Ever since I can remember my joints have always been prone to popping and cracking. It was the worst when I was a child as I couldn’t really sneak around anywhere without my ankles loudly announcing my presence, thwarting my attempt at whatever shenanigans I was up to. Soon after I discovered the joy of cracking my knuckles and most other joints in my body, much to the chagrin of those around me. However even though I was warned of health effects (which I’m pretty sure is bunk) I never looked up the actual mechanism behind the signature sound and honestly it’s actually quite interesting:
Interestingly though whilst cavitation in the synovial fluid is one of the better explanations for where the sound originates there’s still some other mechanisms which can cause similar audible effects. Rapid stretching of ligaments can also result in similar noises, usually due to tendons snapping from one position to another. Some sounds are also the result of less benign activities like tearing of intra-articular adhesions tearing, although that usually goes hand in hand with a not-so-minor injury to the joint.
There’s also been a little more investigation into the health effects of cracking your knuckles than what the video alludes to. A recent study of 215 patients in the age range of 50 to 89 showed that, regardless of how long a person had been cracking their knuckles, there was no relationship between cracking and osteoarthritis in those joints. Now this was a retrospective study (in terms of people telling the researchers of how much they cracked their knuckles) so there’s potential for biases to slip in there but they did use radiographs to determine if they had arthritis or not. There’s no studies around other joints however, although I’d wager that the mechanisms, and thus their effects, are very similar throughout the body.
And now if you’ll excuse me I’ll be off to disgust my wife by cracking every joint in my body 🙂