title: Skin accelerometer displacement and relative bone movement of adjacent vertebrae in response to chiropractic percussion thrusts.
abstract: The authors studied relative bone movements in response to manipulative light taps to the spine. Piezoelectric accelerometers attached to bone of an anesthetized dog measured transverse, X-Z plane, movements of L2-L3 adjacent vertebrae while percussion thrusts of an instrument used for manipulation made inputs three vertebrae above and five vertebrae below the L2-L3 joint interface. Small, relative 1-mm translations and 0.5 degree rotations occurred during the first 19 msec. When one set of accelerometers were stabilized on the skin surface, half of the skin-bone translation maxima erred less than 2%. However, skin translations averaged 77% (SD = 2%) of bone translations and skin rotations averaged 95% (SD = 26%) of bone rotations. The results suggest the possibility that, with further development, piezoelectric accelerometers can be a noninvasive tool to study dynamic, relative, bone movement.
authors.affiliation: Activator Methods, Inc., Phoenix, Arizona 85060-0317.
authors.forename: D B
authors.initials: DB
authors.lastname: Smith
authors.forename: A W
authors.initials: AW
authors.lastname: Fuhr
authors.forename: B P
authors.initials: BP
authors.lastname: Davis
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D002684:Chiropractic / Q000379:methods*; D004285:Dogs; D008159:Lumbar Vertebrae / Q000502:physiology*; D009068:Movement; D010474:Percussion / Q000379:methods*; D012879:Skin Physiological Phenomena