Correct use of the keyboard is most important. If you are not typing correctly then your incorrect typing techniques can lead to and worsen RSI. Your wrists should be straight as shown below:
Various RSI sufferers have switched to the DVORAK keyboard layout as it relieves the hand action during typing. It may surprise you to learn that the common QWERTY keyboard layout was specifically designed to maximize hand movements and to be most inefficient. The reason being that older typewriters used to get jammed by touch-typists. Unfortunately this convention has continued into the information age.
Fortunately, in the 1920s and 30s two Doctors, Dr. August Dvorak and Dr. William Dealey, designed an alternative layout to minimize hand movements and improve efficiency
Dvorak and Dealey studied letter frequencies and the physiology of the hand and created the layout to adhere to these principles:
It is easier to type letters alternating between hands.
For maximum speed and efficiency, the most common letters and digraphs should be the easiest to type. This means that they should be on the home row, which is where the fingers rest.
Likewise, the least common letters should be on the bottom row, which is the hardest row to reach.
The right hand should do more of the typing, because most people are right-handed.
It is more difficult to type digraphs with adjacent fingers than non-adjacent fingers.
Stroking should generally move from the edges of the board to the middle (as an example, rap your fingers on a table and see which is easier: going from little finger to index or vice versa). This motion on a keyboard is called inboard stroke flow.
Dvorak typists tend to be much faster, both because of ease of typing (70% of keying is on the home row, vs 32% on Qwerty) and because of the reduced error rate on Dvorak due to its ergonomics, but the ease in learning and typing is its greatest advantage.
According to RSI sufferers, the DVORAK layout really does provide benefit as it reduces the overall typing action and evenly distributes the typing load to both hands. However, it is not a cure. Switching to DVORAK is another good way to aid in the recovery of RSI but must be supplemented with other forms of therapies.