Position Chair

Position Chair
How do I keep my Aeron chair from sinking?

I use an Aeron chair at work and its best position is right at the top of its height. After a few hours, though, it always seems to sink a few inches without my adjusting it, requiring me to raise it again a few times every day. Is it just aging, or is there a way to lock it in place?

Lose some weight.

How to Improve Posture : Chair Positions for Improving Posture