The chair back consists of a short shaft and a chair ring that can move up and down. When a person sits in a fitness chair, his spine will stick to the chair post. At this time, the chair can't move, but they need to grasp the chair ring with both hands and move up and down constantly, so that the chair ring drives the fulcrum on the chair column to roll up and down and cling to the human spine, thus achieving the purpose of exercising both arms and massaging the spine. Therefore, as long as you sit comfortably, you can exercise your whole body muscles, get rid of all excess fat and strengthen your lower back and spine.