14 DAY TRIAL // You know that distinctive sound our knuckles and other joints in our body make when we crack them either on purpose or accidentally? Well, scientists have at long last figured out what causes it.
In a study published in yesterday's issue of the journal PLOS ONE, specialists with the University of Alberta in Canada and fellow researchers explain that the sound associated with a cracked knuckle is due to the sudden formation of a cavity inside the joint.
The scientists behind this investigation detail how, looking to solve this millennia-old mystery, they repeatedly cracked the knuckles of a member of their team, a chiropractor by the name of Jerome Fryer.
With the help of an MRI machine, the University of Alberta researchers and colleagues looked inside Jerome Fryer's body while pulling his fingers and documented the mechanism behind each and every of cracking knuckles episodes they managed to induce.
The specialists found that the popping sounds were caused by the formation of a space between the abused joints. To get a better idea of how this space forms, have a look at the video below.
“It’s a little bit like forming a vacuum. As the joint surfaces suddenly separate, there is no more fluid available to fill the increasing joint volume, so a cavity is created and that event is what’s associated with the sound,” explains study leader Greg Kawchuk.
New insights into joint health
Interestingly, it looks like figuring out why joints pop when we crack them isn't the end of the road for this team of researchers. Au contraire, they have some seriously ambitious plans for the future.
In the PLOS ONE report detailing their work, the scientists explain that, now that they know what happens inside our body when we crack our knuckles, they want to turn their attention to using their newly acquired knowledge to gain a better understanding of joint health.
Thus, the specialists admit to being a tad puzzled by the fact that, although cracking one's knuckles elicits considerable force, people who habitually pull their fingers suffer no damage to their joints.
As part of another research project now in the works, the researchers want to use MRI machines to document what happens with people's finger joints after they are cracked. The end goal is to learn more about how joints work and how conditions such as arthritis affect them.
“It may be that we can use this new discovery to see when joint problems begin long before symptoms start, which would give patients and clinicians the possibility of addressing joint problems before they begin,” says Greg Kawchuk.
