What happens when my spine goes "POP"?
We hear this question every day! A common fallacy is that the sound comes from bones clicking against each other as they move. Some people use the word "crack", as in "getting my back cracked," to describe this sound.
Unfortunately, this expression has probably scared off more than a few people from getting the chiropractic care they need.
Let's take a look at what really happens to cause that noise you often hear when you get adjusted.
- First, you must understand the structure of a joint.
- Where two bones come together, there is a smooth surface on each end which fits very snugly so that they can glide across each other.
- Inside the joint, between the two bones, is a fluid that allows the joint to glide easily and freely.
- Surrounding the joint on all sides are ligaments which hold the bones very tightly together and keep this lubrication fluid from escaping.
- These ligaments actually form a tight capsule that seals off the joint from the rest of the body.
- All fluids in our bodies have gases dissolved in them; for instance, oxygen is dissolved in the blood.
- The lubricating fluid of joints contains dissolved gases - primarily nitrogen.
- Whenever a stretch is applied to the joint, the ligaments that make up the joint capsule are also stretched.
- This causes the space between the two bones to get wider. The pressure which is normally exerted on the joint fluid is rapidly diminished.
- When you look at a bottle of soda water under pressure, it looks like regular water, but as soon as you open the cap and release the pressure, bubbles of gas start coming out of nowhere. This is because the gas was dissolved in the water and under pressure.
- In the same way, when the joint is stretched and the pressure is taken off, the inert gas dissolved in the joint fluid bubbles out of solution and makes a popping sound similar to the sound of opening a bottle of champagne.
- This can happen with any joint in the body: spine, shoulders, knees, and, of course, everybody's favorite - knuckles! After a joint has been "popped," it takes about a half hour for the gas bubble to become absorbed into fluid again.
- That is why you cannot pop a joint two times in a row without a few minutes wait in between.
Sometimes an adjustment will not cause a pop, which doesn't necessarily mean the adjustment wasn't successful or that the doctor didn't "get it." Research has shown that a joint must open up about 40 percent to create a popping sound. When there is no pop, it simply means that the joint was not opened far enough to cause bubbles to pop out of the joint fluid; BUT IT MAY HAVE BEEN OPEN ENOUGH TO RESTORE PROPER MOVEMENT TO THE JOINT.
When we adjust a joint, we are not trying to create a pop; we are trying to restore joint motion.