Adjusting your chair

Seat Height
When seated, your thighs and feet should be horizontal and your knees should form a 90 degree angle.

Seat depth
Sitting back into the chair with your feet flat on the floor, ensure that the clearance between the front edge of the seat and the lower part of the legs (your calves) fits a clenched fist (about 50mm). Pressure on the underside of your thighs can restrict blood circulation.

Backrest
Adjust the backrest forwards and backwards as well as up and down so that it fits the hollow in your lower back.

Armrests
The correct working position is reached when your elbows form an approximate 90 degree angle with your forearms approximately horizontal with the desktop. In this position your arms should barely touch the armrests. In their lowest position the armrests should not lift your elbows, not even slightly.

Workstation/Desk Design

Height
The standard height for a European workstation is 720mm; the “ideal” workstation height, however, depends upon the user and upon the chair and other factors that interact with the user and table. The ideal is for the user to be able to sit at the workstation with the keyboard in place and be able to easily maintain a 90 -100 degree elbow angle and straight wrists while typing.

Leg room
Knee spaces should allow a worker to feel uncrowded and to allow some changes of position. As a general rule you should be able to cross your legs under the workstation in comfort. Knee space should be at least 750mm wide by 500mm deep by 700mm high. For those using a footrest, clearance must be calculated with the legs in place on the footrest.

The worktop
The workstation top should be big enough to allow space, not only for all computer-related equipment, but also for telephone, paperwork, books, and other materials needed while working at the computer. Working with materials scattered on chairs and at odd angles has the potential for neck and other body strain. Frequently used items should be kept close to avoid long reaches. The monitor screen should be at a distance of 450-600mm and the keyboard should be directly in front of the user. A general recommendation is that the work area top should be at least as big as the standard office desk – 1600mm x 800mm. A depth of at least 800mm allows flexibility in use of the work area. Usable space may be maximized with the use of flat screens and good wire/cable management.

Working with a fixed height workstation
Once your chair is properly adjusted for your height, check if you can sit at the workstation comfortably with your legs crossed underneath.

If you cannot fit your legs under the workstation or there is not enough space to move them freely, your workstation is too low for you and you should not use such a workstation on a regular basis!

If you can sit comfortably but need to lift your arms in order to place them over the work surface, your workstation is too high. Adjust the chair height so your elbows are about the same height as the work surface. Use a footrest if you cannot place your feet flat on the floor. The footrest should be adjustable and support both feet. Keep feet flat and firm on the footrest.