Apparently, there are both mental and physical reasons behind why people have the urge to crack their knuckles. The real question though is, is it healthy?
According to Michael Suk, M.D., chairman of the department of orthopedic surgery at Geisinger Health System, “From a mental standpoint, it’s almost a nervous habit for some people, much like drumming their fingers or biting their nails. There’s a feeling associated with doing it as a mental stress reliever.
From a physical standpoint, I think what this study shows is as you create space in the knuckle, you’re decompressing the joint, so your finger feels less constrained.”
The Popping Sound
What exactly is going on inside your hand when you hear the popping sound your knuckle makes? It’s actually been a mystery that scientists have been trying to uncover for decades.
A study in PLOS ONE health journal explains that what you hear is the result of a bubble of air that forms when the joint in your finger is pulled apart.
They discovered this by reviewing a University of Alberta study that manually cracked a participant’s finger while receiving an MRI.
The MRI video clips uncovered that when the joint separates, a bubble forms in the fluid between the joints, and then everything settles back into place.
Ever wonder why you can’t crack your knuckles immediately after it has just been done? Well, Dr. Suk explains that “The fluid takes time to refill and create the same dynamics it had before.”
“It’s like pouring oil through a very small hole in an hourglass—it takes time for it to fill up again,” Dr. Suk adds.
Why Can’t Everyone Crack Their Knuckles?
It’s as simple as this, everyone has the capability to do it, but some can