Cracking knuckles seems like a such a small thing. There are many misconceptions about cracking knuckles, one of the most famous being that if you do so you will develop arthritis. It’s something most people do, however it is more of a mystery than you might think. Scientists disagree on how exactly cracking knuckles works. Some scientists theorize that it is caused by a joint or tendon resettling. Another theory is that it is a result of carbon dioxide either popping or forming in synovial fluid (the fluid that lubricates a person’s joints). However, Dr. Robert Boutin a professor of radiology at University of California Davis developed a different theory.
Boutin divided the people participating in the study into two groups. The first group was thirty men and women who cracked their knuckles. Boutin estimated the amount of times the participants had cracked their knuckles and recruited 10 non-knuckle crackers. Next, the subjects cracked their knuckles at the metacarpopphalangeal joint, while the joint was scanned by an ultra sound. Out of 400 trials, only 62 produced an audible crack. In all of the cases were an audible crack was produced, researches observed a flash. The flash seems to support the bubble theory. Boutin claims that he remain uncertain about whether or the crack comes from a bubble popping or forming, and says that more research is needed. However, he did state that the crack proceeded the flash, supporting the idea that the crack comes form the bubble forming.
The study seems to have been well conducted, however the sample size is a little small. The researchers did end up submitting the sonograms to radiologists who were not involved in the study, and thus did not know which knuckles cracked. Nevertheless, they predicted which knuckes cracked with 94% accuracy.
http://time.com/4130607/knuckle-cracking-bubble/
http://time.com/3529225/cracking-knuckles-arthritis/
I am a chronic knuckle/finger cracker. I started young and have found I can tell when my fingers haven’t been cracked in a while. And while we were told growing up that it wasn’t good for you, that is in fact false. So much so that Dr. Donald Unger won a 2009 Nobel Prize for proving that cracking your knuckles does not cause arthritis. The doctor went sixty years cracking only the knuckles in his left hand, while never once cracking those in his right. What he found was there were no significant differences in the likelihood of getting arthritis or damage to your hands.
Take that, Ms Tisse! (my third grade teacher)
http://tech.mit.edu/V129/N41/ignobels.html
I have heard that cracking your knuckles is not as bad as the rumors that have gone around for years, but I was never really sure about cracking my neck. Apparently it is similar to cracking your fingers and most joints because it caused by the release of gas from the joint. There are fluids and gassed in our joints, and with certain movements or pressure applied in a certain way, the joint can release gas causing the popping sound. A Stroke is possible from cracking your neck but it is extremely rare to come by, and usually involves other factors than just cracking your neck.
http://www.huffingtonpost.com/2012/10/03/neck-cracking-dangerous-spinal-manipulation_n_1929690.html
I feel like this is a post that a lot of people can relate to. Myself included. I’ve been cracking my knuckles everyday for years now. As anecdotal evidence, I haven’t experienced any negative side effects. In fact, I’ve read that cracking your knuckles can actually release small amounts of dopamine. Maybe that’s why knuckle crackers never seem to take a day off..
I can’t tell you how glad I am that you posted this, because I too have heard a bunch of theories about cracking, and it’s settling to hear that it is believed to be the air bubble idea. I have heard also that its not just joints resettling, but instead the sound of cartilage sliding out and the eventual bone on bone contact from a lifetime of cracking is what creates the arthritis. But of course these were just anecdotal evidence as opposed to a legitimate experiment.