
A simulation reveals just what is making the satisfying ‘pop’ noise when you crack your knuckles.
I mean, I have to say, the use of ‘satisfying’ here is certainly subjective, as for some of us, that cacophony of pops when you stretch out your interlaced fingers can be horrific.
We don’t all like the same stuff, you know?
But whether you’re a fan of the cracking or not, you’ll likely have bought into the myths and conspiracies growing up over just what is actually happening in your joints.
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Despite what we might have believed or been told on the playground, it turns out there isn’t actually much scientific evidence to suggest cracking our joints is bad for our health or that it ‘causes’ or directly leads to arthritis.

So, as the crack addicts know, that popping noise can happen when moving various joints, tendons and ligaments all around the body.
And rather than being the noise of the actual bones cracking away (as our younger selves may have once been warned), the noise basically comes from the popping of little bubbles.
As a simulation by Angelo Motion on YouTube shows, our joints contain a fluid called synovial fluid, and this protects our bones from grinding away against each other.
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The fluid also contains oxygen, nitrogen and carbon dioxide, with gas often forming when you’re stretching the likes of your fingers. Then, when you ‘crack’ them, the gas bubbles escape from the synovial fluid.
Plenty of people finally making this realisation thanks to the simulation commented that they soon found themselves feeling as though they needed to crack their knuckles… when you get that itch, you just gotta crack, I guess?
Plus, this understanding of gas bubbles building up and then collapsing or bursting explains why you can’t crack the same knuckle straight away, because it’ll take some time for them to accumulate again in the joint.
While it is said to be harmless, if you find that your joints are regularly cracking and are accompanied by pain, swelling or other symptoms, then you should head to your GP or get advice from a healthcare professional.
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The same goes for if you’re experiencing pain and feel as though the only way you can relieve it is by cracking parts of your body.
Both of those instances are pretty different to just mindlessly cracking your knuckles now and again while your co-workers squirm over the sound from across the desk.