|
|
Hardware » Books » End-User »
Silicon Graphics Zx10 Visual Workstation Owner's Guide
(document number: 007-4327-002 / published: 2000-09-20)
table of contents | additional info | download
find in page
Appendix A. Ergonomics GuideThis appendix gives you information to help you develop proper work habits, establish a proper work environment, and reduce the risk of injury. Review the information in this appendix before using your computer. Follow these guidelines as you use your computer.
Take the following steps to evaluate and adjust the way you work at the computer.
If you can adjust the work surface or the keyboard support, adjust the chair to rest your feet flat on the floor and to firmly support your thighs with the seat base. Leave the chair at this adjusted position as you go through the following steps.
If you cannot adjust the work surface or the keyboard support, adjust your seating position as described in the following steps.
Rest your fingers on the keyboard.
Relax your upper arms; they should be nearly vertical at your sides. Your forearms should bend nearly at right angles to your upper arms.
If your upper arms are not vertical, adjust the distance between the chair and the keyboard until they are.
If your forearms are not at right angles to your upper arm, adjust the height of the keyboard or the chair until they are.
If your elbows rest on the chair's armrests, do not let this cause you to raise your shoulders from their relaxed position.
Rest your fingers on the keyboard. Your wrists should be straight with your forearms.
If your wrists bend upward or downward, adjust the height of the keyboard or chair to align your wrists properly with your forearms.
If your wrists bend inward or outward, adjust the position of your hands to align your wrists properly with your forearms.
You may find it helpful to use a wrist support for short periods of rest.
Place the monitor screen between 18 inches (45.1 centimeters) and 31 inches (78.7 centimeters) from your eyes (Humanscale, MIT Press).
Angle your head downward slightly when you look at the center of the monitor screen.
If the monitor is too high or too low, use a suitable support to place it at a comfortable height. Do not assume that using the computer's base unit as a support places the monitor at the correct height.
If you continually refer to a document while working at the computer, place the document at the same height and angle as the monitor screen.
The chair you use when working at the computer should firmly support your back when you sit up straight, and your thighs should be at right angles to your torso. The chair should also support the lumbar curve of your back.
If you can adjust the chair's backrest angle, make sure your thighs and your torso are nearly at right angles when your feet rest on the floor.
If you can adjust the chair's backrest tension, make sure it is firm enough to support your back while working. It should only tilt back under force.
If the chair's backrest does not provide lumbar support, use a pad or pillow to provide lumbar support.
When working at the computer, your lower legs should be at right angles to your thighs. Your upper legs should be positioned so the knees are slightly above the hip joint. Your feet should rest flat on the floor.
If your lower legs are not at right angles to your thighs, adjust the chair to be higher.
If your feet do not rest flat on the floor, adjust the chair to be higher. You may need to use a footrest to support your feet and maintain the correct position relative to the keyboard.
If your thighs are compressed on the seat pan, the chair is too high. Some chairs offer a seat pan tilt adjustment for a greater range of lift.
Adjust the room lighting and the position of the monitor screen to minimize screen glare and reflections:
Do not work in an over- or under-illuminated room; an average illumination of 50 foot-candles is usually sufficient. Below this level, you should provide task lighting for documents.
Older individuals may require higher average illumination, up to 100 foot-candles.
Do not work in a cold room. The American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE) recommends the following office climate for the average clothed individual:
Temperature between 73.0 and 79.0 degrees Fahrenheit (22.7 and 26.1 degrees Celsius) during the summer.
Temperature between 68.0 and 74.5 degrees Fahrenheit (20.0 and 23.6 degrees Celsius) during the winter.
Relative humidity between 30 and 60 percent all year.
Reducing the Risk of InjuryThere are several things you can do to reduce the risk of injury while working with a computer.
Do not hold any posture for an extended period of time. If possible, change your working posture several times a day. If you can, work part of the day sitting and part of it standing.
Take periodic rest breaks during the day. A study sponsored by the National Instate for Occupational Safety and Health (NIOSH; R. Henning, University of Connecticut, 1992) found that adding distributed rest breaks to the traditional work schedule “forestall(ed) the development of discomfort in repetitive VDT work.”
Try using this recommended minimum rest break schedule:
30 seconds after each 10 minutes of work.
3 minutes after each 50 minutes of work.
15 minutes at mid-morning.
30 to 45 minutes at lunch.
15 minutes at mid-afternoon.
During each rest break, gently and slowly stretch your hands and arms. During longer rest breaks, get up, walk around, and gently stretch as much of your body as you can. Set a schedule of rest breaks and take them. It is easy to focus on your work and forget to take rest breaks; use a timer or a software reminder program to help you remember.
During each rest break, focus on something far away to relax your eye muscles. Avoid close focus activities like reading during a rest break to allow your eyes to rest.
Keep your hands and arms warm. Warm up and gently stretch your hands before you start working. You may find it helpful to wear warm, fingerless gloves.
Keep a straight, or “neutral,” wrist position. Use wrist rests and other supports during pauses to help you keep a comfortable wrist position.
Use the minimum force necessary to activate switches (of any type, on any device). Many people use far more force than is required; this is frequently true for point-and-drag operations using a mouse. Excess force puts unnecessary strain on tendons, joints, and soft tissues. You may have to teach yourself to use minimum force.
Be aware that home and hobby activities can contribute to any discomfort or pain you may experience at work.
Maintain good overall muscle tone with a sensible exercise program. See a physician for recommendations, or before starting any exercise program.
If you experience any discomfort or pain, evaluate your work habits, your work environment, and your personal activities. Consult a physician if the discomfort or pain persists.
Seek professional medical attention if you experience a problem. Take an active part in alleviating the problem. Do not rely on self-diagnosis.
Silicon Graphics Zx10 Visual Workstation Owner's Guide
(document number: 007-4327-002 / published: 2000-09-20)
table of contents | additional info | download
Front Matter
About This Guide
Chapter 1. Setting Up the Hardware
Chapter 2. Setting Up the Software
Chapter 3. Configuring the System
Chapter 4. Operating the System
Chapter 5. Troubleshooting Operational Problems
Chapter 6. Reinstalling the Operating System
Chapter 7. Gaining Access to System Components
Chapter 8. Upgrading the System
Chapter 9. Servicing the System
Chapter 10. System Hardware and Specifications
Appendix A. Ergonomics Guide
Index
home/search |
what's new |
help
|
|
|
