Can Cracking Your Knuckles Actually Be Good For You? A New Study May Surprise You

If you love to crack your knuckles but avoid it because you always thought it would eventually cause arthritis, you may want to think again. A recent study claims that cracking your knuckles may actually be good for you. In fact, this may be exercise for your fingers.

Robert D. Boutin, M.D., professor of radiology at University of California, Davis (UC Davis) Health System, said that the team began the study because “It’s extremely common for joints to crack, pop and snap.” They were curious. They wanted to find out if the knuckle cracking sound was the result of a bubble being created in the joint or if a bubble was popping in the joint.

“We were interested in pursuing this study because there’s a raging debate about whether the knuckle-cracking sound results from a bubble popping in the joint or from a bubble being created in the joint.”

The study by the RSNA, the Radiological Society of North America, included participants from all sides of the knuckle cracking spectrum. The study included participants that never cracked their knuckles all the way to those who did it up to 20 times per day, for as many as 40 years in a row. The Orthopedists who conducted the study knew nothing about each participant, whether they cracked or not. As they were not aware who was actually was a knuckle cracker, they treated each participant identically. They checked for range of motion, grip strength, laxity of each MPJ both before and after an ultrasound.

As each participant tried to crack their knuckles, the Orthopedists used a small transducer. This sonographer records video images of 400 MPJs. In addition, the sonographer captured static images of each MPJ. This was done before they tried cracking their knuckles and then after they successfully cracked their knuckles. This way, the Orthopedists could compare between the two.

Searching for a visual image through the ultrasound, the radiologists looked for proof of any physical change after the participant’s knuckles were cracked. This proof occurred in 62 out of the 400 sonographs made. From the study, Dr. Boutin said that this is when they saw something quite unexpected: they saw a bright flash when the knuckle was cracked.

“What we saw was a bright flash on ultrasound, like a firework exploding in the joint. It was quite an unexpected finding.”

Using the flashes on the ultrasound images, the radiologists were able to identify the joints with audible cracks with at least 94 percent specificity.

“There have been several theories over the years and a fair amount of controversy about what’s happening in the joint when it cracks. We’re confident that the cracking sound and bright flash on ultrasound are related to the dynamic changes in pressure associated with a gas bubble in the joint.”

Dr. Boutin advised that more research is needed to determine what comes first: the flash of light or the cracking sound. With this small test group, the researchers did not find any sort of disability, pain or even swelling by the knuckle-cracking group. In addition, there was no difference in grip strength from the variety of participants, some who were knuckle crackers and others that didn’t crack their knuckles.

Despite their discovery that there was not a disability discovered after examining knuckle cracking participants, the group decided that additional research needs to be conducted.

“We found that there was no immediate disability in the knuckle crackers in our study, although further research will need to be done to assess any long-term hazard – or benefit – of knuckle cracking.”

Do you crack your knuckles? Do your fingers feel like you just did yoga after cracking your fingers? Or do you consider the sound of knuckle cracking to sound like a nail on a chalkboard?

[Photo by Bruno Vincent/Getty Images]