People familiar with chiropractic care likely have experienced the popping noise of chiropractic adjustments. This may feel and sound like a clicking of the spine during treatment. A doctor of chiropractic presses on your neck or back and, click, something happened. Later when someone asks you what happened at the doctor, you respond, “my neck popped,” or “my back clicked.” But what is actually happening? Where does the sound come from?
What actually causes the popping noise of chiropractic adjustments?
The objective of a spinal manipulation (aka chiropractic adjustment) is to increase motion of specific joints in a specific direction. Every joint in our body has a designed amount of motion in a certain direction for healthy functioning of that joint and the joints around it. When a specific joint or group of joints are restricted in their motion from swelling, scarring, joint capsule tightness, or surrounding muscle tension, the normal spinal mechanics are altered. Like links in a chain, if one becomes stuck, the adjacent joints move more than their design allows. The resulting imbalance of joint motion causes joint swelling, muscle tension, and eventually, pain.
The solution, therefore, is to treat the joint imbalance. When one has a tight muscle, it needs to be stretched, and a series of stretching improves the length of the muscle. When one has a restricted joint, it needs to be adjusted, and a series of adjustments gives improved motion to the joint.
The popping noise of chiropractic adjustments is a simple side effect of the treatment. The inside of most joints are at a negative pressure with fluid holding the joint surfaces together. (This phenomenon is modeled by water between two panes of glass; the plates slide easily but cannot be pulled apart.) A chiropractic adjustment causes the joint to gap, pulling gas from the solution (like a bubble forming in soda). You can make a similar sound by clicking your tongue on the roof of your mouth. After the click of the adjustments it takes about 20-30 minutes for the joint fluid to reach equilibrium again. It cannot click during this time.
Not every type of chiropractic adjustment causes a popping noise. Your doctor of chiropractic may choose from a variety of adjustment techniques, so do not assume that the lack of a popping noise indicates an incomplete treatment. Every chiropractic adjustment technique intends to improve the balance of movement across the spine and other joints.