What’s really going on when you crack your knuckles or knees

SOME people love to crack their knuckles, much to the chagrin of others who find it disgusting.

Some can hear their knees pop when they squat. What exactly is that about?

“We don’t know,” says Caroline Werkmeister, an orthopaedist who works at the university hospital in the Eppendorf, Hamburg.

Scientists have tried hard to establish why some people have noisier joints than others, but there has been no conclusive research on the matter.

The only thing we know for sure is that it’s something to do with nitrogen and carbon dioxide bubbles building up between the joints, and that the lower the atmospheric pressure, the more likely it is to happen.

The cracking sound is thought to be produced when the gas abruptly changes back to liquid in response to a reduction in pressure.

“However, there are simply no major studies on the issue,” Werkmeister warns.

So what should we do about it? Crack away, Werkmeister says – the lack of evidence on the matter suggests that it can’t be a huge problem.

“If people who can crack their joints were more likely to develop problems with those joints, we would presumably have noticed by now,” she says.

However, you should see a doctor if you experience any pain when cracking your joints. – Text by dpa