Backache, or back pain, is a common medical problem and is the reason for much absence from work. There are many causes for backache. Some of them are due to serious problems, but most back problems can be prevented by proper use of the back and keeping it in good shape.

The back (or spine) has been described as a brilliant piece of engineering design. It is a shock absorber, a support, a spring, a shield, a communication channel and the centre of an array of levers. With all those different jobs, it is not surprising that sometimes things go wrong .

The back is a column of bones, known as vertebrae, which are held together by muscles and ligaments and are separated by intervertebral discs, which have a cushioning effect. The vertebrae surround the spinal cord, the main route for messages to get to and from the brain. Nerves leave the spinal cord at regular intervals along its length, going to all parts of the body.

There are many small joints in the back which are necessary to allow the vertebrae to move against each other as we perform different activities.

Most backaches are due to problems with the ligaments and joints. More serious problems occur when the nerves are injured, usually by local pressure.

The back is at least risk of injury when it is straight. Anything that forces it to tilt can cause strains to the ligaments, and pain can result.

Being overweight is a good example. A large stomach means that we have to tilt our spines backwards to avoid falling over. Any woman who has been pregnant will agree that this backwards tilt makes life very uncomfortable!

The way we lift, sit at our desks, operate machinery and do hundreds of minor tasks can all affect our backs. Trying to keep the back straight at all times will reduce the risk of backache. This is particularly important with tasks such as gardening and housework, which involve a lot of bending. Whenever possible, bend the knees and keep the back straight when doing things at ground level.

If you have a lot of backache make sure you are not overweight and try to strengthen the back muscles. If the muscles are strong they will take a lot of the strain away from the joints and ligaments of the spine.

Swimming is one of the best exercises for back sufferers: 20 minutes of gentle swimming in a heated pool 3 times a week will do wonders for many of them.