To provide an historical overview, description, synthesis, and critique of the Activator Adjusting Instrument (AAI) and Activator Methods Chiropractic Technique of clinical assessment.


Online resources were searched including Index to Chiropractic Literature, EBSCO Online, MANTIS, CHIROLARS, CINAHL, eJournals, Ovid, MDConsult, Lane Catalog, SU Catalog, and Pubmed. Relevant peer-reviewed studies, commentaries, and reviews were selected. Studies fell into 2 major content areas: instrument adjusting and the analysis system for therapy application. Studies were categorized by research content type: biomechanical, neurophysiological, and clinical. Each study was reviewed in terms of contribution to knowledge and critiqued with regard to quality.


More than 100 studies related to the AAI and the technique were found, including studies on the instrument’s mechanical effects, and a few studies on clinical efficacy. With regard to the analysis, there is evidence for good reliability on prone leg-length assessment, but to date, there is only 1 study evaluating the Activator Methods Chiropractic Technique analysis.


A body of basic science and clinical research has been generated on the AAI since its first peer-reviewed publication in 1986. The Activator analysis may be a clinically useful tool, but its ultimate scientific validation requires testing using sophisticated research models in the areas of neurophysiology, biomechanics, and statistical analysis.

J Manipulative Physiol Ther. 2005 Feb;28(2):e1-e20. [PMID:15800504]

Author information: Fuhr AW, Menke JM. Activator Methods International, Ltd, Phoenix, AZ, USA.

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