When viewed from the front or back, the normal spine is in a straight line, with each vertebra sitting directly on top of the other. Curvature to one side or the other indicates a condition called scoliosis.
When viewed from the side, the normal spine has three gradual curves:
- The neck has a lordotic curve, meaning that it curves inward.
- The thoracic spine has a kyphotic curve, meaning it curves outward.
- The lumbar spine also has a lordotic curve.
These curves help the spine to support the load of the head and upper body, and maintain balance in the upright position. Excessive curvature, however, may result in spinal imbalance.