athritis

Why Do Your Knuckles Crack?

Why Do Knuckles Crack?

Are you concerned that cracking your knuckles leads to joint degeneration?

Or have you ever wondered why your neck cracks (pops) whenever you stretch it?

The answer can be found in the
article published by the University of Alberta Faculty of Rehabilitation Medicine, PLOS One called, 'Pull My Finger Study'.

"A cavity is created and that event is what's associated with the sound"


With the aid of a MRI, a finger was slowly pulled until the knuckle cracked. It finally proved that when you stretch the capsule that surrounds a joint, a bubble forms in the synovial fluid which is responsible for the popping sound.

Check out the MRI study video:

Pull My Finger Study_YouTube


Leader author Professor Greg Kawchuk explains. "It's a little bit like forming a vacuum. As the joint surfaces suddenly separate, there is no more fluid available to fill the increasing joint volume, so a cavity is created and that event is what's associated with the sound.

"No evidence that knuckle cracking leads to degenerative changes"


The data fails to support evidence that knuckle cracking leads to degenerative changes in the metacarpal phalangeal joints in old age. The chief morbid consequence of knuckle cracking would appear to be it's annoying effect on the observer."


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