ng> That was a new ball chair design. Many people use a stability ball as a chair; however, it is not a perfect option without a base because it has a tendency to roll away when you get up and if you use a ball that is the correct size for your body it can press against your calves making it uncomfortable. Also, a regular stability ball without a base may not be the correct height for your desk. The ball chair takes the benefits of the stability ball and puts them into a chair. It has adjustable legs so it can use a smaller ball that does not take up so much room or interfere with your natural leg position. This adjustability also makes it suitable for anyone from five feet to six foot five! Sitting all day in a regular chair can cause muscle weakness and poor posture, which increases your risk of developing back pain. The ball chair demands good posture which can release muscle tension and decrease back pain. It also improves your balance and strengthens your torso, the distribution company calls it “active sitting” because you can’t totally relax. It helps you burn more calories at work and makes it easier to get up and down because your postural muscles are always engaged. It is also a good option for teenagers.