Why rubbing a bump or scrape makes it feel better?

LONDON - Does rubbing a bump or scrape make it feel better? Scientists found that people experience much less pain when they gently rub a sore part of the body.

The finding helps explain why most of us instinctively clutch an arm or leg when it is injured, but are reluctant to let anyone else touch it.

British scientists believe that touching an injury helps to reset the brain’s internal ‘map’ of the body - that seems to play a key role in pain perception, reports the Daily Mail.

Scientists studied the soothing power of touch using a well-tested lab experiment that inflicts pain on volunteers without causing physical damage, according to the journal Current Biology.

Study author Professor Patrick Haggard of the University College London said: “The index and ring fingers are placed in warm water and the middle finger in cold water.”

“This generates a paradoxical feeling that the middle finger is painfully hot.” In the experiment, the volunteers were asked to place both hands into the water until they felt pain.

Once their fingers were lifted out of the water, they were asked to record how much pain they were experiencing on a scale.

When they were allowed to bring their two hands together - so each sore finger was touching its opposite number - the painful heat experienced in the middle finger dropped by 64 percent.

But on occasions when they kept their hands apart, the pain levels stayed the same. Touching the hand of somebody else made no difference to pain levels. And the pain levels only dropped when all the volunteer’s fingers were touching.

Marjolein Kammers of University College London, said the study shed light on the origins of pain in the brain.