These factors make it worse:

Mental reasons: Working at a computer screen often goes together with a increased workload. As well as the fast movements with mouse and keyboard, highly concentrated thought is needed. Usually a lot of information must be processed in a short time. But high-flying thinking combined with repetitive movement is against "human nature", particularly when the information is new. No other organ is so closely connected to the brain as the hand. Thinking processes cause muscle cramp, so the movement must be made against increased resistance. Narrowing of the blood vessels reduces supply to the muscles. On the other hand, even highly automated movements disturb complex thought processes. Typing on a keyboard while formulating a sentence is more exacting and takes place with a reduced supply of blood. Susceptibility to RSI increases under such conditions.


Stress: Work is often carried out under immense time and deadline pressure. Not infrequently, the fear that the task has gotten out of hand plays a role. Anyone under stress cramps up. This cramp spreads out to the neck, shoulders and arm muscles and leads to a 'cramped' attitude to work. Anyone who is a slave to his work will take less care of ergonomic behavior such as correct positioning and operation of devices used, taking breaks, etc. This also increases the risk of RSI.


Working position: A rigid and uncomfortable working position and movement reduces the blood supply to the muscles and can cause minor damage to the muscles and tendons. For example, if you type with two fingers, you concentrate the entire load on these two fingers instead of spreading it across ten fingers as is possible with the ten-finger typing system.  Movement patterns that are not ergonomic include bent or twisted wrists. This narrows the blood vessels and tears tendons and nerves. Injuries and inflammations often result.

The right-angled slab keyboard in common use today almost forces an incorrect position and cramps in the shoulders and neck as well as bent wrists. Working on a laptop also forces a somewhat unhelathy positioning and movement.

It's the speed that does it: Some specialists still believe that typing on an electronic keyboard is less damaging to health than typing on a mechanical typewriter since strokes need less force. This has proven to be wrong. Especially, work at a computer screen has shown that the force required for a movement is less of a problem - it is the high movement frequency that is a principal reason for RSI complaints. The minimization of the force needed to operate an electronic keyboard has enormously increased typing speed, and there is no longer a pause to execute a carriage return or insert a new sheet.

"Personality" risk: Too much orientation towards performance and an excess of ambition often characterize RSI sufferers. Often, they don't pay enough attention to the signals emanating from their own bodies and therefore ignore the first signs of illness.

Operating the mouse: The finger bends, exerts force and either relaxes again or remains in a rigid position lying on the mouse. This operation is carried out innumerable times a day by an operator at a screen to direct the computer mouse. Mouse clicks repeated thousands of times can also lead to the RSI syndrome. Although compared to a keyboard, these repeated one-movement strains are small, this advantage is lost through operating the mouse with too few fingers. Working with this input device is also often connected with higher intellectual demands, such as registering information.