Good Question: What Happens When We Crack Our Knuckles?
MINNEAPOLIS (WCCO) -- It's a sound that can cause some of us to wince. For others, it relaxes the hands and the mind. Sharon from Apple Valley wrote us wanting to know: Is cracking your knuckles bad for you? What happens when we crack our knuckles? Good Question.
"They're not entirely sure, but MRI studies indicate that when you pull the two bones apart, you create a space in the joint that allows an air bubble to form," says Claire Joubert, a physician assistant with Twin Cities Orthopedic.
There's something called synovial fluid in between a person's joints. It's the color and viscosity of honey and helps, along with cartilage, to ease the movement of the bones. When a person stretches their fingers, the joint fluid doesn't expand. Instead, it creates space where the joint fluid isn't. That's where the gas bubbles form.
What's still up for debate among scientists is whether the actual cracking is when the bubble forms or when it pops.
Joubert says patients often ask her if cracking their knuckles is bad for you. Over time, rumors about that knuckle cracking causes arthritis or the knuckles to grow larger.
"No, none of that is true," says Joubert. "The only thing that's been demonstrated is that it's an irritant to those around us."
One California doctor named Donald Unger did his own experiment on this topic. For 50 years, he cracked the knuckles his left hand every day, but very rarely on his right. After five decades, he found the habit did not lead to arthritis or any apparent difference in his hands.