title: The audible pop is not necessary for successful spinal high-velocity thrust manipulation in individuals with low back pain.
abstract: OBJECTIVE
  To determine the relationship between an audible pop and symptomatic improvement with spinal manipulation in patients with low back pain (LBP).
  
  
  METHODS
  A prospective cohort study.
  
  
  METHODS
  Two outpatient physical therapy clinics located in military medical centers.
  
  
  METHODS
  A cohort of 71 patients with nonradicular LBP referred to physical therapy.
  
  
  METHODS
  Participants underwent a standardized examination and standardized spinal manipulation treatment program. All patients were treated with a sacroiliac (SI) region manipulative technique and the presence or absence of an audible pop was noted.
  
  
  METHODS
  Subjects were reassessed 48 hours after the manipulation for changes in range of motion (ROM), numeric pain rating scale (PRS) scores, and modified Oswestry Disability Questionnaire (ODQ) scores.
  
  
  RESULTS
  An audible pop occurred in 50 of the 71 subjects during the manipulative procedure. Both groups-those who had an audible pop and those who did not-improved over time in flexion ROM, PRS scores, and modified ODQ scores; however, there were no differences between groups (P>.05). Nineteen of the 71 (27%) patients improved dramatically (mean drop in modified ODQ, 67.6%). In 14 of the 19 dramatic responders, an audible pop occurred. However, the odds ratio (1.2; 95% confidence interval, 0.38-4.04) suggested that the occurrence of a manipulative pop would not improve the odds of achieving a dramatic reduction in symptoms after the manipulation.
  
  
  CONCLUSIONS
  There is no relationship between an audible pop during SI region manipulation and improvement in ROM, pain, or disability in individuals with nonradicular LBP. Additionally, the occurrence of a pop did not improve the odds of a dramatic improvement with manipulation treatment.
authors.affiliation: US Army-Baylor University Graduate Program in Physical Therapy, San Houston, Texas, 78234-6138, USA. timothy.flynn@cen.amedd.army.mil
authors.forename: Timothy W
authors.initials: TW
authors.lastname: Flynn
authors.forename: Julie M
authors.initials: JM
authors.lastname: Fritz
authors.forename: Robert S
authors.initials: RS
authors.lastname: Wainner
authors.forename: Julie M
authors.initials: JM
authors.lastname: Whitman
mesh_terms: D000293:Adolescent; D000328:Adult; D001291:Attitude of Health Personnel; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis / Q000503:physiopathology / Q000628:therapy*; D008297:Male; D020393:Manipulation, Spinal / Q000379:methods*; D008875:Middle Aged; D010147:Pain Measurement; D011446:Prospective Studies; D016059:Range of Motion, Articular; D013016:Sound; D011795:Surveys and Questionnaires; D013997:Time Factors; D016896:Treatment Outcome