Why Doesn't the Activator Make My Bones Crack?

If you've ever been to a manual chiropractor (that is, a chiropractor who uses his or her hands to make the adjustment), you've no doubt experienced "the pop". The pop is the audible noise that occurs when the adjustment is delivered. Many patients grow to love the pop, since they associate the sound with the relief they feel after the adjustment.

If you've ever been to Johnson Family Chiropractic, you know that we deliver our adjustments with the Activator instrument. Since the Activator adjustment produces no associated popping noise (called a "cavitation"), some patients initially think that the adjustment didn't happen. After all, the adjustment must occur when the popping sound is heard, right?

Not according to research. Many journal articles have been written which maintain that the sound of the pop and the delivery of the adjustment are two separate and distinct things. The most recent in a long line of articles in the renowned Journal of Manipulative and Physiological Therapeutics states that "the presence of joint sounds does not influence the overall activity of the autonomic nervous system following a joint manipulation or contribute to the reduction of pain in patients with chronic neck pain."

In that study, the researchers were producing the joint popping sound without actually delivering an adjustment. And they found that without the adjustment, there was no nervous system input, which meant that the patient felt no relief and was not healing.

The joint popping sound is really nothing more than a simple physics experiment. Almost every joint in the body is encased in a small ligamentous sac filled with fluid, called "synovial fluid". The fluid bathes the cartilage in the joint, delivers nutrients to the cartilage cells, and cushions the joint. When the joint is suddenly moved by a shear force (parallel to the direction of the joint) to the limit of its movement capability, a small bubble of gas is fomed inside the fluid and instantaneously popped. (There's another current theory that holds that the cavitation noise is actually the sudden release of a vacuum created inside the joint).

You can "pop" your own joints. Many people do (although it's not recommended for several reasons, which I'll address in a future blog post). However, a pop isn't the same thing as an adjustment. This is good news for many people who actively dislike hearing noises coming from their joints.

The Activator doesn't cause a pop because a pop only occurs when the joint is stressed or pulled as far as it can physiologically go. The researchers behind the Activator instrument realized that far less force is necessary to move the bone than was first thought. Since the Activator thrust doesn't move the bone "too far", no pop is produced, even the adjustment was successfully delivered.

This reduction of force is what allows Johnson Family Chiropractic adjustments to be gentle yet effective. The Activator instrument does not make your bones pop, but it does produce an exceptional and repeatable adjustment.