Why Does Cracking Your Knuckles Make So Much Noise? Science Finally Has an Answer

There aren’t any awards to be won for solving science’s minor mysteries—why yawning is contagious, why puppies make us melt—but that doesn’t mean we don’t want the answers anyway. Add to those everyday puzzles the matter of knuckle-cracking. Why, exactly, should some of the body’s smallest joints produce such an outsized racket? Now, a study in Scientific Reports at last provides an explanation. It’s a theory that was first posited as long ago as 1971, but had been furiously debated (as these things go) ever since. Thanks to some creative thinking and a new mathematical model, however, the matter may have been settled. The authors of the paper—an pair of researchers from Stanford University in California and the Ecole Polytechnique in Palaiseau, France—begin with a quick review of the knuckle-cracking literature (yes, such a thing exists). In 1939, the leading theory was that the cracking sound was a result of a tightening of the fibrous capsule surrounding joints after so-called articular release—when the joint is adjusted or moved at a certain angle or to a certain degree. In 1947, that gave way to the theory that the signature cracking sound was caused by vibration in tissues when joints are moved beyond their usual range. But it was in 1971 that the knuckle-cracking field had its eureka moment, when a team of researchers from the University of Leeds announced that knuckle-cracking is caused by the collaps...
Source: TIME: Health - Category: Consumer Health News Authors: Tags: Uncategorized healthytime onetime Research Source Type: news