Doctors say at least one out of every five computer users will develop repetitive strain injury, the painful and sometimes crippling affliction of today's electronic workplace.
RSI can show up suddenly or gradually. Common symptoms include burning, tingling, or numbness (sometimes during the night) anywhere from your fingers to your shoulders. By the time you notice these signs, it's already too late to prevent the problem.
The best way to avoid RSI or reduce the pain is to install safer equipment, and give yourself five-minute breaks twice an hour. But with companies looking to cut costs and increase productivity, it's hard to sell most bosses on the idea.
If you're already in pain, ask a doctor whether you should continue using a keyboard. Assuming you can, lots of small steps can vastly improve the way you feel.
Most experts agree on proper posture: Sit with your screen directly in front of you -- at eye level or slightly lower -- and hold your elbows at right angles to the keyboard. When you type, avoid bending your wrists and twisting hands outward or inward. Apply a gentle touch. Don't slam the space bar or hold thumbs and pinkies tense.
Try not to stretch for function keys and don't operate the "shift" with your weakest finger, the pinkie.
And watch out for wrist rests. Contrary to popular belief, you're not supposed to put your wrists down on them while you're typing, but to let your hands float above. Put your wrists on the padded rest only when you pause to think. Better yet, place them palms up in your lap, and take a deep breath.
To trace your pain to the way you sit or type, consult the book "Repetitive Strain Injury" (John Wiley & Sons, $14.95;  CALL-WILEY). Written by Deborah Quilter, a writer, and Dr. Emil Pascarelli, a physician specializing in RSI, it offers a program for treating and preventing this condition.
An RSI sufferer herself, Ms. Quilter alternates typing with tasks like proofreading, filing, photocopying and attending meetings. She stands up each time her phone rings, using the call as a reminder to loosen up.
Even people with typing-intensive jobs, like word processors and telephone operators, can find ways to interrupt keyboard work, Ms. Quilter says. Stretch on your way to fetch documents from the printer. Put your calendar, frequently used books, paper clips and other tools far enough away that you need to stand up to get them. Walk down the hall to talk with co-workers, rather than using e-mail.
If you use a computer a lot at the office, try to limit repetitive hand motions like needlepoint, knitting, gardening or hammering away in the wood shop after hours. And don't overdo it on those mesmerizing home computers. Instead of surfing the Internet and playing computer games all night, try yoga, walking or swimming to relax.