Cavitation

Cavitation: the formation of an empty space within a solid body or fluid.

• Mechanism of Sound Creation during Manipulation (a.k.a. cracking joint, popping joint, etc): Cavitation sounds result from the separation of joint surfaces, which results in a rapid decrease in intra-articular pressure (cavitation), which results in degassing of synovial fluid (mostly carbon dioxide), the creation of a cavitation bubble within the joint, and the sound itself is either the result of bubble collapse or bubble formation/tribonucleation. Note, research demonstrates there is no correlation between manipulations producing a cavitation sound(s) and manipulations resulting in a systemic neurophysiological response or improved patient outcomes.