Snap, Crackle, Pop: Researchers Say It's Safe to Crack Your Knuckles

— -- If you enjoy a satisfying "pop" after cracking your knuckles, you can breathe a sigh of relief: medical experts now say it's probably harmless to give your knuckles a satisfying snap, crackle or pop when needed.

A new study, presented this week at the Radiological Society of North America, found that you can crack your knuckles without worrying about negative side effects. Researchers looked at 40 subjects -- some whom cracked their knuckles often and others who never did. They looked at the subjects' range of motion, ability to flex their fingers, grip strength, in addition to other tests. They also used an MRI to see if there were changes under the skin. But the researchers found there was no significant difference between those who popped their knuckles and those who didn't.

"What we saw was a bright flash on ultrasound, like a firework exploding in the joint," Dr. Robert D. Boutin, a professor of radiology at UC Davis and the study's lead author, said in a statement on Tuesday. "It was quite an unexpected finding."

Dr. Kevin Malone, chief of hand surgery at University Hospital Case Medical Center, said that it is still slightly mysterious about why the sound occurs, but that it appears to be safe to crack the knuckles.

"There’s no evidence to say there’s any problem with doing it," said Malone, who was not involved with the study. "There’s no correlation with arthritis that’s been identified or any kind of joint problem associated with it."

Malone explained that the current theory is that gasses in the joints build up and create pressure and a well-timed "pop" can release that pressure quickly.

"It’s a benign thing, it grosses some people out," said Malone, who admits to cracking his knuckles on occasion.

Malone said there are other occasions where people feel a joint "pop or catch" unexpectedly and that in those cases it could be due to arthritis or other conditions.