1.Line of Sight
Close your eyes and open them slowly, you should be looking at the center of your monitor screen. If the position of the monitor is too high or too low, make necessary adjustments to reduce the strain on your neck.
Upon sitting comfortably, the closer the elbow is to the table, the better it is. This is to ensure that the upper arm is parallel to the spine. Place your hand on the surface of the work desk (such as a notebook or keyboard) and adjust the height of seat to ensure that the elbow is at a right angle.
At the same time, adjust the height of the armrest so that the upper arm happens to be slightly raised at the shoulder.
3.Lower Back Height
Do not cuddle up in the chair when you feel tired. This will add extra pressure to your lower back and intervertebral discs.
Position your hips against the back of the chair, it is advisable to put a cushion so that your back can bend a little. When you are tired, your body will not cuddle up, and you can minimize the burden on your back.
Check whether your fingers can slide freely in between the thighs and front edge of the chair. If the space is too tight, you need to add an adjustable footrest to support your thighs. If there is a finger’s width between your thighs and the front edge of the chair, then you must raise the height of the chair.
Calf: Position your hips against the back of the chair, try to clench your fist and check whether your fist can go through the gap between the calf and front edge of the chair.