In every issue of WebMD the Magazine, we ask experts to answer readers' questions about a wide range of topics, including some of the oldest -- and most cherished -- medical myths out there. For our October 2011 issue, we asked Dimitrios Pappas, MD, assistant professor of medicine at Columbia University's College of Physicians and Surgeons, about the long-term effects of one popular childhood activity: knuckle cracking.
Q: My 10-year-old son cracks his knuckles. Is it true that it causes arthritis?
If you think you have scleroderma, tell your doctor what symptoms you've noticed.
In order to make a diagnosis, he'll ask you about your family's health history, look for changes in how thick your skin is, and do some tests.
He may look at your finger under a microscope to check for changes in tiny blood vessels. These start to vanish early on in scleroderma. He’ll likely take a blood sample and send it to the lab to see if your immune system is in overdrive.
Your doctor may also take a small...
Ten-year-old boys love to make noises with their body, so it's not surprising your son is intrigued with the sound of a good knuckle pop. But you can put your fears aside -- the idea that knuckle cracking leads to arthritis is FALSE.
"There have been a few studies on this,” Pappas says. "None of them shows any change in the occurrence of arthritis between people who habitually crack their knuckles and those who do not.”
But here's something cool you can tell your son: The "pop” that comes when you compress your knuckles isn't from bone snapping on bone. It happens because, as the bones are stretched apart, a gas bubble forms and then pops.
While such joint cracking doesn't lead to arthritis, medical journals do contain reports of people who injured their ligaments while cracking their knuckles. At least one study also found the grip of people who habitually crack their knuckles may weaken over the years.