Most of us don’t think much about the height or the angle of our keyboard. We just sit down and start work. If you spend hours each day at your computer with the keyboard in constant use your hands and wrist are exposed to repetitive stress and strain. Over time this stress and strain can cause chronic problems such as carpal tunnel syndrome and other hand, forearm, and wrist problems. One way to help prevent these problems is to use a keyboard tray.
As with any ergonomic item, the goal is to keep the body in a neutral position. In the case of a keyboard and keyboard tray, this means your wrists, hands, and forearm should not be raised or outside of the neutral position for prolonged periods. To facilitate the neutral position a keyboard tray should do the following.
A keyboard tray should be wide enough and deep enough to hold the keyboard as well as your mouse or any other peripheral accessory device. Your keyboard tray should also be at the proper height for your size. The minimum height adjustment should be between twenty-two inches and twenty-eight inches from the floor.
This helps to keep your arms in the neutral position. You’ll also want to make sure your keyboard tray has the ability to lock into place without having to use a knob to make the adjustment.
Using knobs for locking can be difficult to change once locked into place. Changing to the use of a keyboard tray may require a bit of adjustment t first. Once you get used to the “neutral” position you’ll find it much more comfortable and less of a strain.
Reference: http://www.osha.gov/SLTC/etools/computerworkstations/checklist.html#purchase
