One of life’s greatest mysteries (if you’re weird like me) has probably just been solved by scientists from the University of Alberta. The researchers have some of the first high-quality evidence for why your knuckles (and a lot of other joints in your body if you visit a quality chiropractor) “crack”. The experiment was performed on a chiropractor, Jerome Fryer using an MRI to see in real time as his knuckle was “cracked” by a gentle tug from a rope attached to his finger. The researchers foundthat as the volume of the joint capsule is increased, a small bubble is formed. While a sound recording was not available in the MRI machine the researchers reported that the formation of the bubble coincided exactly with the audible “pop” sound that we are all so familiar with. Kawchuk, one of the lead researchers for the study, and his colleagues didn’t observe any collapse of the cavity at all which contradicts a previous theory that the collapse of the cavity is what causes the noise.
The fact that the cavity did not collapse also lends credence to the idea that joint manipulation increases the spaces between joints which could have implications for treatment in degenerative joint diseases and other conditions of the joints. At least now now we have a reasonable explanation to why we hear that “pop” during manipulation and hopefully it will lead to further research about manipulation and joint health.
Are you a knuckle-cracker? Were you told that it would cause arthritis is make your knuckles bigger? Leave your experiences in the comments below.