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

Equipment and Furniture

An ideal computer work station requires a combination of equipment and furniture that is the right size and design and is easily adjustable. The components of this ideal work station are:

A desk surface that is deep enough for the depth of the monitor

For many of the modern 17" monitors, a 30" desk surface is needed if the desk is not free standing (for example, in modular office set-ups, where the desk surface is suspended from a vertical divider panel). If the desk is free standing, the back of the monitor can project beyond the desk edge, allowing the use of a narrower surface.

A keyboard tray with 3 adjustments

The adjustments should be independent, easily accomplished, and stable (i.e., the tray should not easily slip out of the set positions).

• A forward slide that brings the keyboard fully beyond the overhanging desk top. If this slide is long enough, it may allow the use of a narrower desk top for the monitor. The tray must lock easily in the extended position.
• Vertical adjustment
• Forward and backward tilt

Height-adjustable work tables are also available that allow alternation between seated and standing positions through the day.

A mouse tray with vertical and horizontal adjustment

The mouse should be at the same height as the keyboard and as close as possible to the left or right end of the keyboard (depending on handed-ness of the operator). Fixtures are available that fit over the numeric keypad; these are recommended if the operator does not use this keypad often. The goal of mouse tray use is to reduce the shoulder, arm and hand motions required in shifting between keyboard and mouse. The mouse tray also reduces the need for sustained reaching postures.

There are alternative devices, such as pens, touch-sensitive pads and trackballs, to replace the mouse. Although good research is not yet available, these may reduce the risk of hand problems due to mousing. With any of these, the same basic guideline should be followed: keep the device as close as possible to the keyboard.

A monitor lift which is counterbalanced to allow easy vertical adjustment of the monitor

A chair with the following adjustments

These adjustments should be easy to carry out from a seated position:

• Seat height
• Seat pan depth (seat slides front to back) to accommodate different thigh lengths
• Seat pan tilt, to allow changes in pressure points and relieve possible pressure on the back of the legs (This is of particular importance if a non-adjustable keyboard height requires the chair to be higher than the optimum height specified below.)
• Lumbar (lower back) support, adjustable both in height and in tilt. The tilt mechanism should operate independently of the seat pan tilt mechanism. It should allow for both free movement (with adjustable spring tension) and fixed position at any selected point. We recommend that this angle be varied from time to time during the work day.
• Well-padded arm rests that are adjustable both vertically and horizontally (so they can be brought close to the body). This horizontal adjustment is particularly important for smaller operators, who may have to hold their elbows well away from the body to use fixed arm rests. These arm rests remove static load from the shoulders and eliminate the need to use a wrist rest for support. It is best to have arm rests that are short enough that they do not interfere with pulling the chair close to the keyboard.

Foot Rest

A foot rest is not needed, if the work station can be properly adjusted. It is only to be used at a work station where proper chair height adjustment cannot be achieved and the feet cannot rest flat on the floor.

Copy Holder

Choose a model that supports multiple page documents close to the monitor screen. It is best to have the copy holder attach directly to the top or side of the monitor. This allows the copy to be next to the screen, reducing the need to twist the neck to look at the copy.

A small, adjustable, incandescent task light

The illumination level and light placement can be changed to reduce glare and make the copy illumination level roughly equal to that of the screen. These measures reduce eye strain.

Headsets

Headsets reduce neck strain from cradling a telephone between ear and shoulder while working on a computer. Models are available that are attached directly to the telephone or that use a wireless transmitter, thus allowing the operator to move away from the telephone.

Good Computer Equipment

High resolution monitors, with a short refresh rate and anti-glare coatings can do a lot to reduce eye strain. Larger monitors also tend to be easier to read, although you can also adjust the visual display on most monitors to give a larger font size. Split keyboards in theory should help to reduce the side bending angle (ulnar deviation) of your hands, though there is at present no firm evidence that they reduce injuries.

Eyeglasses

Prescription requirements for glasses change with age. Even an appropriate prescription for normal activities of living can cause eye strain if it is not set for the focal length of the eye to the monitor. Bifocals may force wearers to tilt their heads back to see the monitor clearly, causing neck strain. Most opticians can make recommendations for prescriptions for computer users--single-focus computer glasses, different positioning of the bifocal areas, etc.

See also:

The Ideal Work Station: Adjusting the Work Station

The Ideal Work Station: Temporary Measures