Office Chairs
It is essential that office seating is comfortable, appropriate to the task being undertaken and easy for the operator to adjust. The often held view of the activity of sitting is that people maintain a fixed posture for long periods of time, however, when performing a range of activities, people tend to adopt different positions and postures while seated. This is desirable as it provides variation in loading of the thighs and back and in general can improve seating comfort.
Adjustable office chairs
A chair is the main item of a workstation that provides adjustability for comfort and enables the work heights to be controlled. Key factors to consider when determining if the chair is appropriate for the person and the job are listed as follows:
- it should be adjustable to the task and be easily adjusted from the seated position;
- the seat should be height-adjustable, preferably utilising a gas lift for ease of adjustment;
- the seat should have a curved front edge, to minimise pressure on the underside of the thighs (see illustration);
- the seat should be able to tilt slightly backwards or forwards;
- it should have a supportive backrest that is adjustable in height, angle and depth;
- both the seat and backrest should be covered by cloth or some other type of material that breathes;
- it should have a five-star base for stability; and
- armrests are optional; they help decrease the forces on the shoulders and back during rest from keying. If provided, armrests should preferably be adjustable in height.
In general, chairs are designed to fit 90% to 95% of the adult population. People outside this range, because they are tall, short or large, may need seating that is tailored to their needs.
Chairs should support the body in a way which minimises awkward postures and provides comfort, however, chair positions may need to be changed often. No chair can provide a perfect position for long periods and it is important to change postures and get up from a chair many times during the day’s work. Setting up an adjustable chair for optimum support is shown in Setting up your office chair.