Joint cracking

Uncommon card · No. 167889

Joint cracking is the manipulation of joints to produce a sharp popping sound and a related, subjective sensation. It is sometimes performed by physical therapists, chiropractors, and osteopaths, in pursuit of a variety of outcomes. The cracking mechanism involves nitrogen gas that is dissolved in synovial fluid. When the pressure inside the joint cavity is quickly reduced due to mechanical expansion, nitrogen gas is released from the solution, leading to the formation of cavitation bubbles. When these nitrogen bubbles collapse, they create a cracking noise. It takes about 20 minutes for the nitrogen to fully dissolve back into the synovial fluid, which allows the joint to produce another set of cavitation bubbles and generate the cracking sound again. Voluntary joint cracking is sometimes viewed as a type of "tic" and has been linked to the spectrum of obsessive-compulsive disorder. Two relevant studies highlight this connection: Abouhendy and Jawad (2013) discuss compulsive joint clicking...

Read on Wikipedia · Image Jaysin Trevino from Evanston, IL, US, CC BY 2.0