“CRACKING KNUCKLES WILL CAUSE ARTHRITIS”
Knuckle cracking involves pulling apart the joints by stretching or bending them, which decreases the pressure in the fluid between them. This causes dissolved gases in the fluid to form bubbles, which then burst with a characteristic crack. Legend has it that this causes osteoarthritis, where the cartilage covering the ends of the bones becomes thin and roughens. But this legend isn’t true.
In 1998, Dr Donald L Unger wrote a letter to the editor of Arthritis and Rheumatology. He had been cracking the knuckles of his left hand at least twice a day for 50 years, with his right hand acting as the control. He had compared both hands for evidence of arthritis and found none, but he did confess that his study wasn’t enough to debunk the myth.
However, a larger study later appeared in the Journal of the American Board of Family Medicine. The team quizzed 215 people aged 50–89 about their knuckle-cracking habits and looked at X-rays of their hands. The result? There was no difference between those who cracked and those who didn’t.
Osteoarthritis is caused by wear to the cartilage that covers the joints