Zenith Insurance Company: Designing an Ergonomically Sound Workstation

Ergonomics is the science of fitting jobs to people. Work environments that allow workers to operate more comfortably without excess physical and mental stress improve productivity, work quality, job satisfaction and attitude. Designing an ergonomically sound workstation often involves repositioning the work or the worker. These simple changes usually represent little or no cost.

To learn more about adjusting your workstation to fit you, move your cursor around the scene below. Don't forget to take a break.

This section considers the pros and cons of providing armrests on office chairs.

ARE ARMRESTS NEEDED FOR OFFICE CHAIRS?

QUESTION:

Should an office chair be outfitted with armrests?

ANSWER:

It depends on at least these factors -

The type of task (or set of tasks) being performed.
Potential interference with the work surface.
The design and adjustability of the armrests in question.
Preferences and characteristics of the person being fitted.

ARMREST PROS

When properly fitted with the worker, the task and the workstation:

Those with age or injury related strength or stability issues may benefit from use of armrests while entering and exiting a chair.
Resting the weight of the arms can reduce neck and upper back muscle activity. Even if not used continuously, some people benefit from occasional or intermittent armrest use.
Support from an armrest can improve performance for certain types of precision tasks.

ARMREST CONS

Increased reach distance due to interference between armrests and desk/work surface/keyboard tray height and armrest height. This problem alone often makes the use of armrests worse than better.
Using armrests to support body weight, rather than just arm weight.
Potential for contact pressure on the forearms and bony parts of the elbow or wrist.
Chair armrests often are not adequate for computing tasks because they don't have a suitable amount of surface area and range of motion to support the arms through the range of movement required for keyboard and mouse use.

QUICK GUIDELINES: WHEN ARMRESTS ARE INCLUDED

If armrests are present they should be designed such that they:

Do not reduce access or increase reach distance to the desk/work surface/keyboard tray.
Are adjustable through a range that can take them below or away from any work surface interference.
Are adjustable and sized such that they can drop below a user's resting elbow height and not extend past their abdomen.
Are adjustable and sized to be wide or narrow enough to comfortably accommodate the person's body width.
Are easily detachable in case they create interference, are not used, or are disliked.

QUICK GUIDELINES: WHEN ARMRESTS ARE NOT INCLUDED

Situations in which armless chairs might be specifically recommended over a chair with adjustable armrests include:

If a person has a habit of leaning (with body weight, not just the weight of the arm) on the armrests, and therefore has contact pressure and biomechanical problems.
If the person has expressed a preference for an armless chair and demonstrates good sitting and computing habits.
If the cost savings allows them to purchase a quality chair that fits them well in every other regard.