Ergonomic Guidelines for arranging a Computer Workstation Courtesy Cornell University Professor Alan Hedge

Creating a good ergonomic working arrangement is important to protecting your health. The following 10 tips are a brief summary of those things that most ergonomists agree are important. If you follow the 10 tips they should help you to improve your working arrangement. However, every situation is different, and if you can't seem to get your arrangement to feel right or you are confused about some of the following recommendations you should seek professional advice.

10 tips for a good ergonomic workstation arrangement

Work through the following 10 steps to help you decide on what will be a good ergonomic design for your situation:

1. How will the computer be used? If it's one person then the arrangement can be optimized for that person's size and shape, and features such as an adjustable height chair may be unnecessary. If it's several people, you will need to create an arrangement that most closely satisfies the needs of the extremes, that is the smallest and tallest, thinnest and broadest persons. Also think about:
   1. How long will people be using the computer? If it's a few minutes a day then ergonomic issues may not be a high priority. If it's more than 1 hour per day. you need to create an ergonomic arrangement.
      
2. What kind of computer will be used? Ergonomic guidelines for computer workstation arrangements assume that you will be using a desktop system where the computer screen is separate from the keyboard. Laptops are growing in popularity and are great for short periods of computer work. Guidelines for laptop use are more difficult because laptop design inherently is problematic - when the screen is at a comfortable height and distance the keyboard isn't and vice versa. For sustained use you should consider purchasing either an external monitor, an external keyboard, or both and a docking station.
   
3. What furniture will you use? Make sure that the computer (monitor, CPU system unit, keyboard, mouse) are placed on a stable working surface (nothing that wobbles) with adequate room for proper arrangement. If this work surface is going to be used for writing on paper as well as computer use a flat surface that is between 28"-30" above the floor (suitable for most adults). You should consider attaching a keyboard/mouse tray system to your work surface. Choose a system that is height adjustable, that allows you to tilt the keyboard away from you slightly for better wrist posture (negative tilt), and that allows you to use the mouse with your upper arms relaxed and as close to the body as possible.
   
4. What chair will be used? Choose a comfortable chair for the user to sit in. If only one person is using this the chair can be at a fixed height providing that it is comfortable to sit on and has a good backrest. If more than one person will be using the computer, consider buying and a chair with ergonomic features.
   
5. What kind of work will the computer be used for? Try to anticipate what type of software will be used most often.
   1. Word processing - arranging the best keyboard/mouse position is high priority.
   2. Surfing the net, graphic design - arranging the best mouse position is high priority.
   3. Data entry- arranging the best numeric keypad/keyboard is a high priority.
   4. Games - arranging the best keyboard/mouse/game pad is a high priority.
      
6. What can you see? Make sure that any paper documents that you are reading are placed as close to the computer monitor as possible and that these are at a similar angle - use a document holder where possible. The computer monitor should be placed:
   1. directly in front of the user and facing the user, not angled to the left or right, to avoid too much neck twisting. Also, whatever the user is working with, encourage him/her to use the screen scroll bars to ensure that what is being viewed most is in the center of the monitor rather than at the top or bottom.
   2. it should be centered on the user so that the body and/or neck isn't twisted when looking at the screen. However, if you are working with a large monitor and spend most of your time working with software like MSWord, which defaults to creating left aligned new pages, and your don't want to have to drag these to more central locations, try aligning yourself to a point about 1/3rd of the distance across the monitor from the left side.
   3. it should be placed at a height that doesn't make the user tilt their head up to see it or bend their neck down to see it. When your seated comfortably, a user's eyes should be in line with a point on the screen about 2-3" below the top of the monitor. We see more visual field below the horizon than above this, so at this position the user should comfortably be able to see more of the screen. If the monitor is too low, the user will crane their neck forwards, if it's too high they'll tilt their head backwards and end up with neck/shoulder pain.
   4. it should be at a comfortable horizontal distance for viewing, which usually is around an arms length (sit back in your chair and raise your arm and your fingers should touch the screen). At this distance you should be able to see the viewing area of the monitor without making head movements. If text looks too small then either use a larger font or magnify the screen image in the software rather than sitting closer to the monitor.
   5. in some instances and for some users, such as those who wear bifocal corrective glasses, the monitor should be tilted backwards and the height adjusted for comfortable screen viewing.
   6. If any adjustments feel uncomfortable then change them until the arrangement feels more comfortable.
      
7. Posture, posture posture! Good posture is the basis of good workstation ergonomics. Good posture is the best way to avoid a computer-related injury. To ensure good user posture:
   1. Watch the user's posture!
      1. Make sure that the user can reach the keyboard keys with their wrists as flat as possible (not bent up or down) and straight (not bent left or right).
      2. Make sure that the user's elbow angle (the angle between the inner surface of the upper arm and the forearm) is at or greater than 90 degrees to avoid nerve compression at the elbow.
      3. Make sure that they upper arm and elbow are as close to the body and as relaxed as possible for mouse use - avoid overreaching. Also make sure that the wrist is as straight as possible when the mouse is being used.
      4. Make sure the user sits back in the chair and has good back support. Also check that the feet can be placed flat on the floor or on a footrest.
      5. Make sure the head and neck are as straight as possible .
      6. Make sure the posture feels relaxed for the user.
   2. Keep it close!
      1. Make sure that those things the user uses most frequently are placed closest to the user so that they can be conveniently and comfortably reached.
      2. Make sure that the user is centered on the alphanumeric keyboard. Most modern keyboards are asymmetrical in design (the alphanumeric keyboard is to the left and a numeric keypad to the right). If the outer edges of the keyboard are used as landmarks for centering the keyboard and monitor, the users hands will be deviated because the alphanumeric keys will be to the left of the user's midline. Move the keyboard so that the center of the alphanumeric keys (the B key, is centered on the mid-line of the user).
      3. make sure that the phone is also close to you if you frequently use it.
   3. A good workstation ergonomic arrangement will allow any computer user to work in a neutral, relaxed, ideal typing posture that will minimize the risk of developing any injury.
      
