The legrests enable the user to relax both legs. The legrest should be adjusted in such a way that when it is moved upwards the legs will never overextend.
The best way to relax is to make use of the so-called tilt-in-space adjustment. In this situation, both the seat and the backrest are tilted backwards. This drastically reduces the strain on the back, which feels extremely comfortable. The greater the backward tilt, the better.
For many chairs, only the backrest can be adjusted backwards. However, this is not good for the user because the seat angle then becomes too great. In this situation there is a tendency to start slouching, with all the resultant negative effects. More information on the subject can be found in ‘Effects of the wrong kind of sitting’.
When someone is lying down, the pressure on the spine largely recedes and there is little strain on the back. This is necessary for the intervertebral discs to recover. Even better is a posture where the legs, when bent, are higher than the heart. This is known as the ‘zero gravity’ position.
This almost strain-free posture helps the muscles relax and stimulates circulation of the blood. The lying position is attained by first tilting the armchair backwards and then adjusting the backrest backwards. In this position no shear forces will develop.
A person is most easily able to get up out of a chair which suits their physique. If this still presents a challenge because of reduced muscle strength, the chair itself might help.
A rise function on a chair can secure riser-recliner function. With one push of a button, the user will, as it were, be raised out of the chair. One important safety condition is that the riser-recliner chair moves backwards and not forwards during the rising motion. Fitform armchairs all come with a secure rise function.