It is a pleasurable sensation for some, and terrifying for others. It might be the sound, or the relief that follows. Knuckle cracking has been associated with arthritis for years, but there is not a single study that supports that association. In fact, a study from the University of Alberta would be confirming one of the many theories about the origin of the sound, and would indicate that, in reality, cracking your knuckles could be something good for us.
Every time I wake up. Sitting in bed, I turn my head to the left. “Crack!”. A distant voice shouts at me: “One day you'll end up stiff!”. But it hasn't happened yet, or otherwise everyone would look like the Leaning Tower of Pisa. Both my neck and knuckles are a real concert in my case. Other people achieve that effect in different parts of the body, but the first sensation is always the same.
What just broke in there? Fortunately, nothing breaks. More than once we have heard horror stories about knuckle cracking, with people who (supposedly) only grew up to have crooked fingers and useless hands. Arthritis has also been mentioned ad nauseam, however, there is no evidence.
The origin of the knuckle-cracking sound
The knuckle-cracking sound generated for decades a wide debate among doctors and researchers. The number one candidate is cavitation. Upon slight separation of the joint, the synovial capsule that surrounds it increases in volume. This causes a low-pressure environment, and causes the gases in the synovial fluid (carbon dioxide, nitrogen, and oxygen) to separate from the fluid, forming a bubble.
The origin of the sound is the formation of the cavity and bubble, not its collapse. The gases need between 10 and 30 minutes to be reabsorbed by the synovial fluid, and that is why cracking your knuckles is not something you can do constantly (there are exceptions, of course).
A recent study from the University of Alberta manages to tip the scales in favor of cavitation by recording under magnetic resonance imaging what happens when a person cracks their knuckles, all in an interval of 300 milliseconds. But the most interesting thing is that the process could be beneficial, since it would help keep the joint lubricated, which is what we all want.
This idea goes against general thinking. Now, most sources agree on one point: If the crack is accompanied by pain and happens during normal joint movement, there may be a problem, so it is advisable to consult a doctor.
