title: Evaluation of peak force of a manually operated chiropractic adjusting instrument with an adapter for use in animals.
abstract: OBJECTIVE
  This study was designed to assess the peak force of a manually operated chiropractic adjusting instrument, the Activator Adjusting Instrument 4 (AAI 4), with an adapter for use in animals, which has a 3- to 4-fold smaller contact surface area than the original rubber tip.
  
  
  METHODS
  Peak force was determined by thrusting the AAI 4 with the adapter or the original rubber tip onto a load cell. First, the AAI 4 was applied perpendicularly by a doctor of chiropractic onto the load cell. Then, the AAI 4 was fixed in a rigid framework and applied to the load cell. This procedure was done to prevent any load on the load cell before the thrust impulse. In 2 situations, trials were performed with the AAI 4 at all force settings (settings I, II, III, and IV, minimum to maximum, respectively). A total of 50000 samples per second over a period of 3 seconds were collected.
  
  
  RESULTS
  In 2 experimental protocols, the use of the adapter in the AAI 4 increased the peak force only with setting I. The new value was around 80% of the maximum value found for the AAI 4. Nevertheless, the peak force values of the AAI 4 with the adapter and with the original rubber tip in setting IV were similar.
  
  
  CONCLUSIONS
  The adapter effectively determines the maximum peak force value at force setting I of AAI 4.
authors.affiliation: Academic Researcher, Department of Physiology, Institute of Basic Health Science, Federal University of Rio Grande do Sul/UFRGS, Porto Alegre, Brazil. Electronic address: felipe.quiropraxia@gmail.com.
authors.forename: Felipe Coutinho Kullmann
authors.initials: FC
authors.lastname: Duarte
authors.affiliation: Academic Researcher, Department of Physiology, Institute of Basic Health Science, Federal University of Rio Grande do Sul/UFRGS, Porto Alegre, Brazil.
authors.forename: Carolina
authors.initials: C
authors.lastname: Kolberg
authors.affiliation: Technician, Department of Mechanical Engineering, School of Engineering, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Rodrigo R
authors.initials: RR
authors.lastname: Barros
authors.affiliation: Private Practice, Porto Alegre, Brazil.
authors.forename: Vivian G A
authors.initials: VG
authors.lastname: Silva
authors.affiliation: Professor, Chiropractic Graduation Program from Feevale University, Novo Hamburgo, Brazil.
authors.forename: Günter
authors.initials: G
authors.lastname: Gehlen
authors.affiliation: Professor and Academic Researcher, Department of Mechanical Engineering, School of Engineering, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Jakson M
authors.initials: JM
authors.lastname: Vassoler
authors.affiliation: Professor and Academic Researcher, Department of Physiology, Institute of Basic Health Science, Federal University of Rio Grande do Sul/UFRGS, Porto Alegre, Brazil.
authors.forename: Wania A
authors.initials: WA
authors.lastname: Partata
mesh_terms: D000818:Animals; D004867:Equipment Design; D006801:Humans; D026882:Manipulation, Chiropractic / Q000295:instrumentation*; D055595:Mechanical Phenomena
keywords: Biomechanics; Chiropractic; Manipulation, Spinal