Joint Health: Myths or Facts

Myth: Cracking or popping your knuckles will not cause permanent joint damage, nor does it strain or over-extend the ligaments enough to cause arthritis. When you crack your knuckles, the noise is caused by a gas which is mostly carbon dioxide. The gas is dissolved in the synovial fluid that encapsulates most joints. As you pull on the knuckle joint, the walls of the joint capsule expand and lower the pressure on the fluid inside it. The gas comes out of solution suddenly, forms bubbles and causes the popping noise.