The noise you here during a manipulation is a release of gases from the cavity of a joint. Joints have a cavity in the center of them, and as a person moves around gases build up in the cavities. For example, take your knuckle, when you pull on one of your fingers you will extend the joint. As you stretch the finger further it will actually open the joint slightly allowing the gases to escape making a popping noise. When a chiropractor adjusts or manipulates the spine or different extremities, they are taking the joint to the extent of joint play. Upon applying pressure and giving the adjustment the joints are opening slightly, releasing those gases and thus allowing you to hear a popping sound. It doesn't always happen and its not the actual movement of the bones you are hearing. The joints upon manipulation are only moving a matter of millimeters. Hope this helps.
Dr. Greg it is so wonderful to see you! Thanks for the explanation. I can handle it everywhere except my neck. They have to use that other thing because the neck thing is too hard for me. I hate the cracking thing.