8. Where will the computer be used? Think about the following environmental conditions where the computer will be used.:
   1. Lighting - make sure that the lighting isn't too bright. You shouldn't see any bright light glare on the computer screen. If you do, move the screen, lower the light level, use a good quality, glass anti-glare screen. Also make sure that the computer monitor screen isn't backed to a bright window or facing a bright window so that there's the screen looks washed out (use a shade or drapes to control window brightness).
   2. Ventilation - make sure that you use your computer somewhere that has adequate fresh-air ventilation and that has adequate heating or cooling so that you feel comfortable when you're working.
   3. Noise - noise can cause stress and that tenses your muscles which can increase injury risks. Try to choose a quiet place for your workstation, and use low volume music, preferably light classical, to mask the hum of any fans or other sound sources.
      
9. Take a break! All ergonomists agree that it's a good idea to take frequent, brief rest breaks: Practice the following:
   1. Eye breaks - looking at a computer screen for a while causes some changes in how the eyes work, causes you to blink less often, and exposes more of the eye surface to the air. Every 15 minutes you should briefly look away from the screen for a minute or two to a more distant scene, preferably something more that 20 feet away. This lets the muscles inside the eye relax. Also, blink your eyes rapidly for a few seconds. This refreshes the tear film and clears dust form the eye surface.
   2. Micro-breaks - most typing is done in bursts rather than continuously. Between these bursts of activity you should rest your hands in a relaxed, flat, straight posture.
   3. Rest breaks - every 30 to 60 minutes you should take a brief rest break. During this break stand up, move around and do something else. Go and get a drink of water, soda, tea, coffee or whatever. This allows you to rest and exercise different muscles and you'll feel less tired.
   4. Exercise breaks - there are many stretching and gentle exercises that you can do to help relieve muscle fatigue. You should do these every 1-2 hours.
   5. Ergonomic software - working at a computer can be hypnotic, and often you don't realize how long you've been working and how much you've been typing and mousing. You can get excellent ergonomic software that you can install on your computer. The best software will run in the background and it will monitor how much you've been using the computer. It will prompt you to take a rest break at appropriate intervals, and it will suggest simple exercises.
      
10. What about ergonomic gizmos? These days just about everything is labeled as being "ergonomically designed" and much of the time this isn't true and these so-called ergonomic products can make things worse. If you're thinking about buying an "ergonomic product" as yourself the following 4 questions:
    1. Does the product design and the manufacturer's claims make sense?
    2. What research evidence can the manufacturer provide to support their claims? Be suspicious of products that haven't been studied by researchers.
    3. Does it feel comfortable to use the product? If it doesn't then don't use it!
    4. What do ergonomics experts say about the product? If they don't recommend it don't use it.
       
       There are many computer-related "ergonomic" products, the most common ones being:
    5. "ergonomic" keyboards - most of these are keyboards where the alphanumeric keys are split at an angle. For a non-touch typist this design can be a disaster! The split design only addresses issues of hand ulnar deviation, and research studies show that vertical hand posture (wrist extension) is more important. There is no consistent research evidence that most of the split-keyboard designs currently available really produce any substantial postural benefits. For most people a regular keyboard design works just fine if it's put in the proper position.
    6. "ergonomic" mouses - many of these mouse designs or alternative input device designs can work well to improve your hand/wrist posture. However, it's important to check that you can use these with your upper arm relaxed and as close to your body as possible. Overreaching to an "ergonomic mouse" defeats any benefits of this design.
    7. Wrist rests - these were very popular a few years ago, but research studies haven't demonstrated any substantial benefits for wrist rests. If you choose to use a wrist rest a broad, flat surface design works best. Avoid soft and squishy wrist rests because these will contour to your wrist and encourage wrist-twisting movements. Your hands should be able to glide over the surface of a wrist rest during typing.
    8. Support braces/gloves - There is no consistent research evidence that wearing wrist supports during computer use actually helps reduce the risk of injury. If you do like wearing a wrist support make sure that it keeps your hand flat and straight, not bent upwards. There is some evidence that wearing wrist supports at night in bed can help relieve symptoms for those with carpal tunnel syndrome.

The above 10 tips give a brief summary of good ergonomic design practice for computer workstations, but there's lots more to consider. You can read about ergonomics in many books, you can browse other materials on this CUErgo web site, you can get information from the Human Factors and Ergonomics Society, and you can ask expert ergonomists for help and advice.

If you have any questions or comments about the information on this page or this web site you can send these to Professor Alan Hedge at Cornell University.

Happy computing!

Note that all materials on this page and web site are copyright and may not be copied or distributed without permission.
© Alan Hedge, 2/6/99