title: A magnetic resonance imaging investigation of the transversus abdominis muscle during drawing-in of the abdominal wall in elite Australian Football League players with and without low back pain.
abstract: METHODS
  Single-blinded quasi-experimental study.
  
  
  OBJECTIVE
  To investigate the ability of elite football players with and without low back pain (LBP) to voluntarily draw-in the abdominal wall.
  
  
  BACKGROUND
  While there has been considerable debate regarding the contribution of the transversus abdominis (TrA) muscle to control the lumbar spine and pelvis, there is evidence that retraining motor control of the deep trunk muscles is commensurate with decreases in LBP. Magnetic resonance imaging (MRI) has been used to assess the TrA muscle during the draw-in maneuver, with the contraction of the TrA muscle reducing the circumference of the trunk. Impairments in performance of the draw-in maneuver have been shown in people with LBP.
  
  
  METHODS
  Forty-three elite players from a team in the Australian Football League were allocated to 3 groups: those with "no LBP," "a history of LBP but no current LBP," or "current LBP." MRI was used to image the cross-sectional area (CSA) of the trunk at the level of the L3-4 disc at the start and end of the draw-in maneuver.
  
  
  RESULTS
  There was a significant decrease in the CSA of the trunk with the performance of the draw-in maneuver (P<.001). Subjects in the "no LBP" group were better able to "draw-in" the abdominal wall than subjects with current LBP (P = .015).
  
  
  CONCLUSIONS
  This study provides evidence of an altered ability to draw-in the abdominal wall in footballers with current LBP. Retraining contraction of the TrA muscle may constitute one part of an exercise-therapy approach for athletes with current LBP.
authors.affiliation: Division of Physiotherapy, School of Health and Rehabilitation Sciences, University of Queensland, Brisbane, Australia. j.hides1@uq.edu.au
authors.forename: Julie A
authors.initials: JA
authors.lastname: Hides
authors.forename: Carly L
authors.initials: CL
authors.lastname: Boughen
authors.forename: Warren R
authors.initials: WR
authors.lastname: Stanton
authors.forename: Mark W
authors.initials: MW
authors.lastname: Strudwick
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Wilson
mesh_terms: D000009:Abdominal Muscles / Q000033:anatomy & histology / Q000502:physiology* / Q000503:physiopathology; D000293:Adolescent; D000328:Adult; D056352:Athletes; D016022:Case-Control Studies; D005081:Exercise Therapy; D005538:Football; D006801:Humans; D017116:Low Back Pain / Q000503:physiopathology* / Q000628:therapy; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction; D016037:Single-Blind Method; D055815:Young Adult