But that is an old wives’ tale. Habitual knuckle-cracking won’t cause osteoarthritis or joint enlargement.
Cracking your knuckles releases gas, in the form of nitrogen bubbles, from the space around your joints. The sound is triggered as the bubbles are compressed.
That said, the sound can make some people cringe. And a 1999 study found weaker hand grips and more hand swelling among knuckle-crackers.
— Orthopaedic surgeon Kim L. Stearns, MD