Roughly 40% of the US population habitually cracks their joints. If you are one of them, you will probably feel the urge to crack them by the time you finish reading this sentence. But with all the theories that it might be unhealthy and that it may have devastating long-term side effects, you are also wondering if it’s safe to do so.
What is joint cracking?
Joint cracking, or joint manipulation, is defined as passive movement of skeletal joints, mainly synovial joints such as finger, wrist, elbow, shoulder and neck joints. It is commonly used for therapeutic purposes by chiropractors and physical therapists. Joint cracking gives us temporary relief of musculoskeletal pain, temporarily enhances the range of motion and relieves us of that “stiff” feeling we get in our joints.
What causes that popping sound?
Scientists are still trying to crack that mystery (pun intended), but the prevailing theory suggests that small cavities of partial vacuum form in the synovial fluid surrounding the joint. The moment we apply pressure to our knuckles, those cavities rapidly collapse, resulting in a sharp sound. Those cavities are filled mainly by carbon dioxide, and while the CO2 reabsorbs back in the fluid, joints cannot be re-cracked.
My grandma told me I will get arthritis if I keep cracking my joints.
Don’t worry, my grandma tells me the exact same thing each time she overhears my cracking session. There is no scientific proof to support that opinion. On the contrary, there is proof that it DOESN’T cause arthritis. In 2011 a study was conducted by examining radiographs of 215 people aged 50 to 89. Experts compared the condition of joints of habitual crackers to the ones who don’t crack their knuckles, and came to the conclusion that knuckle cracking doesn’t cause arthritis.
So, can I keep doing it?
That’s entirely up to you. True, it doesn’t cause arthritis and you can put your grandma at ease (not that she’ll believe you), but there were some inconclusive studies suggesting that habitual knuckle crackers have higher chances of developing hand swelling and lowered grip strength over time.
I think most experts would agree that so far the worst known side effect of joint cracking is that it annoys people around you, so take that into consideration the next time you decide to showcase your joint cracking talents to your friends and family.