What really happens when you ‘crack’ your knuckles?

Question

I love to crack both my knuckles and my back when I’ve been stiff for a while. I’ve heard something about it being gas escaping, but where does that gas go? Does it release into your body in some way?

Any insight into it would be awesome!

In: Biology

Answer 1

The joints that “crack are filled with a slick liquid called synovial fluid to help lubricate the joint. Sometimes they get air bubbles and when you hyperextend that joint it pops the air bubble when makes the pop or crack sound.