Is It Bad to Crack Your Knuckles?

“It is bad to crack your knuckles?” If you’re a knuckle-cracker, someone’s probably told you that it causes arthritis. One of our patrons was curious as to whether or not that was actually true.

We have a new book in the library, Is That a Fact? by Dr. Joe Schwarcz, which investigates popular health rumors like that and sees whether or not they can be backed up by scientific evidence. Unfortunately, we couldn’t find anything about knuckle-cracking in it. However, it turns out it’s a popular enough question that we could find the answer online. BBC.com, WashingtonPost.com, and ScientificAmerican.com, among others, have all tackled the question.

Cracking knuckles won’t actually lead to arthritis. Occasionally, people have been known to injure their thumbs or tear the ligaments in their fingers by cracking their knuckles too zealously, but there’s no evidence that it’ll cause harm over time.

So what’s actually making the snapping sound when you crack your joints? Your joints are surrounded by a capsule filled with liquid called synovial fluid. When you crack your knuckles, you’re popping the bubbles in the fluid. That’s why it takes a while after cracking your joints to be able to crack them again – the bubbles need time to reform.

Age, family history, and strain on your hands, whether from injury or through work, are the most common factors causing arthritis. For anyone interested in learning more, The Arthritis Sourcebook edited by Amy L. Sutton, is available through CLEVNET.