Is Cracking Your Knuckles Bad For You?
Researchers looked at several studies that compare rates of hand arthritis among daily knuckle-crackers compared to people who didn't crack their knuckles. Results showed that people with this regular habit were more likely to have swollen hands and reduced grip strength — but arthritis was not an epidemic.
Additionally, there are at least two published reports of people suffering injuries while people trying to crack their knuckles.
For many years, scientists were trying to understand why our joints make the relieving popping sound.
In an April 2015 study, researchers from the University of Alberta in Edmonton used an MRI to see what was going on in the cracking knuckle joints. The scan revealed that the crack occurred when the joints momentarily separated and was caused by the collapse of air bubbles that form in the synovial fluid, which lubricates our joints.In December, researchers from the University of California, Davis attempted to confirm this finding using ultrasound machines instead of MRIs to record cracking behavior.
For the study, a sonographer recorded the knuckle cracking behavior of 40 men and women, 30 of whom had reported a history of habitual knuckle cracking. Two radiologists then interpreted the ultrasound images in order to best find evidence for the source of the audible cracks."What we saw was a bright flash on ultrasound, like a firework exploding in the joint," said Dr. Robert D. Boutin, professor of radiology at University of California, Davis (UC Davis) Health System and a researcher involved in the study in a recent statement."It was quite an unexpected finding."