The neutral position putting the least strain on arms and hands at the keyboard is one where the shoulders are relaxed, elbows are loosely at your sides and the forearm and wrist form a straight line," says Thomas Albin, an ergonomist with 3M in St. Paul, Minn.

"You should be able to rest your hands and fingertips comfortably on your key tray and not have to reach and extend your fingers and wrist, which can put some stress at the carpal tunnel region of your hand...at the base of your wrist and hand," says Charles Kopin, an ergonomic specialist for Industrial Health Care in Waterbury, Conn.

Carpal tunnel syndrome, a painful nerve condition causing a loss of grip, is the most serious result of prolonged strain to the fingers, wrists and arms, but earlier symptoms of muscle strain to heed are fatigue, numbness or tingling in the fingers, he says.

Wrist pads, chair armrests, and placement of the mouse within shoulder-width can help prevent these problems, experts say. Ergonomic keyboards and different mouse designs may also help.

Likewise, equipment and tools that people use frequently, like a telephone, should be positioned so that someone doesn't have to reach or twist for them, no more than about 10 to 15 inches away, says Kopin.

Laura Vandendorpe, who had to quit a web-editing job that she loved because of tendonitis, says others must be aware that these problems can occur.

"Don't ignore the warning signs," she says. "Just like when the indicator light goes on in your car and you take it to the shop, if your hands start to hurt, don't ignore it. Re-evaluate how you're working, and it's likely there's something you can fix that can help make the problem go away."