The normal spine has an S-shaped curve when viewed from the side. This shape allows for an even distribution of weight and flexibility of movement. The spine curves in the following ways:
- The cervical spine curves slightly inward, sometimes described as a backward C-shape or lordotic curve
- The thoracic spine curves outward, forming a regular C-shape with the opening at the front - or a kyphotic curve
- The lumbar spine curves inward and, like the cervical spine, has a lordotic or backward C-shape
The curves of the spine can be exaggerated in any plane, leading to pain, deformity and neurologic dysfunction. Some abnormal curves are asymptomatic while other require treatment.
Some excessive and abnormal curves are amenable to surgical treatment. Excessive kyphosis or increased angulation forward can be due to trauma or other causes. Scoliosis or a lateral curvature of the spine viewed from the back may be corrected with surgery. There are many types of kyphosis and scoliosis that only need careful observation.