Your seat pan should support the full length of your thighs without cutting into your calves. Your back should be fully supported by the backrest of your chair. If your seat pan is too long and you are unable to support your back, you may try using an external full back support to fill the gap.
Ideal seat pan
- Sit with your buttocks at the back of the chair
- Seat pan should support full thighs without cutting into calves
- Space for 2-3 fingers between edge of chair & back of calf
Seat pan too long
The rotating picture above illustrates the differences with the seat pan too long compared to one at the correct length.
- Leaning Forward
If the seat pan is too long it will dig into the backs of the knees causing discomfort. To avoid this discomfort, most people tend to sit at the edge of their chair which results in no back support or they slouch which increases pressure on the lumbar discs.
- Slide seat pan back, or
- Use external backrest to fill gap
Seat pan too short
The rotating picture above illustrates the differences with the seat pan too short compared to one that is the correct length.
- Pressure on the back of the thighs which results in discomfort
- Pull seat pan out, or
- If seat pan is far too short, source chair with longer seat pan
How to Adjust:
Adjustment lever is typically found under the front center or left side