitor at eye level results in a better sitting posture for CAD/CAM workers.