TY - JOUR T1 - Cracking the Cracked Knuckle: A Medical Student’s Take JF - The Journal of Rheumatology JO - J Rheumatol SP - 2624 LP - 2624 DO - 10.3899/jrheum.090530 VL - 36 IS - 11 AU - JOHN GAETANO Y1 - 2009/11/01 UR - http://www.jrheum.org/content/36/11/2624.1.abstract N2 - It may be in genuine consideration for another’s health, or it may be a selfish attempt to alter the behavior of another. Regardless, many have been warned that the continuation of this custom, whether it ranges from the casual offender to those bordering on ritualism, will inevitably suffer longterm sequelae. The old story that prolonged habitual knuckle-cracking leads to arthritis may now be considered a myth. In addition to an examination of the effect of this behavior, an attempt will be made to unravel or perhaps further tangle another issue: what is the cause of the sound created when one has cracked a knuckle? The majority who have offered an explanation for the cause of the sound uphold that the “crack” can be explained by a collapse of synovial fluid vapor cavities that result from the negative pressure induced by metacarpal-phalangeal (MCP), proximal interphalangeal (PIP), or distal interphalangeal (DIP) joint distraction1. Authorities who have studied the effects of knuckle-cracking rely upon this common … Address correspondence to Mr. Gaetano; E-mail: john_gaetano{at}nymc.edu ER -