title: Distribution of cavitations as identified with accelerometry during lumbar spinal manipulation.
abstract: OBJECTIVE
  This project determined the location and distribution of cavitations (producing vibrations and audible sounds) in the lumbar zygapophyseal (Z) joints that were targeted by spinal manipulative therapy (SMT).
  
  
  METHODS
  This randomized, controlled, clinical study assessed 40 healthy subjects (20 men, 20 women) 18 to 30 years of age who were block randomized into SMT (group 1, n = 30) or side-posture positioning only (group 2; control, n = 10) groups. Nine accelerometers were placed on each patient (7 on spinous processes/sacral tubercles of L1-S2 and 2 placed 3 cm left and right lateral to the L4/L5 interspinous space). Accelerometer recordings were made during side-posture positioning (groups 1 and 2) and SMT (group 1 only). The SMT was delivered by a chiropractic physician with 19 years of practice experience and included 2 high-velocity, low-amplitude thrusts delivered in rapid succession. Comparisons using χ(2) or McNemar test were made between number of joints cavitating from group 1 vs group 2, upside (contact side for SMT) vs downside, and Z joints within the target area (L3/L4, L4L5, L5/S1) vs outside the target area (L1/L2, L2/L3, sacroiliac).
  
  
  RESULTS
  Fifty-six cavitations were recorded from 46 joints of 40 subjects. Eight joints cavitated more than once. Group 1 joints cavitated more than group 2 joints (P < .0001), upside joints cavitated more than downside joints (P < .0001), and joints inside the target area cavitated more than those outside the target area (P < .01).
  
  
  CONCLUSIONS
  Most cavitations (93.5%) occurred on the upside of SMT subjects in segments within the target area (71.7%). As expected, SMT subjects cavitated more frequently than did subjects with side-posture positioning only (96.7% vs 30%). Multiple cavitations from the same Z joints had not been previously reported.
authors: Dean of Research, Department of Research, National University of Health Sciences, Lombard, IL, USA. gcramer@nuhs.edu
authors: Gregory D
authors: GD
authors: Cramer
authors: J Kim
authors: JK
authors: Ross
authors: P K
authors: PK
authors: Raju
authors: Jerrilyn A
authors: JA
authors: Cambron
authors: Jennifer M
authors: JM
authors: Dexheimer
authors: Preetam
authors: P
authors: Bora
authors: Ray
authors: R
authors: McKinnis
authors: Scott
authors: S
authors: Selby
authors: Adam R
authors: AR
authors: Habeck
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008297:Male; D020393:Manipulation, Spinal; D013016:Sound; D014732:Vibration; D055815:Young Adult