The Activator Method Chiropractic Technique is a chiropractic treatment method and device created by Arlan Fuhr as an alternative to manual manipulation of the spine or extremity joints. The device is categorized as a mechanical force manual assisted (MFMA) instrument which is generally regarded as a softer chiropractic treatment technique.
The activator is a small handheld spring-loaded instrument which delivers a small impulse to the spine. It was found to give off no more than 0.3 J of kinetic energy in a 3-millisecond pulse. The goal of this method and use of the activator is to produce enough force to move the vertebrae but not enough to cause injury.
When used for chiropractic, the Activator Method involves having the patient lie in a prone position and comparing the functional leg lengths. Often one leg will seem to be slightly shorter than the other. Next, the chiropractor carries out a series of muscle tests such as having the patient move their arms in a certain position in order to activate the muscles attached to specific vertebrae. If the leg lengths change, that is taken as a sign that the problem is located at that vertebra. The chiropractor treats these problems moving progressively along the spine in the direction from the feet towards the head.