Activator Methods Chiropractic Technique: General Articles
Activator Methods: An Update and Review (Part One of Two)
Malik Slosberg, D.C.; Activator Methods Chiropractic Technique: General Articles; Chiropractic Economics
In the more than 20 years of its evolution, the Activator Methods chiropractic technique has developed both instrumentation and analysis to produce a clinically safe, non-traumatic, and systematic method of evaluation and treatment of manipulable joint lesions. We will review some of the distinctive characteristics of the technique In order to increase chiropractors' understanding and appreciation for this exceptional method of chiropractic care.
The Activator adjusting Instrument Is a hand-held adjusting device designed to generate reproducible and controlled force, displacement, acceleration, and specific line of correction. The Activator attempts to eliminate the enormous variability inherent In manual adjusting. Ranges of force used in manual adjusting have been reported to be from 1.5 lbs. to 125 lbs. by Wood and Adams" and from 30 lbs. to 130 lbs. by Duell., Such wide ranges will certainly affect the paraspinal structures In different ways and make evaluation of the effects of adjustment difficult to assess. Clinically, such wide ranges of force also make It difficult to provide consistency of care from doctor to doctor or, perhaps, even by the same doctor at different times of the day, or from day to day.
Studies by Fuhr and Smith and Duell have evaluated the characteristics of the Activator adjusting instrument and the thrust it generates and have reported that it produces a consistent and reliable controlled force (from 3 to 28 lbs., depending on the setting of the adjustment knob)" displacement (0.80 mm per revolution of the expansion control knob)o and acceleration (1.79 m/sec in 2 msec) within narrow ranges of variability. Furthermore, the duration of the Activator thrust, which is between 0.002 to 0.004 second, Is approximately 15 to 40 times faster than the meric thrust produced by chiropractors skilled In that technique' and 100 to 200 times faster than the manual Thompson type of thrust.' The duration of the thrust generated by the Activator Instrument has also been calibrated to be 5-10 times shorter than the stretch reflex, which takes 19- 24 msec for the quadriceps In man.' Fuhr and Smith state that there was a latency of 17.5 msec between impact stimulation by the Instrument's thrust and the EMG response when fired into the biceps tendon of a human. These data Indicate that the stretch reflex of the intrinsic muscles of the spine may be unable to oppose the impact of the force produced by the Activator and therefore cannot resist its effect on contacted articulations. The inability for muscles to contract before the Activator thrust is completed reduces the functional tissue resistance, and therefore there is less inertia to overcome in order to initiate movement into a motion segment.
The Activator adjusting instrument is a hand-held adjusting device designed to generate reproducible and controlled force, displacement, acceleration, and specific line of correction.