Mar 6 2013
What Is the “Popping” Sound from a Chiropractic Adjustment?

What is that “popping” sound? Many people are unfamiliar with the mechanism of the popping sound that occurs during a chiropractic adjustment. Some people are actually scared or nervous thinking that it is causing harm or that it well hurt or it is just “gross”. I have actually had people ask if the bone was breaking. The answer of course is a resounding no! Otherwise I wouldn’t have any patients.
Here is the mechanism: synovial fluid in your joints contains oxygen, nitrogen and carbon dioxide gases, approximately 80% is carbon dioxide. When a chiropractor adjusts, the joint capsule is rapidly stretched, which in turn increases the volume of the joint by 15-20%. This creates a sudden and rapid partial vacuum which causes the internal joint pressure to decrease. With this decreased pressure the gases rapidly release from the synovial fluid. As they reverberate through the fluid it causes the “popping sound”.
For you physic buffs this is Robert Boyle’s Law from 1662.
This is the exact same phenomenon that occurs when you open up a bottle of soda or champagne, except with the joint it is a closed system (gases do not escape into the atmosphere) and with the soda or champagne it is considered an open system as the gases do go into the atmosphere.
Once a joint “pops” it takes the gases about 20 minutes to return into the synovial fluid.
Try this: Crack a knuckle in one of your finger joints. Now immediately try it again at the same angle. It doesn’t pop. Wait 10-20 minutes and try again, this time it will pop.
What if the joint doesn’t “pop”?
Some patients think this means that the joint didn’t need to be adjusted, or that the joint didn’t move at all.
Imagine this:
A joint normally moves an inch when perfectly healthy.
Due to muscle tightness, adhesions and inflammation the joint only opens 1/4 of an inch.
To have the joint “pop” it must open 3/4 of an inch.
The chiropractor adjusts and opens the joint 1/2 an inch. No “pop”. But the joint still moved.
The result:
There is still benefit as the muscles will relax, adhesions will be broken and inflammatory chemicals will move out of the surrounding tissues, just not as efficiently as if the joint had been opened more. The more a joint is adjusted the more likely it will “pop” and thus increase the benefits of joint motion.
By the way:
Currently there are no studies that suggest “cracking” your knuckles or joint “popping” will cause arthritis.
Ask Dr. Lance Casazza about all the benefits of the proper joint motion and chiropractic care.
Dec 11 2013
What’s The Deal With Cracking Knuckles?
Ah yes the age old question. I thought that cracking your knuckles was bad for you? At least that is what my mother always said. And isn’t that popping sound that occurs during a chiropractic adjustment the same thing?
Quick answers: No; mom is often right but not always (sorry mom); and yes. Let’s take a closer look.
First off what is that sound? Synovial fluid in your joints contains oxygen, nitrogen and carbon dioxide gas. When a joint is rapidly pulled apart (think chiropractic adjustment or cracking your knuckles) the volume of the joint increases by 15-20%. This creates a partial vacuum (decrease in pressure) and the gas rapidly releases due to the pressure change. (Boyle’s Law, 1662). The ligaments of the joint that just got stretched out will slowly return back to a normal position and the gases will be compressed back into the synovial fluid. This takes about 20 minutes for smaller joints (hands) and longer in larger joints.
Try this: Crack your knuckles. Then immediately try again. No popping sound the second time. Now wait 20-30 minutes and try again. More popping.
The Missed Adjustment? Sometimes when you get adjusted there is no popping sound, why is that? Simple the joint was not pulled apart far enough and/or fast enough. This is typically because the patient’s muscles are too tight and will not allow the joint to be pulled apart.
Okay, so good or bad? Does cracking knuckles cause arthritis?
Previous studies had NOT shown a link between knuckle cracking and hand osteoarthritis. One study even suggested that knuckle cracking helped prevent osteoarthritis.
Knuckle cracking and hand osteoarthritis, Journal American Board of Family Medicine, April 2011.
This study involved 215 people, of whom 135 had x-rays that showed they had osteoarthritis in their hands and 80 did not (healthy controls). The participants were aged from 50-89 years; they all had an x-ray of the right hand during the previous 5 years.
The results:
None of them had evidence of neuromuscular, inflammatory or malignant diseases, factors associated with lower grip strength and hand osteoarthritis.
Cool Story! Dr. Donald Unger spent 60 years cracking the knuckles of his left hand but never his right. He reported no arthritis or other problems in either hand. He earned the Ig Nobel Prize in Medicine for this in 2009.
So there you have it, that popping sound is not bad for your joints.
See you soon…
If you have more questions about the organic foods and the benefits of chiropractic just ask: Dr. Lance Casazza.
By Dr. Lance Casazza • Chiropractic Treatments, Health and Wellness, Pain Management • Tags: Cracking joints, Ig Nobel Prize, Joint, Osteoarthritis, Popping, Spinal adjustment, Synovial fluid, United States