The fluid contains the gases oxygen, nitrogen, and carbon dioxide. When you pop or crack a joint, you stretch the joint capsule. Gas is rapidly released, which forms bubbles.
The gas released after cracking your knuckles is nitrogen gas, which forms bubbles in the synovial fluid surrounding the joints.
Knuckles "crack" because gas builds up in the joint and is released when you apply pressure to it. So really cracking is not a correct term. Release of gas is.
When you crack your knuckles, the sound is produced by the release of gas bubbles—usually nitrogen—from the synovial fluid in your joints. This gas is released due to changes in pressure within the joint, creating a cracking sound.
The sound you hear when you crack your knuckles is actually the sound of carbon dioxide gas bubbles bursting.http://en.wikipedia.org/wiki/Knuckle_cracking
It's O.K. to crack your knuckles. Really, you're not cracking them, you are simply pulling the joint and when you get that sound, that's a gas that's being released. No trauma or damage to the joint is done.
Bubbles of Gas
No. Your knuckles crack because of gas bubbles formed in the joints under pressure.
Cracking your knuckles releases a gas that naturally forms in your joints. Cracking them isn't bad for you unless it causes pain.
No, cracking your knuckles does not make your hands bigger. The sound you hear is caused by gas bubbles being released from the fluid that lubricates your joints. It does not have any impact on the size of your hands.
When you crack your knuckles, your bones are rubbing together. That's what makes the cracking sound. It used to be beleived that cracking your knuckles caused arthridis, but that been prooved untrue.
I'm not sure but when you crack your knuckles it releases the gas from your joints It doesn't hurt you if you stop (even though I do). There may be rumors saying knuckle cracking leads to arthritis but there is no concrete evidence supporting this. CRACK AWAY!
It is caused by a gas being released from a part of your knuckles ;D