Kids were warned that cracking their knuckles would damage their joints and inevitably lead to arthritis as they aged.
Cracking joints is caused by the formation and collapse of gas bubbles in synovial fluid, not cartilage damage. Long-term studies show no link between joint cracking and arthritis development. Some habitual crackers may develop reduced grip strength over decades, but the evidence for arthritis is nonexistent. The sound is dramatic but harmless. Parents often used this myth to discourage an annoying habit rather than out of medical concern.
Reception
Sources
- Snopes: Knuckle Cracking PRIMARY
- Wikipedia: Cavitation REFERENCE
- Mayo Clinic: Knuckle Cracking REFERENCE