Do you know what causes the cracking or popping noises you often hear during a manipulation (or adjustment) to your spine? We call those noises ‘cavitations.’
A recent study asked regular people what they thought caused the noises during manipulation. The top two answers were: they’re caused by repositioning of the vertebrae (the bones that make up your spine) (49%), and they’re caused by friction between two vertebrae (23%).
But we’re not repositioning bones or ‘putting the joint back in’ during a manipulation, although it can feel like that sometimes. And bones rarely rub directly against each other, there is almost always other tissue in the way like lubricating fluid, cartilage, fat, and ligaments.
Only 9% had the right answer! The noise actually comes from the really rapid formation and collapse of a gas bubble inside a joint when it’s stretched, and it’s perfectly safe. For the science junkies, this process is called ‘tribonucleation!’