Should You Crack Your Knuckles?

Some people crack their knuckles to relieve tension. Others crack them out of habit. Whatever your reason, could forcing that satisfying pop make your knuckles larger or lead to arthritis in your fingers?

Primary care sports medicine specialist Wesley Baker, DO, shares what’s actually happening when you pop your knuckles, and whether that momentary satisfaction comes with long-term consequences.

Is it bad to crack your knuckles?

Popping your knuckles from time to time isn’t necessarily bad, as long as you’re careful about the amount of pressure you’re putting on your joints.

An older study suggested that cracking your knuckles could lead to a weaker handgrip and increased swelling in your hands. But a more recent study from 2017 found that wasn’t the case. And a separate study from the same year further clarified that cracking your knuckles has no damaging effects on grip strength, swelling or range of motion.

“Research tells us there’s no definitive reason to believe that cracking your knuckles can lead to negative consequences,” says Dr. Baker. “As long as you’re not feeling pain or having swelling in your fingers, it’s probably OK.”

What happens when you crack your knuckles?

There are two possible causes for that loud popping noise when you crack your knuckles. Both involve gas in the synovial fluid that lubricates your finger joints.

Researchers have long believed that the sound (called crepitus) happens because pressure changes in your joints as they’re pulled and stretched apart. As a result, the gas inside that protective joint fluid bubbles and bursts, causing that popping sound.

But a 2015 study found that the popping sound might actually be from the formation of a gas-filled cavity rather than from bubbles popping.

“Think of it like opening a vacuum-sealed container or uncorking a wine bottle,” Dr. Baker illustrates. “The sudden change in pressure causes that popping sound.”

Will cracking your knuckles lead to arthritis?

No, popping your knuckles won’t cause arthritis to develop in your fingers.

Inflammation causes rheumatoid arthritis. Natural wear and tear of your bones over time causes osteoarthritis. And as knuckle-popping hasn’t been found to cause any real damage when done carefully (more on that in a moment), you can rule it out as a risk factor for arthritis. And several studies have failed to show an association between knuckle cracking and arthritis.

Possible risks for popping your knuckles

The act of cracking your knuckles may not pose any significant risk, but there’s a “right” and “wrong” way to pop them.

For instance, if you push too hard or pull them in the wrong direction, you could dislocate a knuckle or injure a ligament.

Instead, if you feel the need to crack your knuckles, be careful not to pull or press with too much force, and be mindful of the direction your knuckles are moving.

“When you’re cracking your knuckles, don’t overextend your fingers or put too much pressure on the bone because that could lead to injury,” stresses Dr. Baker.

You’ll know quickly if you’ve made a mistake because it’ll hurt, and cracking your knuckles shouldn’t cause pain.

If you notice swelling — or if your fingers look crooked — Dr. Baker advises seeing a healthcare provider.

Knuckle down

If you feel the need to release some tension, carefully cracked knuckles won’t doom you to a life of joint pain and gnarly knuckles. But remember, pain and swelling should always be a cause for concern, along with any visible signs that something is off. But if you’re not experiencing any issues, go ahead and take a crack at it.