Apparently there are both mental and physical components to 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 recent study 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 participants 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 immediate 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.”
Why Can’t You Crack Your Knuckles?
It’s as simple as this, everyone has the capability to do it, but some can do it much easier than others. “Some people have a lower threshold of pressure for separating them, but others require much more force to create the separation,” says Dr. Suk. It is suggested though that you crack your knuckles with caution as, “There have been some reports that people can tear or stretch tendons based on how they crack their knuckles,” says Suk.
So Is It Healthy?
There are plenty of unverified beliefs that cracking your knuckles will cause harm to your health. For instance many believe that the price of cracking your knuckles is arthritis. Several studies have actually found that habitual knuckle cracking is not linked to arthritis in the hands. So crack away, but be gentle!