title: Does inter-vertebral range of motion increase after spinal manipulation? A prospective cohort study.
abstract: BACKGROUND
  Spinal manipulation for nonspecific neck pain is thought to work in part by improving inter-vertebral range of motion (IV-RoM), but it is difficult to measure this or determine whether it is related to clinical outcomes.
  
  
  OBJECTIVE
  This study undertook to determine whether cervical spine flexion and extension IV-RoM increases after a course of spinal manipulation, to explore relationships between any IV-RoM increases and clinical outcomes and to compare palpation with objective measurement in the detection of hypo-mobile segments.
  
  
  METHODS
  Thirty patients with nonspecific neck pain and 30 healthy controls matched for age and gender received quantitative fluoroscopy (QF) screenings to measure flexion and extension IV-RoM (C1-C6) at baseline and 4-week follow-up between September 2012-13. Patients received up to 12 neck manipulations and completed NRS, NDI and Euroqol 5D-5L at baseline, plus PGIC and satisfaction questionnaires at follow-up. IV-RoM accuracy, repeatability and hypo-mobility cut-offs were determined. Minimal detectable changes (MDC) over 4 weeks were calculated from controls. Patients and control IV-RoMs were compared at baseline as well as changes in patients over 4 weeks. Correlations between outcomes and the number of manipulations received and the agreement (Kappa) between palpated and QF-detected of hypo-mobile segments were calculated.
  
  
  RESULTS
  QF had high accuracy (worst RMS error 0.5o) and repeatability (highest SEM 1.1o, lowest ICC 0.90) for IV-RoM measurement. Hypo-mobility cut offs ranged from 0.8o to 3.5o. No outcome was significantly correlated with increased IV-RoM above MDC and there was no significant difference between the number of hypo-mobile segments in patients and controls at baseline or significant increases in IV-RoMs in patients. However, there was a modest and significant correlation between the number of manipulations received and the number of levels and directions whose IV-RoM increased beyond MDC (Rho=0.39, p=0.043). There was also no agreement between palpation and QF in identifying hypo-mobile segments (Kappa 0.04-0.06).
  
  
  CONCLUSIONS
  This study found no differences in cervical sagittal IV-RoM between patients with non-specific neck pain and matched controls. There was a modest dose-response relationship between the number of manipulations given and number of levels increasing IV-RoM - providing evidence that neck manipulation has a mechanical effect at segmental levels. However, patient-reported outcomes were not related to this.
authors.affiliation: Institute of Musculoskeletal Research & Clinical Implementation, Anglo-European College of Chiropractic, 13-15 Parkwood Road, Bournemouth BH5 2DF, UK ; The School of Health & Social Care, Bournemouth University, Royal London House, Christchurch Road, Bournemouth BH1 3LT, UK.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Branney
authors.affiliation: Institute of Musculoskeletal Research & Clinical Implementation, Anglo-European College of Chiropractic, 13-15 Parkwood Road, Bournemouth BH5 2DF, UK.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Breen
keywords: Fluoroscopy; Manipulation; Neck pain; Patient-reported outcomes; Spine kinematics