There are essentially four varieties of ball chair. There is the original ball chair designed by Eero Aarnio in 1963, the suspended ball chair, usually referred to as a bubble chair by the same designer; the exercise ball in a frame, which is ostensibly for the gym or home use and a refined version of the gym exercise ball for office use.
The original ball chair was designed by Eero Aarnio, because he had just gone freelance and so was working from home. He did not want to close himself away from his family, but he also desired some peace and quiet in order to work. His concept was the ball chair. It is essentially a ball on a revolving pedestal with a segment cut away. The inside of the ball is sumptuously upholstered in fabric or leather.