Science determines mysterious source of that knuckle cracking sound


#1

Originally published at: https://boingboing.net/2018/03/29/science-determines-mysterious.html


#2

Now they just need to explain why it feels good.


#3

This is not a new discovery.


#4

Yeah, this isn’t news.


#5

But is it good or bad for me?! The debate rages on…much like debate on Eggs.


#6

Yeah, I read about this several years ago and the article even suggested cracking knuckles may be beneficial. I’ve been cracking guilt free ever since.


#7

Goddam, but I <3 cracking my knuckles!

Ain’t no debate… just silly superstitions.


#8

History is in the article:

Although experts had initially linked the sound to the collapse of knuckle bubbles back in 1971, their findings were thrown into question after further studies showed there were still bubbles left in the fluid after the knuckles had been cracked.

But the mathematical model appears to resolve this apparent contradiction by showing the sound can be produced by partial collapse, the researchers said.

Earlier studies using ultrasound had reached a similar conclusion linking the sound to changes in pressure in the joint fluid.

A 2015 paper suggesting it was actually the formation of a bubble rather than its collapse which caused the distinctive crack.


#9

It’s not a mystery. It’s coming from my freaking kid! All the time! Always!


#10

yeah…that’s what someone said about Eggs up until 1956 and now look where we are. Every 3 years the story changes!!!

I NEED ANSWERS!


#11


#12

I’m a very “poppy” person. Anecdotally I’ve found that Fish Oil makes my joints not pop randomly, only when I actually feel the need to pop that joint. It helps in meetings when I’m not clicking with every minor movement. My doctor seemed confused when I told him why I took the fish oil pills.


#13

I can answer that one I think.
The cracking of knuckles is no good for eggs.


#14

Collapsing cavitation bubbles can cause a high velocity jet that can damage boat propellers and carbon leaflets on artificial heart valves. The connective tissues around a joint are softer (excepting the bone of course) so maybe they yield to the jet and avoid damage, but one wonders.


#15

If you just want to know if it’s dangerous to your health, I can assure you it is if you do it within earshot from me.


#16

Science determines mysterious source of that knuckle cracking sound

I tried to keep the noise down, but I guess they found me.


#17

“The sound that is generated when one cracks his or her knuckles is due to the partial collapse of a cavitation bubble that’s in the fluid in the joint,”

Result of prolonged cavitation in a pump:

:smiling_imp:


#18

I’ll take my chances.


#19

I suspect living tissue has better regenerative capabilities than a pump. Not perfect, but possibly good enough.


#20

I heard the same thing in the 1990s.