A must read: Computers can wreck your health. Part 2

Yesterday I paraphrased guidelines developed by Dr Alan Hedge, Professor, Ergonomics, Cornell University for creating a good ergonomic working arrangement.

Good posture is the basis of good workstation ergonomics and is the best way to avoid a computer-related injury. And proper workstation arrangements, good lighting and ventilation, regular breaks, and the odd useful ergonomic gizmo will add to your wellbeing.

Today, reading Dr Hedge’s guidelines on these topics will help save you from disc compression and poor health generally.
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Posture

• Make sure that you can reach the keyboard keys with your wrists as flat as possible (not bent up or down) and straight (not bent left or right).

• Make sure that your 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.

• Make sure that the 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.

• Be sure to sit back in the chair and have good back support. Also check that the feet can be placed flat on the floor or on a footrest.

• Make sure your head and neck are as straight as possible .

• Make sure your posture feels relaxed.

Keep things close by

• Make sure that those things you use most frequently are placed closest to you so that they can be conveniently and comfortably reached.

• Make sure that you are 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).

• Make sure that the phone is also close to you if you frequently use it.

Lighting and ventilation

• 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).

• 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.


Take frequent breaks

• 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 from the eye surface.

• 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. During a micro-break (< 2minutes) you can briefly stretch, stand up, move around, or do a different work task e.g. make a phone call).

• 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.

• 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.

Ergonomic gizmos

• 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. For most people a regular keyboard design works just fine if it's put in the proper neutral position.

• 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.

• Wrist rests - these were very popular a few years ago, but research studies haven't demonstrated any substantial benefits for wrist rests. In fact, a wrist rest can actually increase pressure inside the carpal tunnel by compressing the undersurface of the wrist (take a look at your wrist and you'll probably see blood vessels that shouldn't be compressed!). If you choose to use a wrist rest, using one with a broad, flat, firm surface design works best, and rest the heel of your palm on this NOT your wrist.


So there you have it. It does seem that there’s not much time left to work on the computer if you follow all these guidelines! However, do what most people do and find a happy medium in your work practices that keeps you healthy.

The full version of this information can be found at: http://ergo.human.cornell.edu/ergoguide.html

 

Very helpful. I was able to pinpoint my problem. Ulnar nerve compression. Great huh. Found some info on what to do so this does not get worse, hopefully I do not need to get surgery. Again, thank you for the information.

 

I'm well past computers ruining my health.
There comes a point where we must accept it and move on

 

Hmmm .... i'm lying on my stomach, on the couch, propped up with a pillow, the notebook is sitting on a coffee table (same height as the couch) at the end of the couch.

My head is almost 90 degree's up from my body (ie neck bent back), pillow and elbows are propping me up and enabling me to type on the notebook keyboard.

Do you think I'm doing anything wrong?

 

Nope, your posture is A-ok

Can you post a pic of this role model position?

 

I would if I could get up...my arms have gone numb from the shoulders down, I've got this sharp pain in the small of my back, and my neck is killing me, oh and my big toe on my right foot has gone to sleep!

Not to mention my eyes, not sure whats happening there, I've only been working at the computer with the lcd less than a foot away for like 8 hours non stop, I can usually go at least 14 before my eyes go funny.

 

Thank you
i would try to practice