Knuckle Cracking Study Proves With MRI What Causes The Popping Sound, But Is It Healthy?

A knuckle cracking study proves what that nasty popping sound comes from, and it is all thanks to the researchers from the Peter S. Allen MR Research Centre, University of Alberta, Edmonton, Canada. But would they go out of their way in order to do this knuckle popping study?

In a related report by the Inquisitr, a study on marijuana extracts proved it was effective at reducing the frequency of epileptic seizures without having the "high" associated with the psychoactive drug.

There has always been plenty of disagreement when it comes to knuckle popping. For example, a comedian once asked the audience to pop their knuckles all at the exact same time in order to create this enormous meaty sound that would send vegans out the door while shrieking in terror. Needless to say, some in the crowd did not enjoy the experience, which was all part of the joke.

Researchers do recognize the humor in their knuckle cracking study since they have dubbed it as the "pull my finger study." Although phrase as a joke, they do recognize that every single human on this planet might be interested in their results.

"It's something that every culture, every society is interested in," said Greg Kawchuk, lead author of the paper published in PLOD One. "We all do it. People love it or are repulsed by it. I quite like the sound, but that's my inner nerd talking."

It turns out this is not the first knuckle popping study. Back in 1947, researchers suggest the knuckle cracking sound was generated from the formation of a gas cavity inside the joint. Fast forward to 1971, and a different set of researchers claimed the collapse of a bubble inside the joint triggered the pop sound. Due to this relatively large disagreement on the cause, the team felt there was a need for a definitive knuckle cracking study, which used MRI technology to finally discover who was correct.

"Rapid imaging with MRI was ideal for these studies because it allowed clear visualization of the bones and fluids surrounding them, and critically, the formation of the air cavity," said professor Richard Thompson of the University of Alberta biomedical engineering, according to the Vancouver Sun. "I personally do not like the cracking sound at all, I think primarily because I always imagined there was damage being done."

Chiropractor Jerome Fryer was the guinea pig for this experiment, and he is now known as the "Wayne Gretzky of knuckle-cracking." They inserted his fingers into a tube that acted like a Chinese finger trap, which pulled until his joint popped.


"As we increased the pull, suddenly you reach the point where you overcome that surface tension and the two joint surfaces suddenly fly apart," said Kawchuk. "In that moment, we saw the creation of an air cavity that happens at the same time the sound is produced."

Although they could not determine what is actually inside the bubble released by surrounding tissues, they are now certain the 1947 knuckle cracking study was correct. The researchers also disagree with your mother, suggesting that cracking your knuckles does no harm.

"Why do the same joints crack in some people and not others?" Kawchuk asked, according to Reuters. "Although speculative, we wonder if being able to crack ones joints is a sign that the joint is actually healthy and that the inability to do so could be a sign of joint problems to come."

[Image via PSU]