I was a bit concerned reading the description and the reviews because the chair is recommended for people 5 '6" or taller--and I'm 5' 3", maybe 5' 2.5". In any case, it's perfect! I sit on the top of the "chair" and my feet easily sit flat on the ground. However, it is hard to "bounce" very much while trying to read or type so I'm not about to use the lymph circulating properties as much as I would like.
Metal bar in the front that holds the weight of the ball as it expands when I sit on it pulled through the plastic on both sides. I kept it inflated but it didn't help relieve the pressure. Once the plastic broke the chair is worthless. Disappointing!
I needed a new chair for my desk and I am so happy I bought this one. If you are hesitant, just purchase it- you won't be disappointed. Very easy assembly. I only had to pump up the ball again the second day. I am a graduate student and this chair is perfect for studying while maintaining a healthy posture. I did buy the extenders to make it taller.
This chair was very easy to put together. I did have to make several adjustments to the inflation of the ball to be sure my hips and knees were on the same level, but it was not a problem to do that. I plan on using the chair at my computer desk at home and hope it will help me to strengthen my core muscles which in turn will improve my lower back stability. It does help me sit up straighter and not slouch as much! I've noticed only one slightly, but very minor, thing about the chair and that is it doesn't roll away from the desk real easily as I want to get up (chair is on thicker home carpeting). All in all, I do think this is a great chair.
A couple of people in my office have this chair and I decided to try one as well, and I love it!. It was easy to put together. It's light weight so it rolls from my desk to the table easily. I do believe it is helping my posture and reducing stress on my lower back.