Whether you crack your knuckles by pulling on each finger, making a fist or bending your fingers backwards while others around you cringe, somebody probably has been telling you that cracking your joints leads to arthritis.
In a new video (below), Vox reveals what causes the cringe-inducing sound, and whether cracking your joints actually damages your hands.
The video explains that the popping sound you hear when you crack your knuckles is just a release of gas bubbles from synovial fluid, a “lubricant-like substance” found around the joints. In contrast, the “crack” you hear from your knees when you stand up too fast is tendon moving over muscle and bone.
As for the claim that knuckle-cracking can cause arthritis, Vox cites a study conducted by one researcher, Donald Unger, who cracked his knuckles on just one hand for 60 years. He concluded that neither hand was more arthritic than the other.
While cracking your knuckles may not lead to arthritis, one 1990 study of 300 people did find that habitual knuckle-crackers were more likely to have hand-swelling and decreased grip strength. However, there has not been any follow-up research on that study.
Check out the video: