I once had a math professor in school who used to walk down students’ rows, pick up the hand of some unassuming kid doing math problems, and start cracking their knuckles. Slowly, it graduated from that to cracking wrists, arms, and once, even a poor boy’s ear. Surprisingly, nobody objected to this gross invasion of personal space, but I kept hearing jokes about how we’re all going to get arthritis.
And while I’d love to get a crack at revenge by developing an incurable joint disease (and maybe making him pay for it), I’m afraid to say the only repercussions of his actions are my feeling intense annoyance for eternity. For knuckle cracking is not harmful folks, no matter how many family members told you otherwise.
A study of a geriatric population with a history of knuckle cracking, titled “The Consequences of Habitual Knuckle Cracking,” could not prove that a lifelong affinity for cracking knuckles led to any degeneration in the person’s metacarpal phalangeal joints of your digits (aka the ones you probably crack the most). “The chief morbid consequence of knuckle cracking would appear to be its annoying effect on the observer,” the study concluded. Another experiment by a California physician, who habitually cracked knuckles of only one hand over the course of his life, revealed no difference in joint health between both of his hands, according to Harvard Health.
While the loudness that accompanies cracking a knuckle is probably ominous, the underlying mechanism that produces the sound is quite harmless. When fingers are stretched or positioned to crack, the space between finger joints widens. In that space, gas bubbles form, which then immediately either burst, or collapse — thus producing a popping sound. It’s hard to crack the knuckle immediately afterward because the gas bubbles take a while to form again.
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Vigorous knuckle cracking — if you’re really going at it — might result in joint dislocations or tendon injuries, Harvard Health says. One study, published in 1990, that evaluated 74 people who cracked their knuckles habitually? found less hand-grip strength and more instances of hand swelling than those who did not. With such a small source pool, however, the study’s results are far from conclusive.
So, as long as your digits are not swollen or painful, knuckle cracking might be annoying, but definitely nothing to worry about. Get crackin’, I’d say. As long as you do it to your own self, please.
