Sitting on a Sitfit optimizes one's posture, while supporting the back muscles. Sitting, especially sitting incorrectly with a hunchback, creates an extremely high amount of stress for the spine, intervertebral disks, joints, and ligaments. The pressure load on the spinal disks is five times less in upright standing than it is during sitting. Sitting on a Sitfit or a swiss ball (another of our products) challenges and supports the spinal muscles while enhancing posture. Swiss balls are not always convenient for all persons or situations, thus the Sissel Sitfit was created to give the same benefits as the balls without the inconvenience of a rolling ball. Each Sissel Sitfit comes complete with an exercise booklet detailing 10 dynamic exercises to strengthen back, limb, and abdominal muscles. The exercises detail the correct way to stretch and flex the spine, bend the spine and pelvis to the side, rotate the pelvis, strengthen the torso, strengthen the abs and back muscles, improve the shoulder girdle and arm muscles, strengthen abs, back, and leg muscles, coordinate and strengthen the muscles of the leg and the feet. The uses of the Sitfit are many, but none have proved more gratifying to the inventors than the ever growing use of their product by children in our nations schools who have over or hyperactive nervous systems.