A. Gas
B. Muscles tearing
C. Skin being pulled
D. Bones clinking
Details About Why Do Our Knuckles Crack:
The sound of cracking knuckles is caused by nitrogen gases that build up in our bodies and form bubbles between each joint. These bubbles will burst and produce noise when you crack your knuckles or any other bone. Everyone is affected differently by this; some people can crack them every 15 minutes, while the average person may crack them five times a day.