Within the past two years, substantial media attention has been directed at potential adverse health effects of long-term computer use. Renewed concerns about radiation, combined with reports of newly-recognized "repetitive stress injuries" such as carpal tunnel syndrome, have led some to call for regulation in the workplace and others to rearrange their offices and computer labs. There is little evidence that computer use is on the decline, however. On the contrary, more people are spending more time doing more tasks with computers -- and faculty, students and staff at colleges and universities have some of the most computer-intensive work styles in the world.
If, as is widely suspected, health effects are cumulative, then many of us are at risk in our offices, labs, dormitories, and homes. Unfortunately, many years will be required before epidemiological studies can provide definitive guidelines for computer users, managers, furniture suppliers, and office designers. In the interim, individuals and institutions must educate themselves about these issues and protective measures.
One set of issues concerns workstation design, setup, and illumination, together with users' work habits. The City of San Francisco, which recently enacted worker safety legislation, cited research by the National Institute of Occupational Safety and Health (NIOSH) into VDT operator complaints of eyestrain, headaches, general malaise, and other visual and musculoskeletal problems as the rationale for imposing workplace standards, to be phased in over the next four years.
A second set of issues relates to suspected radiation hazards, including miscarriage and cancer. A special concern with radiation is that nearby colleagues could be affected as well, since radiation is emitted from the backs and sides of some terminals. The most recent NIOSH study is reassuring, but some caution still seems prudent.
Ergonomics and work habits
Most people can ride any bicycle on flat ground for a short distance with no problems. On a fifty mile ride over hilly terrain, however, minor adjustments in seat height, handlebar angle, and the like can mean the difference between top performance and severe pain. Similarly, occasional computer users may notice no ill effects from poorly designed or badly adjusted workstations, whereas those who spend several hours a day for many years should pay careful attention to ergonomics, the study
of man-machine interfaces.
The key to most workstation comfort guidelines is adjustability--to accommodate different body dimensions, personal workstyle preferences, and the need to change positions to avoid fatigue. A recommended working posture shows the body directly facing the keyboard and terminal, back straight, feet flat on the floor, eyes aligned at or slightly below the top of the screen, and thighs, forearms, wrists, and hands roughly parallel to the floor. Achieving this posture may require:
A chair with a seat pan that adjusts both vertically and fore-and-aft, an adjustable height backrest, and adjustable tilting tension
An adjustable height work surface or separate keyboard/mouse tray (note that many keyboard trays are too narrow to accommodate a mouse pad, leaving the mouse at an awkward height or reach on the desktop)
A height adjustment for the video display (a good use for those manuals you'll never read!)
An adjustable document holder to minimize head movement and eyestrain
Adjustable foot rests, arms rests, and/or wrist rests.
Studies show that many people are unaware of the range of adjustments possible in their chairs and workstations. Although the best chairs permit adjustment while seated, you may have to turn the chair upside down to read the instructions. (Be careful not to strain your back while upending and righting the chair!) If your posture deviates substantially from that in the diagram--or if you are experiencing discomfort--experiment with adjustments or try exchanging chairs or workstations
with colleagues. A posture cushion, which maintains the natural curvature of the spine and pelvis while supporting the lumbar region, may also prove helpful. It should be noted that any adjustment may feel uncomfortable for a week or so while your body readjusts itself.
Реферат опубликован: 27/01/2008