A repetitive strain injury (RSI), also called repetitive stress injury or cumulative trauma, is any of a loose group of conditions from overuse of the computer, guitar, knife or similar motion or tool. It is an occupational overuse syndrome affecting muscles, tendons and nerves in the arms and upper back; hence it is also known as work related upper limb disorder or WRULD. The medically accepted condition in which it occurs is when muscles in these areas are kept tense for very long periods of time, due to poor posture and/or repetitive motions.
It is most common among assembly line and computer workers. Good posture, ergonomics and limiting time in stressful working conditions can help prevent or halt the progress of the disorder. Stretches, strengthening exercises, massages and biofeedback training to reduce neck and shoulder muscle tension can help heal existing disorders.
This is the Wikipedia definition about R.S.I.
I am a doctor, I am aware of this computer related disorder, I also write articles about it.
If U observe this signs it’s probably U have this condition:
1.Recurring pain or soreness in neck, shoulders, upper back, wrists or hands.
2.Tingling, numbness, coldness or loss of sensation.
3.Loss of grip strength, lack of endurance, weakness, fatigue.
4.Muscles in the arms and shoulders feel hard and wiry when palpated.
5.Pain or numbness while lying in bed.
Often early stage RSI sufferers mistakenly think they are lying on their arms in an awkward position cutting off circulation. You should be aware, if some of this signs appears, you might not be able to work and play anymore as before, in front of your PC.
Avoid using the injured hand?
Use your nondominant hand more frequently?
Use your forearm, feet, or shoulder to open doors?
Avoid wearing or buying certain kinds of clothing because it is too difficult to put them on?
Change shopping habits because you can’t carry as much as he wants could?
Keep dropping things?
Find you can’t chop food?
Not play sports you once enjoyed?
Have trouble hooking bras or putting on jewelry?
Not wear bracelets because your wrists are tender?
Have trouble with keys or brushing teeth?
Feel overly protective of your hands?
The effects and reppercusions of R.S.I. are serious, you may be unable to open doors, prepare your own food, do laundry, drive, write, type, and shake hands. RSI can limit your ability to perform at work, this may be the most serious repercussion, your income can be lower than before the appeareance of those signs.
But you can prevent R.S.I.
Good posture is the most important prevention.
Here you can read more about good posture:
Feet: flat on the floor
Knees: directly over feet, bent at right anlges (or slightly greater), with a couple inches of space from the chair
Pelvis: rocked forward, sitting on the “sitz bones,” with hips (the sockets where your femurs attach) positioned no lower than, and perhaps slightly higher than the knees.
Lower back: arched in, and supported by your chair (if it is shaped properly) or a towel roll.
Upper back: naturally rounded
Shoulders, arms: relaxed, at side.
Neck: arched in, relaxed, supported by spine. Be careful not to hold tension in back or under chin.
Head: balancing gently on top of spine.
Correct typing technique and posture, the right equipment setup, and good work habits are much more important for prevention than ergonomic gadgets like split keyboards or palm rests. Note that the chair and keyboard are set so that the thighs and forearms are level (or sloping slightly down away from the body), and that the wrists are straight and level – not bent far down or way back. If the table is too high to permit this, you may do better to put the keyboard in your lap. Also note that the typist is sitting straight, not slouching, and does not have to stretch forward to reach the keys or read the screen. Anything that creates awkward reaches or angles in the body will create problems. Please note that even a “perfect” posture may result in problems if it is held rigidly for long periods of time: relax, MOVE and shift positions frequently. This isn’t just about your hands and arms, either: the use or misuse of your shoulders, back and neck may be even more important than what’s happening down at your wrists.
I think the most important thing in preventing R.S.I. is good posture.