Although it often seems as if personal computers have been around forever, they are still less than two decades old.  Unfortunately, as the electronic information age has advanced, so too have concerns and complaints about working with computers. This guide provides an overview of the basic information needed to ensure a safe and comfortable computer workstation.  By a combination of proper design and appropriate work habits, it is possible to virtually eliminate the risk of acquiring repetitive motion disorders associated with keyboard work. And don�t just restrict these guidelines to your work � keep them in mind for home as well.

Musculoskeletal problems occurring with computer use may range from simple muscle fatigue or neck and back ache to cumulative trauma disorders. Cumulative trauma disorders are associated with tasks that require repetitive motions occurring over long periods of time. The two that may be experienced by keyboard users include Tenosynovitis and Carpal Tunnel Syndrome (CTS). Tenosynovitis is an inflammation of the sheaths through which the tendons of the fingers pass. It is caused by rapid flexing of the fingers and wrists. Symptoms are pain in the wrist and back of the hand. Tendonitis, an inflammation of the tendon itself, may also be a problem for computer users. Carpal Tunnel Syndrome is a condition caused by compression or squeezing of the median nerve which passes through the carpal tunnel of the wrist bones. Pressure on the nerve causes numbness, tingling, burning or pain in the palms, fingers or wrists. The problem can intensify over time, spreading up the arm and weakening the muscles, so that one may drop objects being carried or fail to sense hot or cold. CTS can be aggravated by swelling of the tendon sheaths such as in tenosynovitis.

Musculoskeletal complaints involving muscular fatigue or cumulative trauma disorders are usually the result of the following conditions:

• Maintaining an unnatural or unhealthy posture while using the computer.

• Inadequate lower back support.

• Static load placed on the body by sitting in the same position for an extended period of time (i.e., turning head to the side to view poorly placed document).

• An ergonomically poor workstation design.

The control of musculoskeletal problems can be accomplished by utilizing the ergonomic potential of your work station. Furniture, unit design and proper technique often go hand-in-hand. The following are descriptions of desirable features for furnishings and equipment, their setup, and the proper technique to be used with each item.

1. Keyboard support surfaces should be wide enough (minimum ~30 inches) to accommodate the keyboard and the mouse. An alternative is to utilize two separate surfaces, e.g., a keyboard and a mouse tray which are the same height.

2. Keyboard height should generally be between 28 and 30 inches such that the keyboard height is approximately equal to seated elbow height and forearms are roughly parallel to the floor with elbows bent 90 degrees. Adjust chair height to accommodate this elbow/forearm position and utilize a foot rest if necessary.

3. Computer table should be as thin as possible to allow plenty of thigh clearance. (Standard desks do not make good computer tables because the height is too tall and the desk because of the pencil drawer, is too thick).

4. Elbows should be at sides with shoulders relaxed.  Keyboard should be pulled close to body.

5. Wrists should be flat over the keyboard. Wrist rests which are approximately the same height as the keyboard space bar may assist in keeping wrists in this neutral, flat position. Lowering the back legs on the underside of the keyboard may also help keep wrists neutral while typing.

6. Arms and wrists should not be rested against a hard and/or sharp surface. Wrist rests can be used to provide a padded, soft surface to rest the wrists.

7. Move whole hand to reach distant keys; don't stretch hand. Utilize the wrist rest only when not typing so that you move your hands when reaching for keys.