Logan College of Chiropractic/University Programs graduate Arlan Fuhr, DC, and the late W.C. Lee, DC, developed Activator Methods. Initially, the doctors used thumb thrusts, delivered at rapid rates of speed generated by elbow movement. They developed the Activator instrument to avoid injuries to doctors, resulting from the thumb thrusts, and to ensure consistency from one adjustment to the next. The instrument is patented and was approved in 1984 by the U.S. Food and Drug Administration, for use in adjustive procedures.
The spring-loaded instrument is used with a specific line of drive and can be set to deliver force ranging from nine to 33 pounds per square inch. Before an adjustment is administered, leg length checks and isolation tests of joint motion are performed to identify joints to be adjusted, and these tests can be used to check adjustment effectiveness afterwards. Activator Methods adjustments also can be used on extremity joints.
Activator Methods Lead Instructor