When you crack your knuckles, gas is released. Where does this gas come from, and more importantly where does it “go” when cracked?

Question

When you crack your knuckles, gas is released. Where does this gas come from, and more importantly where does it “go” when cracked?

In: 100

Answer 1

Cracking your knuckles/joints is where nitrogen within synovial fluid (fluid found in the cavities of joints) is compressed and the joint is essentially stretched. This stretching causes the dissolved gas to release from the fluid due to the pressure from the joint stretching, causing the ‘crack’ or ‘pop’ we hear.

IIRC, the nitrogen gas dissolves back into the synovial fluid and the process repeats itself over and over for our enjoyment!