This patented balance ball and ergonomic chair provide healthy, proactive sitting, while improving posture, reducing fatigue & building your core strength. We spend hours every day sitting on chairs, whether we're at the office or sitting at home. However, the human body wasn't designed for sitting in these chairs. Many ergonomic chairs claim to hold the body upright, but only for a short period of time. Shortly after, the posture muscles tire, causing the body to slump and slouch as the spine twists out of alignment. Eventually, the muscles weaken, ultimately leading to back pain and potential back injury. The Fitness Ball Chair helps in relieving stress and strain on the spine and aids in eliminating repetitive motion injuries. It also helps reduce, neck, back and shoulder pain.