The physics behind a chiropractic adjustment is a well studied and discussed topic. Newton’s Laws of Motion specifically, help to explain the powerful results one can experience from a chiropractic adjustment.

Newton’s 1st Law of Motion in Chiropractic

Newton’s First Law of Motion states that an object at rest will remain at rest unless a force acts upon it. This explains the premise and importance of the chiropractic adjustment. If a joint in your neck or your back is not moving and therefore “at rest,” it will require a specific force to get it moving again. In order to prevent certain conditions, such as arthritis, it is important that all the joints in your body move properly.

The most well-known and most widely-used chiropractic adjustment techniques incorporate High-Velocity, Low-Amplitude (HVLA) thrusts to achieve the adjustment. HVLA is often used in Diversified, Thompson Drop, and Gonstead chiropractic techniques.

If you have ever visited a chiropractor for an adjustment and you heard your neck or back “crack” you experienced what is known as an audible cavitation. An audible cavitation is most often a result of a HVLA adjustment.

Newton’s 2nd Law of Motion in Chiropractic

In order to understand the HVLA adjustment, we need to take a closer look at Newton’s Second Law of Motion (Force = Mass X Acceleration).

We can use this equation to help understand how to create enough force to perform a chiropractic adjustment. The amount of force required to adjust a joint is equal to the size (Mass) of the contacted area multiplied by the speed needed to do so (Acceleration.) The Force of an adjustment will be greater if it is concentrated over a smaller area of the body.

Another way we can use Newton’s Second Law of motion to understand HVLA adjustments is by looking at the size (Mass) of the chiropractor performing the adjustment. With certain HVLA adjustments, the smaller the chiropractor is, the faster they need to be to create the same amount of Force as a larger chiropractor. In other words, to create a specific amount of Force, a chiropractor who weighs 100 pounds needs to be faster when they perform certain adjustments than a chiropractor who weighs 200 pounds.

What Patients Should Know About the Physics Behind An Adjustment

The internet is flooded with information about how physics applies to the chiropractic adjustment. For a chiropractic patient, the two most important points to keep in mind is:

1. According to Newton’s First Law of Motion, if a joint in your body is not moving properly, it will not start to move properly unless a specific force is acted upon it to get it moving again. In other words, if your joints are not moving properly, receiving a chiropractic adjustment will help to restore the proper movement of those joints.

2. According to Newton’s Second Law of Motion, the physical size of your chiropractor does play a roll in the way they adjust. If you see a chiropractor like Dr. Shelly Seidenberg who weighs just over 100 pounds, each adjustment you receive may feel quicker than if you see a chiropractor who weighs 200 pounds. However, as long as the correct amount of Force is properly applied and the correct technique is used, you will get excellent results from your adjustment.

If you’d like to schedule an appointment with Dr. Shelly Seidenberg, please request an appointment online or call (386) 307-8207.


Natural Health Practices is Volusia County’s holistic health haven offering safe, natural, and effective solutions to many health problems. ​The team at Natural Health Practices believes in the body’s miraculous ability to heal without the use of drugs or surgeries.