(Dec 5) THE CLAIM: Growing pains are caused by growth spurts

THE FACTS: The aches and pains strike in the middle of the night for no apparent reason. For decades, doctors have dismissed them as normal signs of growing in small children, and have said the pain is harmless.

Most textbooks attribute these 'growing pains' to the stretching of leg muscles, caused by the rapid growth of bones.

But despite widespread acceptance of this claim, there is virtually no evidence to show that it's true. Most studies have found instead that the pains - which can affect nearly half of all children - result from brittle bones and physical activity, in particular, from running, climbing and jumping during the day.

In 2005, for example, a study in The Journal Of Rheumatology recruited 39 children with symptoms of growing pains and compared them with a control group.

After ultrasound tests, the researchers found that the children in the pain group had decreased 'bone speed of sound' - a measure of bone strength and breakability - suggesting that they suffered instead from 'a local overuse syndrome'.

Other studies have had similar results, and some have also found that restless leg syndrome and other conditions are sometimes confused with growing pains. Researchers say that rather than dismiss the pains, parents can alert their children's paediatricians or try massages or the use of a pain reliever.

THE BOTTOM LINE: Research suggests that growth spurts do not cause pain.