What is the "clicking sound" when I get an adjustment?
Chiropractors adjust the facet joint (apophyseal joints/zygapophyseal joints) of the spine. The facet joint has a synovial capsule which gives it lubrication and nourishment. The capsule is surrounded by fluid and gas bubbles. The fluid in the synovial capsule is made up of gases such as oxygen, carbon dioxide and nitrogen. The clicking sound that you hear when you receive a chiropractic adjustment is a result of gas bubble coalescence, or gas bubble collapse and fluid movement within the synovial capsule of the facet joint. This is known as a cavitation.
It is a safe and effective treatment for restricted joints, meniscoid entrapments, back pain arising from the spine and various other conditions related to the spine. Adjustments/manipulation can also be performed in the extremity joints, such as the knee and shoulder. There will sometimes also be a cavitation in the extremity joints when you receive an adjustment.