What Happens When You Crack Your Knuckles?


If someone cracks their knuckles, what is your reaction? Does it gross you out, or is it something you do yourself?

People have different reactions to knuckle-cracking. 25-45% of people have a habit of cracking their knuckles. Some of them pop their knuckles up to 20 times a day.

The question is:

Why Do Some People Crack Their Knuckles?

For some, knuckle-cracking is a nervous habit. Similar to nail-biting and chewing on pens, it helps relieve some of the stress the person is feeling.

But, it can also be due to the fact that when you crack a knuckle, you decompress the joint. This gives your finger better movement.

A lot of people just pop their knuckles out of habit. They might have picked up the habit as kids and got used to the looser finger movement that comes with it.

Now, whenever they feel like their fingers are stiff, they crack their knuckles.

Why Do Some People Hate The Sound Of Cracking Knuckles?

Have you ever heard of misophonia?

Misophonia is the hatred of sounds. Some people just hate certain sounds; it could be the sound of chewing gum or breathing, barking dogs, or high heels hitting a hard floor.

Another common misophonia trigger is cracking your knuckles. Some people hate it, others are just annoyed by it.

Some people are actually afraid of the sound of cracking knuckles. The fear of cracking knuckles is called condylacousticophobia.

What Happens When You Crack Your Knuckles?

When you pull your finger to crack a knuckle, you are stretching your joint.

To understand what causes knuckles to crack and what makes the sound, you need a short anatomy lesson.

Your joint is the place where two bones meet and are connected with tendons and connecting tissue.

Joints are covered by a capsule called the joint capsule or synovial capsule, which is filled with synovial fluid. The synovial fluid has dissolved gasses in it.

When you start cracking your knuckle, you stretch the joint, which lowers the synovial-fluid pressure. Now, all those dissolved gases come together and create a cavity or bubble within the synovial fluid.

The formation of this bubble is what causes the popping sound.

Is Cracking Your Knuckles Bad For You?

If you crack your knuckles, you’ve heard time and time again: “Don’t crack your knuckles, it’s bad for you.”

You must also be worrying if cracking your knuckles gives you arthritis.

To answer that question, Dr. Donald Unger cracked the knuckles on his left hand for 60 years, but not on his right hand. He didn’t develop arthritis on either of his hands.

Cracking your knuckles doesn’t damage your cartilage and, therefore, doesn’t cause arthritis.

It is bad to crack your knuckles if you already have arthritis, though. The weak or damaged joints that are a result of arthritis are more easily injured.

However, knuckle-cracking isn’t completely harmless.

Not exactly. Cracking your knuckles weakens your grip and leads to hand swelling.

Also, some people can tear their tendons based on how they crack their knuckles.

Knuckle-cracking also leads to functional hand impairment.

Why Can’t Some People Crack Their Knuckles?

Remember that short anatomy lesson I gave you at the beginning of this post? Well, it doesn’t differ from one person to another.

Everybody has the synovial capsule filled with synovial fluid in their knuckles. That means everybody has the capability to pop their knuckles.

Some people just need to apply more force to get the knuckle to pop, though.

Is that a good idea?

Probably not, because applying too much force on your knuckle can cause injury.

If you can’t crack your knuckles, don’t crack them. The people around you will thank you for it.

But Why Do You Have To Wait To Crack Your Knuckles Again?

After you crack your knuckles, you have to wait a while until you can crack them another time.

This is because of the bubble of gases that forms in the synovial fluid.

To crack your knuckle again, you’ll have to wait about 20 minutes for the gases to redissolve in the synovial fluid. The minimum resting time is 17 minutes, while it shouldn’t take more than 22 minutes to regain the ability to crack your knuckles.

How to Crack Your Knuckles?

Do you insist on annoying those around you, but don’t know how to crack your knuckles?

Don’t worry, we’ve got you covered.

Here are two ways to crack your knuckles:

  1. Pull your finger (one at a time) until you hear a pop.
  2. Make a fist and push down on one finger until you hear a pop, then move to the next finger.