There is no ability to adjust arm support height or knee/floor height other than to deflate the ball so much it loses its purpose. The fact that the ball definately forces you to engage your core muscles is what keeps the rating @ a 3.
I don't believe I'd recommend this chair based on the lack of real ability to adjust for different body dimensions.
I had purchased just a ball but could not get one large enough as I was looking to use it as a desk ball. I found this chair and thought why not??? It was not too difficult to put together. It's lightweight. I am not sure I am crazy about the arms other than using it for getting up and down but the back support is awesome. Reasonably priced too.
After several months of lower back pain, I learned through visits with various specialists that I just had weak muscles in my core. After one week on the ball chair, I'm already feeling like me again! I've also noticed my posture is better overall - even in seating where people typically slump.
How accurate was the sizing? The chair is a little smaller than expected, but fits me perfectly. A couple of male colleagues don't fit in the chair well. It's not made for someone with a waist larger than 40" or so I'd guess.
Was the product free of any manufacturer defects? One of the screw holes wasn't threaded right, so I couldn't get the screw in place. However, it wasn't a necessary one - strictly insurance if it's being carried somewhere (never for me).
This is an amazing chair. I have a bad back and MS, so it hard to sit for very long in a chair. This is just the right height for me, I am short.
You can inflate or deflate the ball according to the firmness you want. I find this a good fit for me. It supports me back, while working on my balance. It is light weight and easy to move.
How accurate was the sizing? just right
Please tell us about the quality of the product. excellent
Was the product free of any manufacturer defects? yes
I like this chair as a second chair in my office. It makes you sit up tall. If I were to order another one I would not get the arms or the back. I like the rollers on it. This was my second chair that Overstock sent me because the first one didn't have all the parts. I'm happy with it. It was easy to put together. Overstock was very good about sending me the missing parts and a completely new chair in the box.
How did the image on site compare with the actual product? Good
How accurate was the on site description of the product? very accurate
Please tell us about the quality of the product. Quality is good as can be expected.
The chair's quality is so-so. It was incredibly short. I bought it for my husband who is 6'6" and it literally hits below his knees. It's like the chair needs an extra bar between the bottom and the plate under the ball.