It’s the old adage you probably heard a thousand times growing up.
But by now you've probably figured out that your face won’t really stick that way if you keep making that face, and the watermelon won’t grow in your tummy if you swallow the seeds.
So will you really get arthritis if you crack your knuckles? Or is that an old wives’ tale, too? We've all been told that joint popping can cause arthritis, so let’s look at it, and see what’s true…
Why Do People “Pop” Their Joints?
Much to the dismay of annoyed spouses everywhere, joint popping is incredibly common.
While no one has done an official study on how common joint cracking is, some estimates are as high as 25% of all Americans – which means as many as 1 in every 4 people are joint crackers.
Some people say it feels good. Other people do it out of habit. But for whatever reason, a lot of us are joint crackers.
So whether you've cracked your knuckles for years, do it as a nervous habit, or hear the occasional pop or crack when working around the house – you’re not alone in wondering what cracking actually does to your joints.
So What Happens When You Crack Your Knuckles?
Most people crack their joints one of three ways – bending them backward or forward, turning them sideways, or pulling on the bones around the joint. And while any joint can be popped, many people pop the knuckles in their fingers.
To understand what this popping noise means, you must first have a basic understanding of how joints work…
Your joints are formed where two bones come together.
The ends of each bone are wrapped in cartilage and the cartilage is inside the joint capsule.
The joint capsule is filled with synovial fluid. This synovial fluid is what supplies the nutrients your joints need, as well as keeping them lubricated and moving smoothly.
But this synovial fluid also contains dissolved gasses: oxygen, nitrogen, and carbon dioxide.
When you crack your knuckles, the pressure causes these gasses to release from the synovial fluid and creates the cracking or popping sound you hear.
Think of it as a can of soda. When you crack the lid, you hear the fizzing sound of air escaping the can.
The exact same thing happens each time you crack your knuckles. That “pop” you hear is simply the gas or air escaping from your joints.
It seems strange, sure. But that’s exactly what happens each time you crack your knuckles.
But Does Knuckle Popping Cause Arthritis?
In light of this question, and the confusion surrounding it, researchers from the Uniformed Services University of the Health Sciences decided to answer the question once and for all.
In studying 214 people, 20% of them popped their knuckles regularly. Of those 20%, 18.1% of the knuckle crackers had arthritis in their hands. However, 21.5% of the study participants who did not crack their knuckles also had arthritis in their hands.
So basically, the odds of having arthritis are the same whether you crack your joints or not.
And to put it even more simply, joint popping does not cause arthritis. In fact, many highly respected medical facilities and sources, including Harvard and the Johns Hopkins Arthritis Center, have come out definitely stating that joint cracking doesn't cause arthritis.
So, Cracking Your Knuckles is Safe Then?
Not necessarily. While joint popping may not cause arthritis, it is not completely risk-free. In at least one study, chronic joint popping was shown to cause inflammation and weakened grip in the hands.
Another study, performed by the Department of Internal Medicine, Mount Carmel Mercy Hospital, in Detroit, focused on 300 participants. 74 of them cracked their knuckles, while 226 did not crack their joints.
Both groups showed similar rates of arthritis in their hands, however, the 74 who cracked their joints showed a higher rate of inflammation of the hands, and a weaker grip. So, while joint cracking may not cause arthritis, it can still have a negative impact on the overall health and strength of your hands.
If you are one of the 1 in 4 people who pop your joints, you can relax. Joint cracking won’t give you arthritis. Now, whether it annoys your wife or husband is a whole different question…