As a Monroeville Chiropractor, one of the most common questions I get is, “What is that cracking sound?” upon an adjustment. The follow-up question is then usually, “Does cracking cause arthritis?”
So let’s just clear this up nice and succinctly. The short version is as follows:
That cracking sound that is heard upon an adjustment (or more commonly when you crack your knuckles) is not your bones cracking. When two bones come together it forms a joint, and all of our joints in our body have a certain amount of fluid in them. When the joint becomes slightly fixated, i.e. not moving as well as it should, little gas bubbles form into the fluid. So when you move a joint in some way; whether it’s a Chiropractic adjustment, cracking your knuckles, or simply turning your head to back your car and you hear that audible crack, all that noise is are those little gas bubbles popping because the movement of the joint created enough friction to “pop” those bubbles. Ever notice how after you crack your knuckles that you can’t get them to make that cracking sound again for a while? That’s because those gas bubbles haven’t reformed yet in the joint.
So then to answer the second part of the question, no, cracking your knuckles, or any joint for that matter, does not cause arthritis. There have been many studies done on this, both true scientific studies and “layperson” studies, but they all conclude the same thing. I’ll cite a few of them here for your reference.
http://www.scientificamerican.com/article.cfm?id=crack-research
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1004074/?tool=pubmed
http://www.jabfm.org/content/24/2/169.long
So there you have it folks!
-- Dr. Brent Shealer – Monroeville, Penn Hills, Pittsburgh Chiropractor