🦴 Does cracking your knuckles damage your joints?

That sharp sound produced when cracking your knuckles: many see it as a harmful gesture for the joints, others consider it harmless. The subject has been the focus of scientific studies.

The characteristic sound comes from the normal functioning of the joints. The fingers contain synovial joints filled with a fluid called synovial fluid. This fluid contains dissolved gases, including carbon dioxide. When you suddenly separate two joint surfaces, the pressure drops. A gaseous cavity quickly forms in the fluid. It's this cavitation phenomenon that produces the sound.


Imaging studies have confirmed this mechanism. Real-time MRI observations have shown the formation of a bubble in the joint at the moment of cracking. Contrary to popular belief, the sound does not correspond to a bubble bursting, but to its formation. After the action, it takes a few minutes to a few hours for the gas to redissolve and for a new crack to be potentially possible.

The essential question concerns the long-term consequences. Several epidemiological studies have examined the link between this habit and osteoarthritis. The results show no clear association between cracking your knuckles and an increased risk of hand osteoarthritis. A study comparing people who have had this habit for decades to others who never had it did not observe a significant radiological difference.

This does not mean the gesture is completely harmless. Some research has observed, in people who crack their knuckles very frequently, a slight decrease in grip strength or moderate swelling of the joints. These effects remain limited and do not correspond to clearly established structural degradation.

It is also important to distinguish voluntary cracking from other joint sounds. A pop accompanied by pain, locking, or swelling may signal a different problem, such as ligament damage or inflammation. In this case, medical advice is recommended.

Based on current knowledge, cracking your knuckles does not seem to cause osteoarthritis or directly damage cartilage in a healthy person. The phenomenon is based on a reversible physical mechanism. The main drawback often remains social rather than medical. As with many repetitive gestures, moderation and the absence of pain remain the best guides.