Please try out whatever you are looking at first.
I did try out several chairs including the Hermann Miller aeron chair that was really recommended because of the features. It didn't fit my body.
I ended up with a Swopper ... you can see them on www.sit4less.com on the net. It is like I am sitting on a balance ball only pins will not puncture it. It is adjustable. I feel like it forces me into correct posture. I have it on a throw rug as it doesn't have wheels and I don't want to mar the wood floor.
I do have arthritis and love the extra help I get with this thing.
ali