The Facts on Knuckle Cracking
By Paul Rothbart
Cracking the knuckles is a fairly common habit. Studies have shown that as much as 54 percent of the population does it. Many consider it a bad habit and parents often tell their children that knuckle cracking can cause arthritis, swelling of the joint, or weakening of the grip. Then there are those who feel it loosens up the fingers and hands, preparing them for tasks requiring dexterity like playing the piano. But what are the facts? Why do people crack their knuckles and is it good or bad for you? Here is what medical science has to say.
The Reasons People Do It
Cracking the knuckles is a habit, similar to nail biting. There are people who do it when stressed or nervous. Activity in the hands can take focus off the anxiety. Some people like the sound of the pop they get from each knuckle. For some, it feels like a loosening of the joint, relaxing the hands. It can also become a habit, difficult to break. It becomes ingrained and some people will crack their knuckles multiple times a day.
Why Do They Pop
It's called cracking because of the sound. A sharp crack or pop emanates from the knuckle. A 2015 study used an MRI to monitor knuckles while they were cracked. It showed that pulling the joint apart created a negative pressure that caused a temporary cavity to form. The researchers concluded that this cavity produced the sound.
Further research done in 2018 discovered that it was the partial collapse of the cavity that caused the sound. The study also showed that it takes about 20 minutes for the cavity to fully collapse, which is why it takes about that long before the knuckles can be cracked again.
Is It Harmful
As to the question or whether or not cracking the knuckles damages them, the short answer is that it does not. The Swiss Medical Journal referenced numerous studies and concluded that there is no evidence whatsoever that knuckling cracking causes arthritis, finger swelling, or any other joint damage. In fact, a doctor performed a 50-year experiment on himself, where he cracked the knuckles on his left hand multiple times a day but never the right. At the conclusion of the experiment he did not experience arthritis in either hand and the knuckles on both hands were identical and functioned normally. There is also no evidence that cracking the knuckles loosens the joints. It doesn't harm, but it doesn't provide any benefits either.
Cracking the knuckles is a habit for many people and just as many find it annoying. Perhaps that's where the stories of arthritis and other damage come from. But love it or hate it, it won't hurt the knuckles or fingers or loosen them up. Just one of those benign things that can become habitual.
To learn more about your health, wellness and fitness, see your local chiropractor at The Joint Chiropractic in Mt. Prospect, Ill.