The term “cracking” when referring to joint cracking is the popping sound that occurs when quick motions loosen the joint and ligaments of that joint. (A ligament is a short band of tough, flexible, fibrous connective tissue that connects two bones or cartilages or holds together a joint.)
Any joint can be “cracked” and it is common for people to also crack their knuckles, lower back, hips , ankles and toes.
The joint will make a cracking sound for three reasons:
1. Escaping gas:
There is fluid in the joints that helps the bones and tissue to move together smoothly. This fluid contains oxygen, nitrogen and carbon dioxide.
When the joint capsule is stretched, gas is rapidly released in the form of bubbles. This release of gas makes a popping or cracking sound. This process is also referred to as “boiling” or “cavitation”.
2. Movement:
When a joint moves, it also affects the tendons and ligaments, which are the fibers connecting the bones and muscles in the joint. (A tendon is a tough fibrous tissue that connects a muscle to a bone.)
If a tendon moves slightly out of place, it can make a snapping noise when it returns to its original position. Similarly, the ligaments can tighten when the joint is moved and can make a cracking sound. This will often occur in the ankle or knee.
3. Arthritis:
If a joint is affected by arthritis, the cartilage can lose its smoothness. As the joint surface become rougher, it can make a noise when it moves.
When a chiropractor moves a joint, that “cracking sound” may or may not occur. It is not the bone moving but just the sound of the releasing gas. Also, the chiropractor is putting motion into the joint and allowing the joint to go back into place. When a person “cracks” the joint himself he may just be releasing gas from the joint and not really “adjusting” the bone as the chiropractor does.
Source: Medical News Today
When a bone goes out of place it does not usually “pop”. So, when the chiropractor moves the bone, it does not have to “pop”. The technique Dr. Waugh uses checks the bone to make sure it went back into place whether it makes a “pop” or not.
A more gentle adjustment may or may not make a noise. The noise is not the bone going into place but the quick change in joint pressure.
I know patients like to hear that “pop” and it feels good. But, anytime you move a bone, endorphins (natural pain relieving substances in the body) are released. This occurs whether there is a “pop” or not.
The adjustment also affects brain function in a positive way by relieving interferences to the nervous system. More research is being conducted on how the adjustment affects brain function.
