Joint cracking is the manipulation of joints to produce a sound and related "popping" sensation. It is sometimes performed by physical therapists, chiropractors, osteopaths [1] pursuing a variety of outcomes.
The cracking of joints, especially knuckles, was long believed to lead to arthritis and other joint problems. However, this is not supported by medical research.[2][3]
The cracking mechanism and the resulting sound is caused by dissolved gas (nitrogen gas) cavitation bubbles suddenly collapsing inside the joints. This happens when the joint cavity is stretched beyond its normal size. The pressure inside the joint cavity drops and the dissolved gas suddenly comes out of solution and takes gaseous form which makes a distinct popping noise. To be able to crack the same knuckle again requires waiting about 20 minutes before the bubbles dissolve back into the synovial fluid and will be able to form again.[4]
It is possible for voluntary joint cracking by an individual to be considered as part of the obsessive–compulsive disorders spectrum.[5][6]
- ^ Richard Boggs, Hammaming in the Sham: A Journey Through the Turkish Baths of Damascus, Aleppo and Beyond, 2012, ISBN 1859643256, p. 161
- ^ Shmerling, Robert H. (14 May 2018). "Knuckle cracking: Annoying & harmful, or just annoying?". How do we know that knuckle cracking is harmless?. health.harvard.edu. Retrieved 19 July 2019.
One study published in 1990 found that among 74 people who regularly cracked their knuckles, their average grip strength was lower and there were more instances of hand swelling than among 226 people who did not crack their knuckles. However, the incidence of arthritis was the same in both groups.
- ^ Can knuckle cracking cause arthritis?, Washington Post, by Lindsey Boer, 23 August 2024
- ^ Dvorsky, George. "Simulation May Finally Explain Why Knuckle Cracking Makes That Awful Sound". Gizmodo. Retrieved 30 March 2018.
- ^ Abouhendy, Wa-il; Jawad, Sudad (4 July 2013). "Compulsive Joint Clicking on the Obsessive-Compulsive Spectrum: A Case Report". The Primary Care Companion for CNS Disorders. 15 (4): PCC.13l01513. doi:10.4088/PCC.13l01513. PMC 3869608. PMID 24392256.
- ^ Johnson, A.; Linse, A.; Novoa, K. C. (6 April 2022). "A Tough Case to Crack: Diagnostic, Ethical, and Legal Considerations in Treating Compulsive Neck Cracking". Cureus. 14 (4): e23875. doi:10.7759/cureus.23875. PMC 9076044. PMID 35530890.