You are here
Home > Engineer > Mystery behind knuckles’ crackle solved

Mystery behind knuckles’ crackle solved

yhe endoc
yhe endoc
Mystery behind knuckles’ crackle solved

The distinctive popping sound heard when cracking knuckles is caused due to a cavity forming rapidly inside the finger joints, scientists have established for the first time ever.
“We call it the `pull my finger study’ -and actually pulled on someone’s finger and filmed what happens in the MRI.
When you do that, you can actually see very clearly what is happening inside the joints,” said lead author Greg Kawchuk, a professor at the University of Alberta.
Scientists have debated the cause of joint cracking for decades, dating back to 1947 when UK researchers first theorised vapour bubble formation as the cause.
That was put in doubt in the 1970s when another team of scientists instead fingered collapsing bubbles as the cause.
The idea for the project was born when Nanaimo chiropractor Jerome Fryer approached Kawchuk about a new knuckle-cracking theory.
They decided to skip the theories and actually look inside the joint.
In every instance, the cracking and joint separation was associated with the rapid creation of a gas-filled cavity within the synovial fluid, a substance lubricating the joints.
“It’s a little bit like forming a vacuum.
As the joint surfaces 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,” Kawchuk said.
The therapeutic benefit or harm of joint cracking remain to be explored.

Leave a Reply