To Crack or Not to Crack

Is cracking knuckles bad for you?

It will make your knuckles bigger. It will cause arthritis. It will hurt your joints. Will it? A story in the Washington Post brought the age-old argument about whether or not cracking knuckles is bad for you back to life.

First of all, what the heck makes those knuckles crack?

According to the Johns Hopkins Arthritis Center, it's all about the gas. What? Seriously, here's the deal:

Joints (knuckles) are covered by a capsule (the joint capsule or synovial capsule). Within the space of this capsule the synovial fluid is contained which acts as a lubricant and also contains nutrients for the adjacent bone surfaces. A variety of gases are continuously dissolved in this fluid. When one cracks a knuckle, the stretching of the capsule lowers the pressure inside the joint and creates a vacuum which is filled by the gas previously dissolved in the synovial fluid. This creates a “bubble” which then bursts producing the characteristic “popping” or “cracking” sound.

That explains why knuckles can't be cracked again right away after an initial cracking. The gases are re-dissolved in the fluid.

Next question: Does knuckle-cracking really cause arthritis, or is that just some sort of made-up diagnosis by parents who can't stand the sound of their kids' knuckle joints popping at the dinner table?

Washington pediatrician Howard Bennett told the Post that no, knuckle-cracking can't cause arthritis, but overzealous cracking can injure the ligaments that support the joints.

The Johns Hopkins Arthritis Center agrees, saying there is no evidence that is causes damage or arthritis in the joints. But the Center says one study found that after many years of habitual cracking, the guilty parties may have reduced grip strength compared to their noncracking counterparts.

So it's not particularly bad for you, but some find it irritating and distracting, like nails on a chalkboard.

Are you guilty of cracking? Find out how you can stop here. And check out a great example of why you should stop below.

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