Snap, crackle, pop! Those sounds are usually associated with crisp rice cereal — but for some people, it describes the noise their joints make, too.
To someone cracking their neck, knuckles, or back, a pop may be a sound of relief. (To another person hearing it, it might be a whole different story.)
If you crack your joints, you’re in good company. It’s estimated that 25 to 45 percent of people voluntarily crack their knuckles, notes research. Of course, there are other joints that people crack intentionally, as well, such as the neck and back.
Here, we dive into what “cracking” actually means, if there are health risks associated with it, and how you may break the habit.
What Happens When You ‘Crack’ a Joint?
It’s a good thing that “joint cracking” isn’t a literal or medical term. The joint is bathed in synovial fluid, which is a thick liquid sitting between your joints that keeps them cushioned and comfortable as you move, per MedlinePlus.
Inside of the joint, there are small air pockets, which is normal, says Erin Nance, MD, a hand and upper extremity orthopedic surgeon and founder of Nance MD in New York City. “When you’re cracking your knuckles, the actual pop comes from the release of a bubble inside a joint,” she says. (That said, a review notes some researchers still aren’t sure if that cracking sound is the sound of the bubble being released, or not.)
By bending the joint in a certain way, you can express — or pop — that bubble, theoretically. With knuckles you might pull your finger straight out or bend the knuckle back, the latter of which creates negative pressure (making the space smaller), Dr. Nance says.
Either way, for many people, this might feel like a release of sorts. “We don’t have a clear scientific understanding of why cracking feels so good,” says Rahul Shah, MD, board-certified orthopedic spine and neck surgeon in Vineland, New Jersey. While it may relieve pressure that temporarily builds up in joints, the effect doesn’t last — and so, it becomes a habit.
Yes, You Can Hurt Yourself
The chief worry associated with cracking your joints? The potential to cause arthritis when practiced as a long-term habit.
From research, we know most about what happens over time when you crack your knuckles (as opposed to other joints). And, at least with regards to knuckles, you may breathe a sigh of relief:
“Cracking knuckles does not cause arthritis. Studies show that there are no signs of damage to the hands,” says Nance.
One study, published decades ago, looked at 300 patients who were older than age 45 and compared those who cracked their knuckles with those who did not. The result? Knuckle crackers were no more likely to have arthritis compared with a group who didn't crack. Furthermore, a more recent study found that knuckle cracking didn’t cause any immediate changes in the joint, though these joints potentially experience a decreased range of motion.
Cracking your knuckles may be a particularly benign habit, according to Nance, but there are ways that you might seriously cause harm. “Cracking” a joint in the wrong way can put pressure on the tendons, ligaments, or cartilage around a joint. “You can injure those structures if you push and pull in a way that a joint was not meant to go,” she says. That could lead to a strain or dislocation.
When it comes to your neck and back, keep in mind that there are other sensitive structures around this area — namely your spinal cord and nerves. “If cracking is too forceful, you can torque your neck or back too far,” adds Dr. Shah. As a result, you might pinch a nerve, injure a blood vessel, or strain a muscle, notes Houston Methodist.
And while more research is needed to better understand the effect of popping specific joints, it’s generally safe to say it may be smart to avoid developing a regular joint-cracking practice.
How to Get Out of The Joint-Cracking Habit
There are many reasons why you might crack your knuckles, but some people do so because it’s a form of stress relief or a nervous habit, says Nance. However, given that there’s a risk you could “crack” something in the wrong way, it’s worth it to find other ways to relieve stress and anxiety, she says.
Bring Awareness to Why You ‘Crack’ Your Joints
Pay attention if there are any patterns surrounding when and why you’re cracking, Nance recommends. That way, you can catch yourself or take action to avoid it. For example, if workday stress is building up, it might help to get up and walk around the office for a couple minutes or head outside for a five-minute break rather than sit at your desk cracking. “There are other ways to get through those periods of anxiety or boredom, if you’re doing it as a space filler,” she says.
Consider Exercises to Strengthen Your Joints
On the other hand, if you feel as if you have to crack any joint — knuckles, neck, or back — for that sense of physical relief, “this is not a sustainable solution, since you have to keep doing it over and over,” says Shah. Instead, he recommends strengthening muscles around the area to improve function and ability to absorb load. Visiting a physical therapist can give you an individualized plan, but there are also other safe exercises you can do at home.
For example, says Shah, for your neck, place your hand on your forehead and push your forehead into your hand; this will generate force that can strengthen your neck. Do the same while placing your hand behind your head and at your right and left ear. “If you have the desire to crack your neck, doing these exercises in addition to or in lieu of can be helpful. It’s a low-risk way to get good results,” he says.
If chronic back pain or stiffness is making you uncomfortable, physical activity, particularly resistance exercise and stretching and yoga, can help reduce (and prevent) back pain, as well as maintaining good posture and a healthy weight, according to the Office of Disease Prevention and Health Promotion.
When to See a Doctor
Certainly, if you crack something and feel pain, and are having trouble moving a joint like normal, or experience swelling, you should contact your doctor. These signs and symptoms may be an indication of a larger problem, such as a dislocation or arthritis.
However, there are other instances where you’d want to seek medical attention, too. One thing to keep on your radar is crepitus, which has a different feel and sound compared with run-of-the-mill joint cracking, Nance says. Crepitus is a grinding noise caused by arthritic bones rubbing against each other, she explains. This sound isn’t voluntary, meaning that you’ll hear it during everyday activities, not due to a self-induced pop. Though crepitus is more commonly associated with the knees, you can hear crepitus at the base of the thumb, which is the most common place to have arthritis in the hands, Nance explains. While cracking itself doesn’t seem to cause arthritis, that grinding sound may indicate the presence of arthritis, so it’s a good idea to get it checked out by a healthcare professional.
And if joint cracking is so frequent that it’s bothersome, that might be another reason to see a doctor to determine if there’s something else underlying going on.
Bottom Line
Most of the time, for most healthy people, occasional cracking is a relatively harmless habit — but experts still don’t recommend that you do it. “I think for many people, knuckle cracking is like a form of fidgeting,” says Nance. “There’s nothing inherently wrong with it, but there is a small risk of injuring yourself,” she says. For that reason, understanding why you’re cracking (out of habit, because of stress, or due to a potential underlying problem) can help you put a plan into place to stop the pop.
