The Ideal Work Station:
Guidelines for Computer Station Equipment and Set-Up

Adjusting the Work Station

With this ideal combination of equipment and furniture, the following adjustment procedure is recommended for maximum comfort and protection against the development of cumulative trauma disorders.

Avoid glare

Windows should be to the side of the work station, neither behind nor in front of the operator. Ceiling lights should be to either side of the operator, not directly behind. Even the best "glare screen" is ineffective against poor light placement. Dim general lighting supplemented with adjustable task lighting is ideal. Sometimes removing half of the bulbs or installing "egg crate" covers in overhead fluorescent lights can help reduce glare.

Align work station components

The chair, keyboard, and monitor should be moved into a straight line. This will help keep the neck and wrists straight.

Adjust the height and angle of the seat

Adjust the height of the chair before anything else; it is this height to which all other adjustments relate (assuming that the keyboard height can also be adjusted to match). Feet should be comfortably flat on the floor, with the seat pan low enough so that its front does not cut into the back of the knees. The usual recommendation is that the back of the knee, while standing, should be 2" above the top of the seat pan; this can vary somewhat according to comfort. A tilting seat pan can be tilted forward to reduce pressure on the back of the knees.

Adjust arm rests

Adjust the height of the arm rests so that they support the shoulders in a relaxed, neutral posture, avoiding hunching or drooping to reach the rests. Pull the arm rests comfortably close to the body. Ideally, the arm rests can easily swing out of the way when the operator leaves or enters the chair. Once seated, always pull them close.

Adjust keyboard tray height

Adjust the height of the keyboard tray so that the forearms are roughly parallel to the floor, or with hands slightly lower than your elbow. Elbow angle should be 90° or more, depending on comfort. Some evidence suggests that an elbow angle of 110° to 120° can reduce stress on the ulnar nerve.

Adjust keyboard tray angle

Adjust the tilt of the tray so that the wrists are in a neutral posture, without bending up or down. Usually, a negative tilt (tilting away from the operator) is needed to achieve this posture. This adjustment may require a slight re-adjustment (usually down) of the keyboard height. Avoid using the prop-up legs in the back of many keyboards.

Adjust the monitor height and angle

Adjust the height of the monitor so that the top of the screen is roughly even with eye level. This reduces the need to lean the head forward or tilt it back to view the screen. The goal is to balance the weight of the head on the spinal column, reducing muscle force needed to keep the head upright. Ideally, the monitor screen should be perpendicular to a line from the operator's eyes to the screen. Slight adjustments to this angle are acceptable, in the interests of reducing glare.

Increase type size

Whenever possible, increase the size of the type (for word processing) or the objects (for programming, graphics work, etc.) on the screen. In many CAD programs, objects can be enlarged to fill most of the screen. This accomplishes the dual purpose of reducing eye strain and reducing wrist and finger strain due to small mouse movements.

Activity breaks

Real breaks (e.g., breaks that involve different muscle groups and remove the eyes from a monitor screen) should be taken every hour, for at least 5 minutes. Research results about the value of stretching exercises are contradictory, but they will not be harmful.

See also:

The Ideal Work Station: Equipment and Furniture

The Ideal Work Station: Temporary Measures