 So what is that loud crack or popping sound that happens with chiropractic adjustments? It has been investigated and studied using what we call cine radiography, which is a fancy word for a video x-ray. It appears that when joints are quickly separated, some of the fluid in the joint temporarily turns into a bit of a gas. So I can put my hands together and if I pull them apart, essentially what happens right after that is that joint has a little more space and moves a little bit more freely and that may be part of the mechanism by which the nervous system will send out information to your nerves and your brain and says this area moves better, it doesn't hurt as much, then that's part of the healing process.