How Does Here's what happens to your knuckles when you crack them Work?

When you crack your knuckles, it’s like popping a bubble inside your fingers.

Knuckles are the parts of your fingers where the bones meet, kind of like the hinges on a toy door. Inside each knuckle, there's a little pocket filled with fluid, and when you stretch or bend your finger, that fluid gets squished into a tiny space. That makes a bubble form, just like when you blow soap bubbles in the bathtub.

If you hold that bubble for a while, it can get bigger, and then snap!, it pops, and you hear the crack. It’s just like when you pop a balloon, whoosh!, all the air rushes out in one go.

Each time you crack your knuckles, you're making that bubble pop again. It's kind of like opening a soda can, every time you press the button, it makes a ping and fizzy stuff comes out. Your knuckles work the same way, just with bubbles instead of soda!