“Air bubbles forming in the joint spaces are the most common cause of popping noises. This noise occurs at joints where there is a layer of fluid separating the two bones.
Joints can be forced apart through natural everyday movements, or deliberately, such as at the hands of an osteopath.
When this happens, the low pressure in the joint space causes gases within the synovial fluid (a natural lubricant in the joint) to form a gas cavity, which comprises oxygen, nitrogen and carbon dioxide…..”

What makes joints pop and crack and is it a sign of disease?

Clicking joints tend to run in families. Here’s what causes it.