Why might crossing your arms reduce hand pain?

THAT'S THE WHY:What do you do if you hit your hand? You probably rub or kiss the sore bit in the hope it will feel better.

But a new study suggests that crossing one hand over the other, so your forearms form an “X”, might also dull the pain of injury.

In a paper just published in the journal Pain, an international group of researchers looked at how eight healthy volunteers perceived laser-induced pinpricks of pain on their hands.

They self-rated the pain when the hand was on its usual side of the body, and when it was crossed over to the other side. To add to the fun, the experiment also used EEG to track their brain responses.

And the findings suggest that the pain was perceived as being less intense if the hand was crossed over.

So why might putting your hand across the midline of your body have this effect?

“In everyday life you mostly use your left hand to touch things on the left side of the world, and your right hand for the right side of the world – for example when picking up a glass of water on your right side you generally use your right hand,” explains researcher Dr Giandomenico Iannetti from University College London.

“This means that the areas of the brain that contain the map of the right body and the map of right external space are usually activated together, leading to highly effective processing of sensory stimuli.

“When you cross your arms these maps are not activated together anymore, leading to less effective brain processing of sensory stimuli, including pain, being perceived as weaker . . . Perhaps when we get hurt, we should not only ‘rub it better’ but also cross our arms.”