Why do our knuckles make noise when we crack them?

Question

what happens inside our knuckles that makes the craaaack sound appear.I hope all of you know what this means.

Answer 1

Cracking knuckles make a distinctive sound, and the feeling of having your knuckles crack can be addictive enough to become a habit. Old wives’ tales tell us that cracking knuckles causes arthritis, but what does science have to say? And what exactly makes that distinctive sound when knuckles crack? This article explores the scientific facts behind how and why knuckles crack, and what long-term medical fallout may result from cracking knuckles on purpose on a regular basis. Learn about the sound behind cracking knuckles, the reason why knuckles crack, and why some people’s knuckles crack more than others. Plus, discover whether frequent knuckle cracking can be a warning sign for (or cause of) joint problems down the road!

What Makes That Sound When Knuckles Crack?

The sound that cracking knuckles make is actually not a “crack” at all, but a pop! When your knuckles crack, it is due to air bubbles in the synovial fluid popping. Synovial fluid is a clear, thick liquid that surrounds every joint in your system, including each knuckle, providing cushioning and lubrication. When you stretch or bend a joint, actions that always precede a knuckle crack, you cause the bones of the joint to pull apart slightly. When this happens, the pressure of the synovial fluid drops, and bubbles start to form. As your joint gets stretched further apart, the pressure drops so low that the bubbles burst, creating the familiar noise of cracking knuckles! This process is called “cavitation.”

Is Knuckle Cracking Necessary?

So cavitation, aka pressure changes in the synovial fluid, cause knuckle cracking on a physical level. But why? Are there benefits that occur when knuckles crack, or is it just a strange quirk of the human body? Well, there’s a very good reason for knuckle cracking: after your knuckles crack, you’ll experience easier mobility in those joints! The stretching and bending of your knuckle joints that happens when you’re cracking knuckles helps to relax the muscles near your knuckle, and stimulates the nerve endings in those muscle tendons. That adds up to a feeling of increased comfort after your knuckles crack.

How Often Do Knuckles Crack?

After cracking knuckles, you won’t crack the same joints again for almost half an hour. Once the bubbles have burst, it takes at least twenty minutes for the gasses that were in the bubbles to fully redistribute themselves through the synovial fluid, a process that must be completed before bubbles can form again. If there aren’t any bubbles, there won’t be any knuckle cracking, so that’s why there’s a “recovery” period where you won’t hear or feel your knuckles crack! However, it can seem like you are cracking knuckles more often than every half hour: if this is the case, you may actually be hearing different knuckles crack. In many cases, it is easy to misidentify which finger has actually “cracked,” because they’ve all been stretched or bent at the same time.

Why Do Some People’s Knuckles Crack More Often Than Others?

Why are cracking knuckles an almost constant experience for some people, whereas others only feel the sensation once in a blue moon? As for the question of why some people have their knuckles crack more often than other people do, it is most likely due to a combination of genetic and behavioral factors. Genetic variation causes slightly different joint structure in different people, which can increase or decrease synovial pressure, making cracking knuckles more or less necessary. Plus, behavioral differences in how different people use their hands through the day can effect how often cavitation occurs, which determines how often knuckles crack.

Are Cracking Knuckles Related To Joint Problems?

Yes. However, the medical truth is that we’re not sure whether frequently cracking knuckles is a cause or a symptom! For years, common wisdom has held that cracking knuckles as a nervous habit in your younger years can lead to arthritis down the road. However, medical science has yet to confirm this idea. No link between cracking knuckles and arthritis has been established at all, so there’s no cause for concern on that front if you crack knuckles regularly. However, people who crack knuckles as a frequent and consistent habit do show some long-term damage, like minor soft tissue damage, and below-average grip strength. It hasn’t yet been established whether cracking knuckles causes this damage. More studies are required to determine whether people who feel the need to have their knuckles crack frequently are creating unnecessary ligament stress that causes damage, or whether the desire to crack is an attempt to ease ligament stress which is already present.

Answer 2

.In between the knuckle joints are what's called Synovial Capsules, which are filled with Synovial Fluid; they act as buffers that stop the joints wearing out. Within this fluid are air bubbles which, if compressed, implode and make that cracking sound you hear when you 'pop' your knuckles.

Answer 3

few years back i had read an article in newspaper.the reason for this was when we crak our nuckles the noise is generated due to some type of gas{i dont know the name,maybe oxygen}is reacted and released from our bones which then makes the noice.cracking our knuckles is not good as more the gas releases and makes noice more it weakens the bones.

Answer 4

Some people call it cracking, others call it popping your knuckles. It's air that pops out between your knuckles that makes that sound.

Answer 5

In response to it being bad to crack our knuckles.....is it good to hold in a fart? its really not a good comparison, but its actually good to crack your knuckles. The myth about getting arthritis..is exactly that, a myth.
If its a built up of "gas", than would it not be better to release it?

Answer 6

our knuckles make noise because our nerves become weak after a long work,so it becomes stiff,so when u crack the they become squeeze and they make a little noise

Answer 7

It's the air cracking when the cartlige crosses over the bone.

Answer 8

Gas bubbles.

Answer 9

the noise is caused by nitrogen bubbles in the synovial fluid.

Answer 10

there is a little bit of air in out kuckles