"Subluxation" has been defined medically as "...a partial abnormal separation of the articular surfaces of a joint."Chiropractors have described the term to include a complex of functions (i.e., the subluxation complex) as "...an alteration of the biomechanical and physiological dynamics of contiguous structures which can cause neural disturbances."

Learn more at http://www.spine-health.com/treatment/chiropractic/subluxation-and-chiropractic