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Cedars-Sinai Blog

Ask a Doc: Is Knuckle Cracking Bad?

Cracking knuckles, hands, fingers, popping

"The noise of cracking or popping in our joints is actually nitrogen bubbles bursting in our synovial fluid."


What’s cracking

We asked Dr. Robert Klapper, orthopaedic surgeon and co-director of the Joint Replacement Program, to explain what actually happens when you hear your joints snap, crack, and pop.

"The noise of cracking or popping in our joints is actually nitrogen bubbles bursting in our synovial fluid," says Dr. Klapper.

According to Dr. Klapper, synovial fluid lubricates your joints like motor oil in a car's engine, reducing friction and preserving our cartilage. The nitrogen bubbles within the synovial fluid usually take 20 minutes to re-form in your joints before they can crack again.

Part of the appeal of knuckle cracking could be that 20-minute lull, when gas bubbles are re-forming in the synovial fluid. You might feel looser during that period, as if you’ve relieved pressure from your joints.

But the satisfaction is mostly in your head.

"Feeling good after cracking your knuckles is a psychological experience," says Dr. Klapper.



Were your parents right about arthritis?

If you don’t experience pain while knuckle cracking, then you’re free to indulge yourself.