Curve patterns
There are three parts to the spine: the cervical spine (neck), the thoracic spine (mid back), and the lumbar spine (low back). The spine should look relatively straight when viewed from the front or back. Scoliosis is when the spine curves sideways, usually into the shape of an S or a C. An S-shaped curve is also called a double curve. A C-shaped curve is also called a single curve.
There are five main curve patterns:
Type I curve
An S-shaped curve that involves the thoracic (mid-back) and lumbar (low back) spine. There are two curves. The
lumbar curve (low back) is bigger than the thoracic curve (mid-back).
Type II curve
An S-shaped curve that involves the thoracic and lumbar spine. There are two curves. The thoracic curve is bigger than the lumbar curve.
Type III curve
A shorter, C-shaped curve that involves the thoracic spine.
Type IV curve
A longer, C-shaped curve that involves the thoracic and lumbar spine.
Type V curve
An S-shaped curve that has two curves in the thoracic spine. The mid-thoracic curve is bigger than the upper thoracic curve.
Physical changes to the body
When a curve in the spine develops, there are also changes to the rib cage, shoulders, and hips. As the curve(s) in the spine start to increase in size, the spine begins to twist. The ribs, which are attached to the spine, also twist. The ribs become more curved or more pronounced on one side of the body. This is called a rib prominence.
A rib prominence can be clearly seen when the teen with scoliosis bends over to touch their toes. The rib prominence is much higher on the side where the spine is curved. In larger curves, the rib cage may twist so much that the chest may push forward on one side.
Some females may also notice that one breast is larger than the other. The shoulders are also affected. Usually one shoulder is higher than the other. Sometimes, in more severe curves, the shoulder is also pushed forward. Depending on the location of the curve(s), one hip may be higher than the other. Alternately, one hip may appear to be pushed forward on one side.