A normal spine, when viewed from behind, appears straight. However, a spine affected by scoliosis shows a side-to-side curvature, with the spine looking like an "S" or "C." The back bones (vertebrae) may also be rotated. This makes it look like the person is leaning to one side. Scoliosis is defined as a curvature of the spine measuring 10° or greater.
Scoliosis is not due to poor posture.
Spinal curvature from scoliosis may occur on the right, left or both sides of the spine. Both the thoracic (mid) and lumbar (lower) spine may be affected by scoliosis.