title: Proportional lumbar spine inter-vertebral motion patterns: a comparison of patients with chronic, non-specific low back pain and healthy controls.
abstract: BACKGROUND
  Identifying biomechanical subgroups in chronic, non-specific low back pain (CNSLBP) populations from inter-vertebral displacements has proven elusive. Quantitative fluoroscopy (QF) has excellent repeatability and provides continuous standardised inter-vertebral kinematic data from fluoroscopic sequences allowing assessment of mid-range motion. The aim of this study was to determine whether proportional continuous IV rotational patterns were different in patients and controls. A secondary aim was to update the repeatability of QF measurement of range of motion (RoM) for inter-vertebral (IV) rotation.
  
  
  METHODS
  Fluoroscopic sequences were recorded of passive, recumbent coronal and sagittal motion, which was controlled for range and velocity. Segments L2-5 in 40 primary care CNSLBP patients and 40 matched controls were compared. Patients also completed the von Korff Chronic Pain Grade and Roland and Morris Disability Questionnaire. Sequences were processed using automated image tracking algorithms to extract continuous inter-vertebral rotation data. These were converted to continuous proportional ranges of rotation (PR). The continuous proportional range variances were calculated for each direction and combined to produce a single variable representing their fluctuation (CPRV). Inter- and intra-rater repeatability were also calculated for the maximum IV-RoM measurements obtained during controlled trunk motion to provide an updated indication of the reliability and agreement of QF for measuring spine kinematics.
  
  
  RESULTS
  CPRV was significantly higher in patients (0.011 vs. 0.008, Mann-Whitney two-sided p = 0.008), implying a mechanical subgroup. Receiver operating characteristic curve analysis found its sensitivity and specificity to be 0.78 % (60-90) and 0.55 % (37-73), respectively (area under the curve 0.672). CPRV was not correlated with pain severity or disability. The repeatability of maximum inter-vertebral range was excellent, but range was only significantly greater in patients at L4-5 in right side bending (p = 0.03).
  
  
  CONCLUSIONS
  The variation in proportional motion between lumbar vertebrae during passive recumbent trunk motion was greater in patients with CNSLBP than in matched healthy controls, indicating that biomechanical factors in passive structures play a part.
authors.affiliation: Institute for Musculoskeletal Research and Clinical Implementation, Anglo-European College of Chiropractic, Parkwood Road, Bournemouth, BH5 2DF, UK.
authors.forename: Fiona E
authors.initials: FE
authors.lastname: Mellor
authors.forename: Peter W
authors.initials: PW
authors.lastname: Thomas
authors.forename: Paul
authors.initials: P
authors.lastname: Thompson
authors.forename: Alan C
authors.initials: AC
authors.lastname: Breen
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D059350:Chronic Pain / Q000000981:diagnostic imaging / Q000503:physiopathology; D003430:Cross-Sectional Studies; D005260:Female; D005471:Fluoroscopy / Q000379:methods* / Q000592:standards; D006801:Humans; D017116:Low Back Pain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D011187:Posture / Q000502:physiology; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D012399:Rotation; D012680:Sensitivity and Specificity; D055815:Young Adult