Back curves Dr Rob Hicks Anything that weakens or puts pressure on the spine affects its shape and, consequently, how effectively it works.

In this article

How does the spine work? What causes excessive curvature?

What are the symptoms? What's the treatment?

The spine is the central pillar of the body. It supports the weight of the head and trunk, and provides a protective passage for nerves.

The spine is made up of 33 irregularly shaped bones, or vertebrae

The spine is made up of 33 irregularly shaped bones, or vertebrae. Each vertebra has a hole in the middle through which the spinal cord runs. In between these vertebrae are discs filled with soft material, which act as shock absorbers.

Seen from behind, a normal spine is straight and stretches vertically from the head down to roughly the top of the cleft between the buttocks.

From the side, the spine has two curves: one at the top of the back bending outwards and one in the small of the lower back curving inwards.

Excessive curvature of the upper spine is called kyphosis. Typically, the back appears hunched and more rounded than usual.

Poor posture may contribute to its development over the years, but diseases affecting the spine - such as osteoarthritis or osteoporosis - are responsible. Children can have kyphosis, but the cause is usually unknown.

Excessive inward curving of the lower back is called lordosis. Being overweight is a common cause. Having a large belly leads to imbalance. To compensate for this - and to prevent toppling forwards - a person will lean backwards.

Weak abdominal muscles or poor posture may also be partly responsible. Having kyphosis may even contribute to lordosis developing.

When the spine curves to the side it is called scoliosis. This occurs most often in the upper chest area or lower back and often there's no obvious cause.

It's more common for women to develop scoliosis and it can run in families. Some babies are born with congenital scoliosis. Rarely, diseases causing muscle weakness around the spine may be responsible, such as muscular dystrophy.

If the legs aren't the same length, this will cause the spine to curve.

Kyphosis and lordosis can cause muscular strain and muscle aches.

A person with scoliosis may have an abnormal gait

Scoliosis, if not obvious from birth, tends to develop during childhood and teenage years, and gradually becomes more visible. Bending forwards makes it more obvious. A person with scoliosis may have an abnormal gait, which contributes to back pain that may be experienced intermittently.

It's important not to ignore the emotional effects of scoliosis, particularly because it tends to appear at puberty when many other body changes are also taking place.

In kyphosis and lordosis, physiotherapy can help to strengthen the supporting muscles of the spine and correct poor posture. Where there's an underlying cause, such as osteoporosis, this needs to be treated.

Maintaining an ideal weight is also advisable to avoid further problems.

Treatment of scoliosis also involves physiotherapy to strengthen the supporting muscles of the spine and where a cause is known this must be corrected. Wearing appropriately raised shoes to make the legs of equal length, for example, can help.

When scoliosis is severe or getting worse quickly, it may be necessary for a spinal brace to be worn to prevent further curvature, or to have spinal surgery.

This article was last medically reviewed by Dr Rob Hicks in November 2007