What Is Scoliosis? Scoliosis is a condition where the spine curves or rotates sideways  when viewed from behind. Normally, when looking at someone from the front or back, the spine should appear relatively straight. When viewed from the side, however, the spine naturally forms gentle curves that help with balance and shock absorption. With scoliosis, the spine develops an abnormal sideways curve , which may form a “C” shape or an “S” shape . In some cases, the vertebrae also