Keying technique on computers can vary depending on many factors. Among these are your seated posture, the desk height, the distance of the keyboard from your body, the angle of the keyboard, and if a wrist-rest is used.
One fact to bear in mind if you choose to use a wrist rest, is that the pressure inside the carpal tunnel is magnified by two (Cornell University) if you place your wrist palm-side down on a wrist rest and it comes in contact (actually rests) on the device. However, if you do not use a wrist rest your arms, wrists and hands may fatigue quickly. Either situation can contribute to risk for Carpal Tunnel Syndrome. Quite a puzzle!
As far as work technique goes, you are better off if you use the wrist rest only while you are actually resting and lift your hands when you key, so that the fingers drape softly over the keys - reaching or stretching of the fingers is minimized. Then, when you are pausing to think or waiting for the CPU to process something, sit back, relax your shoulders, neck and arms, and allow the palms to take the majority of the weight as they rest on the wrist-rest.
Be sure to examine the wrist rest carefully in relationship to your work area. Make sure the height of the wrist rest is slightly lower than the height of your space-bar.
In choosing a wrist-rest it is best to aim for one that will provide the least pressure possible on the carpal tunnel. With this in mind, many companies have designed gel filled or gel layered wrist rests. Avoid wrist rests wtih sharp edges. Make sure the wrist rest is only as long as your keyboard.
If you must use a wrist-rest while mousing, use a separate one that can be positioned so that it provides the least interference with your mouse motion. Another article will discuss mouse wrist rests in more detail.
Newer wrist-rest innovations include some with small particles in them such as the ergo-beads wrist rest by Imak. The theory behind these is that although pressure may be increased within the carpal tunnel, the size of the particles is such that there is never increased pressure across the whole of the tunnel Ė there are always places where the tunnel is not impacted.
There are also memory-foam wrist-rests. Memory foam by itself may be problematic. It tends to sink where weight is placed and harden there. It is slow to return to its original shape. Memory foam will tend to hold your hand in the position it falls into. This may negatively impact your keying technique by limiting mobility. A layered foam wrist-rest may work, but please try it out for a day or two before deciding to purchase one.
Another item to consider is the roller mouse, or track-bar mouse. This imbeds a highly functional mouse alternative in the middle of the wrist rest area. For some people, these are wonderful solutions. (They work especially well for those with reaching or shoulder problems.) For others, they donít work so well. These are items you should definitely try out before purchase.
Because ergonomics looks at the individual and their relationship to the work area, there is no one best solution. What works for you may not work for your friend. Best, have an ergonomist examine how you work in your work area and make suggestions from observation. Next best, borrow different types of items and try them out for a couple of days apiece. Find out what seems to work best for you. Following the precaustions in this article, you will most often be able to tell what fits your style and your body - however, if the wristrest is very different than what you have had in the past, it may take several days to get used to it.
Ergobeads Wrist Rest (Imak)