Cracking your knuckles or other joints is pretty satisfying for some and annoying for others–but is it bad for you?
You might have heard the warnings and old wives’ tales: It leads to arthritis, it’ll make you have “fat fingers,” or popping certain joints in your neck and back might even lead to having a stroke or worse in the long-term.
The science behind the “popping” noise that joints make is not exactly well-understood, but there’s several theories as to why joints crack.
According to Johns Hopkins University, one theory is that nitrogen bubbles in the fluid inside the joint are released rapidly as the joint is manipulated in a certain way.
The joint liquid, more specifically, is called synovial fluid, and it works to lubricate the articular cartilage of synovial joints during movement–the same way motor oil in a car’s engine reduces friction. As you pop your joint, you stretch the joint capsule, and it then releases the gas, which forms bubbles, according to the National Institute of Arthritis and Musculoskeletal and Skin Diseases.
That’s why when you try to crack the same joint again, you have to wait for a bit because the gases have to come back to the synovial fluid.
The Institute notes there’s another theory about the sound is because the ligaments (the tissue that holds bones together) make the noises if they get tight rapidly as the joint moves. As it moves, the position of the tendon changes and moves out of place. As a result, one might hear a snapping sound as the tendon returns to its original position. Also, your ligaments might tighten as you move your joints, which is something that commonly occurs in your knee and ankle–making the cracking sound.
And while some people aren’t too fond of the sound of popping joints, research has shown that it’s neither harmful or beneficial.
“Cracking and popping of joints is usually normal and most of the time is nothing to be concerned about,” says the university. It doesn’t cause arthritis, either.
However, if you’re experiencing pain, you might want to stop doing it, and you should get it checked out.
That pain could mean there’s “underlying abnormalities of the structures of the joint, such as loose cartilage or injured ligaments. Some patients with arthritis (inflammation of joints, usually painful), bursitis, or tendinitis notice ‘cracking’ sounds due to the snapping of irregular, swollen tissues,” says WebMD.com in an explainer.
Also, swelling isn’t normal and needs a medical evaluation, says Johns Hopkins University. If your joint is getting locked or stuck when it pops, it might indicate a joint problem. And, if you’re losing motion in the joint, medical treatment is probably required.
Photo credit: Jaysin Trevino, Flickr