This Is What Actually Happens Every Time You Crack Your Knuckles

by Sean Levinson

Cracking your knuckles is a great way to loosen up your fingers when they feel stiff or tense.

This triggers a release similar to a good stretch, and now there's an explanation as to what produces the mysterious popping noise that comes with it.

There's an area in your joints filled with a liquid called synovial fluid.

This substance acts as a lubricant whenever the joints are used, reducing friction between bones and cartilage.

Popping a joint stretches out that space, creating a pressure that sucks in synovial fluid.

The fluid contains gases like oxygen, nitrogen and carbon dioxide, and the vacuum-like pressure turns them into bubbles.

The pop that accompanies cracking a knuckle is, in fact, the popping of these bubbles.

Ever try to consecutively crack the same knuckle?

It doesn't work because it takes approximately 20 minutes for the synovial fluid to become filled with gases again.

But anyone who regularly cracks his or her knuckles knows it gets easier over time, and that's because the more you crack a knuckle, the looser that joint gets.

And unless it starts to hurt, crack all you want because it doesn't seem to mean you're an early candidate for arthritis.

Dr. Donald Unger tried to prove this by cracking his knuckles for 60 years -- but only those in his left hand, according to Vox.

He didn't crack his right knuckles once during this period, so he could compare the two hands.

After all those years, neither hand had developed arthritis.

Dr. Unger's findings were supported in a 2010 study that found out of 215 people, those who didn't crack their knuckles surprisingly tended to be a little more likely to become arthritic.

The popping you might hear when you move a formerly immobilized body part isn't anything to worry about, either.

This is just the quick snap of a tendon during the movement of a joint.

Joint popping is natural, pleasurable and hasn't been proven to result in any unhealthy conditions.

So rejoice: There is at least one guilty pleasure you don't have to actually feel guilty about.

Citations: Whats actually happening when you crack your knuckles (Vox)