Scientists from UC Davis Medical Center, USA, made it their goal to find out what impact the habit of cracking your knuckles has on your joints. Many people think it’s harmful, and our team is no exception.
What actually happens in the joint?
Roughly speaking, a joint is a place where two bones connect, packed in a joint capsule that is filled with liquid. When we crack our knuckles, the space between our bones expands. The joint liquid becomes insufficient to fill the gap, the pressure inside falls, and a bubble filled with gas appears. The sound we hear, therefore, is the pop of this bubble when it breaks.
In the second image, you can see a hollow due to extension of the joint.
Robert D. Boutin, a radiologist, and Robert Szabo, a surgeon, analyzed the data obtained from 40 test subjects. 30 had the habit of cracking their knuckles, while the other 10 subjects had never done this — at least not on purpose.
As it turned out, joint movement amplitude increases right after the crack, which means it’s a sort of warm-up for the joints. It might be a good prevention tactic for joint diseases, but this issue is yet to be researched.
The test also showed that those who like cracking their knuckles don’t suffer from swelling, arthritis, or other joint diseases.
However, despite all the pros of this habit, you should bear in mind that it may be a symptom of neurosis. And, of course, that it’s just annoying.