You know how people love to crack their knuckles, or how sometimes when you get up from your chair, your knees make a slight crack? Well, that’s because joints can crack naturally and also from manipulation—but is it really okay to be cracking them so much?
What Does That Cracking Mean?
Here’s what’s happening: “When you twist, pull or ‘crack’ a joint, you are essentially increasing the amount of space between your bones,” says Dr. Robert Glatter, MD, an assistant professor of emergency medicine at Northwell Health and attending emergency physician at Lenox Hill Hospital.
As expansion happens, it leads to negative pressure, which then pulls joint fluid into this newly generated space, he explains, as well as some carbon dioxide gas.
“When the liquid is placed under pressure and force is applied to the joint during the ‘cracking,’ the gas exits and creates a ‘pop-like’ sound,” he explains.
So, “the cracking or popping sound you feel and hear when you crack your knuckles is actually a combination of two processes: the rapid movement of fluid generated by this negative pressure gradient, but also the exiting of gas that produces a popping noise,” he says.
Is It Dangerous?
That pop can sound alarming, but don’t worry about it too much. If you’re cracking your knuckles, it might be a bad habit, but you’re totally fine.
“Cracking your knuckles will not harm or injure your joints and will not lead to osteoarthritis,” he says. “A number of studies have looked at people who have routinely cracked their joints among large groups of osteoarthritis patients. The evidence did not indicate that people who crack their finger joints are more likely to develop arthritis compared with those who never cracked their knuckles,” he says.
In fact, a more recent study noted that people who cracked their knuckles had the same levels of swelling, ligamentous laxity, degree of weakness, and joint mobility (meaning the joints move beyond a healthy range), compared with those who did not crack their knuckles.
Yet—be wary of the back and neck. “Cracking your neck or back is not the best way to protect your spine,” he says. “One of the risks with doing this on your own is that it may lead to excessive mobility of your joints, which in turn could lead to increased pain with repeated cracking and self-manipulations,” he says
What’s The Takeaway?
Unless you really need to crack your back, try not to, or find a chiropractor you can trust who knows proper technique. “One of my main concerns in having others crack your back—or even step on it—is the increased risk of injury,” he says.
When someone who is untrained tries to crack your back, the risk of a muscle strain or tear goes up significantly. Asking a friend to stand or walk on your back really isn’t wise, even if you think it’d make a great Instagram post.
“To begin with, it involves a significant amount of weight concentrated in a small area,” he says, and it can lead to spinal muscle injury, vertebral fractures or even injury to the abdominal or pelvic organs.
Regardless, proceed with caution on these areas, and always tell practitioners of any sensitive spots or previous injuries or conditions.