This new invention combines the exercise ball and a seat to form a chair. The manufacturer Isokinetics Inc say that this chair promotes what they call “active sitting” which is designed to exercise muscles that you wouldn’t normally when sitting. Due to the shape of the ball, the user has to constantly move, even without knowing in order to balance themselves.
When looking at the evidence for this, it is extremely hard to tell whether the evidence put forward is conclusive. There have been tests carried out by the Canadian Chiropractic Association that may suggest that the ball actually helped people with severe back pain. To give one case was a 55 year old male who whilst working in a warehouse for 25 years had developed recurring back due to his posture and having to spend a lot of time bent over at work. When using the ball, he would sit on it for two minutes and found that it would irritate his back making it unbearable to sit on the ball, but his persistence paid off and after eight weeks he found he could sit on the ball for 20 minutes a day and there was a significant reduction in his back pain which he reported was all over his back from the upper, mid to the lower back. After using the ball it was documented that his sharp back pain and leg pain had completely gone, and the pain the he did have was more of an ache.
On the other hand, the New York Times have stated that they believe that there is no conclusive evidence that the ball works to reduce lower back pain and this is backed up by Jeremy Vigneault, a physical therapist at the Nayden Rehabilitation Clinic at the University of Connecticut, who has been quoted in saying “there is really nothing overly good nor bad per say about the exercise ball chair”. Others such as the Ergonomics Today say they are against the ball for safety reasons, although it is worth noting that this is mainly due to people falling off as the ball rolls away, a problem that seems to be overcome with the chair.
In conclusion, you will have to make your own mind up about the exercise ball chair. However, I am sure that within time, we will have a better understanding about this new ergonomic chair and be able to make a better judgement.