title: Segmental mobility of the lumbar spine during a posterior to anterior mobilization: assessment using dynamic MRI.
abstract: OBJECTIVE
  To quantify segmental mobility of the lumbar spine during a posterior to anterior spinal mobilization procedure.
  
  
  METHODS
  Descriptive study using dynamic magnetic resonance imaging.
  
  
  BACKGROUND
  The posterior to anterior spinal mobilization procedure is frequently used in the assessment and management of spinal dysfunction. How this procedure influences segmental spinal motion however, is not known.
  
  
  METHODS
  Eleven asymptomatic subjects were positioned prone within a vertically open double donut design magnetic resonance imaging system. An anteriorly directed force was applied manually at each lumbar spinous process while magnetic resonance images were obtained continuously in the sagittal plane. The intervertebral angle was used to quantify segmental motion.
  
  
  RESULTS
  The direction of motion at the tested segment was always extension, with values ranging from 1.2 (SD 2.2) at L2 to 3.0 (SD 2.3) degrees at L5. When the force was applied at L3, L4 and L5, the non-tested (adjacent) segments also were observed to move into extension. However, when the posterior to anterior force was applied at L1 and L2 the three caudal segments moved into flexion.
  
  
  CONCLUSIONS
  Posterior to anterior spinal mobilization consistently caused extension at the tested segment, while the motion of the collective lumbar spine was either an increase or decrease in lordosis depending on the segment at which the force was applied.
  
  
  CONCLUSIONS
  Passive movement techniques are commonly used to identify the symptomatic lumbar segment(s) and can be used as a treatment aimed at increasing mobility and/or decreasing pain. Knowledge of how this procedure influences segmental motion of healthy spines is important in understanding how altered mobility is related to symptoms.
authors.affiliation: Department of Biokinesiology and Physical Therapy, University of Southern California, 1540 East Alcazar St., CHP-155, Los Angeles, CA 90033, USA. powers@usc.edu
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Powers
authors.forename: Kornelia
authors.initials: K
authors.lastname: Kulig
authors.forename: James
authors.initials: J
authors.lastname: Harrison
authors.forename: Gabrielle
authors.initials: G
authors.lastname: Bergman
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000033:anatomy & histology* / Q000502:physiology*; D008161:Lumbosacral Region / Q000033:anatomy & histology / Q000502:physiology; D019028:Magnetic Resonance Imaging, Cine / Q000379:methods*; D008297:Male; D020393:Manipulation, Spinal / Q000379:methods*; D008875:Middle Aged; D009038:Motion; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013131:Spine / Q000033:anatomy & histology / Q000502:physiology; D013314:Stress, Mechanical