Joint cracking refers to the manipulation of joints to produce a sound and related “popping” sensation.
Cracking finger joints makes a distinct cracking or popping sound.
The cracking of joints, especially knuckles, was long believed to lead to arthritis and other joint problems, but this is not supported by medical research.
The cracking mechanism and its resulting sound is caused by dissolved nitrogen gas cavitation bubbles suddenly collapsing inside the joints.
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 crack the same knuckle again, requires waiting about 15 minutes before the bubbles dissolve back into the synovial fluid and will be able to form again.
Joint cracking can be considered as part of the obsessive–compulsive disorders spectrum.
The snapping of tendons or scar tissue over a prominence can also generate a loud snapping or popping sound.
The claim that cracking one’s knuckles causes arthritis is not supported by scientific evidence.