The chair – How do I sit correctly at the computer workplace?
Familiarise yourself with the settings of your chair. Each adjustable office chair comes with an instruction manual that is often attached below the seat surface. The following steps guide you to a good posture.
It is best to adjust the chair freely in the room, free from a desk. The described sitting posture is ergonomically favourable, but it is not meant to be constantly held for long periods. A continuously rigid posture is unfavourable.
So, it is best to sit dynamically; change your sitting posture and stand up now and then. Dynamic sitting prevents cramping of the muscles. Moving, loose muscles promote blood circulation which is anyway impaired by prolonged sitting. By avoiding constant sitting you can prevent varicose veins, phlebitis and thrombosis, and can counteract fatigue.
How do I use the backrest
This is the correct leg position
The right angle for the knee joints
The angle of the knee joint is approximately 90° or slightly more. If the angle is smaller, you are sitting too low and the seat can no longer support your thighs. If the angle is much larger, the pressure on the blood vessels in the thighs increases; the blood flow is impaired.
The seat should be adjusted
If you sit on the chair all the way to the back, an adjustable seat is positioned. Approximately a space four-fingers wide exists between the back of the knees and the front edge of the seat. If the seat pushes into the back of the knees, this can lead to poorer blood flow in the legs. If the distance between knee pit and seat is too large, the thigh cannot be supported and the leg muscles in the long run are more strained.
The correct position of the armrests
If your chair has armrests, adjust them in height so that the arms are supported at a right angle. When adjusting, watch out that you do not raise your shoulders, otherwise muscle tension will occur in your shoulders and neck.
The backrest should be moveable
The backrest has to remain adjustable.
Take advantage of the flexibility of the individually adjustable chair. For this the backrest should not be fixed and locked. Adjust the flexibility of the backrest so that it follows the individual movements of your back. In leaning back, you should not fall back (the backrest is too lightly adjusted); you should not be pushed forward when you lean back (the backrest is adjusted too tightly). Sometimes it takes a while to find the favourable setting. Only with a flexible backrest can you adopt various postures and are able to sit dynamically. This is important to avoid pressure on your intervertebral discs.