What is the sound when I am adjusted? Often patients will hear a "pop" during a traditional chiropractic adjustment, and sometimes during a Cox Technic flexion-distraction adjustment. This "pop" is called a cavitation. This cavitation is simply a release of gases (oxygen, nitrogen, CO2) from the facet joints of the vertebral segments which contain synovial fluid. Synovial fluid lubricates the spinal segments for movement. Consider opening a soda bottle that is dropped. When opened, there is a loud snap and rush of bubbles. The cavitation is similar, but contained.« View All FAQs"This information and website content is not intended to diagnose, guarantee results, or recommend specific treatment or activity. It is designed to educate and inform only. Please consult your physician for a thorough examination leading to a diagnosis and well-planned treatment strategy. See more details on the DISCLAIMER page. Content is reviewed by Dr. James M. Cox I."