Bests & Worsts Reviews from Amazon

I purchased this chair because I have lower back pain. I've had it now for about 6 months and find that at the end of the day my back feels much better. I don't use the ball for working out, I only use it as an office chair. It definitely takes a little while to get used to it. The first few days, my back was sore and I almost went back to my old chair. It was sore, but it didn't hurt. After about a week, I stopped noticing my back being sore. I'm pretty sure it is because my back had to build up the muscles to support my body. Which is exactly what I was hoping it would do. The chair doesn't allow you to lean on the back of a normal office type chair, therefore forcing you to use your back muscles. It doesn't force you to have perfect posture, but without the ability to lean on a backrest, it reminds me throughout the day to sit up right. After a couple of months, I do it naturally now. I realized how much the chair has helped with my back pain last week. One of my co-workers asked to try the chair out for a couple of days. My back hurt at the end of the day significantly more than it has in months. Pretty conclusive proof that this works for me. Be warned, you'll get a lot of funny looks when people first see it. Even the UPS guy laughed at me while delivering it. I don't care! It makes me feel better. The bottom line: Be prepared for a week or two of time to get used to it and build up the back muscles. I think afterward you'll thank yourself. ***UPDATE*** Almost 2 years now since I bought this chair and I still sit on it every day. Have not had lower back pain at the end of the day since a few weeks after I bought it. Still 5 stars for me!