title: The relationship between the piriformis muscle, low back pain, lower limb injuries and motor control training among elite football players.
abstract: OBJECTIVE
  Australian Football League (AFL) players have a high incidence of back injuries. Motor control training to increase lumbopelvic neuromuscular control has been effective in reducing low back pain (LBP) and lower limb injuries in elite athletes. Control of pelvic and femoral alignment during functional activity involves the piriformis muscle. This study investigated (a) the effect of motor control training on piriformis muscle size in AFL players, with and without LBP, during the playing season, and (b) whether there is a relationship between lower limb injury and piriformis muscle size.
  
  
  METHODS
  Stepped-wedge intervention.
  
  
  METHODS
  46 AFL players participated in a motor control training programme consisting of two 30min sessions per week over 7-8 weeks, delivered across the season as a randomised 3 group single-blinded stepped-wedge design. Assessment of piriformis muscle cross-sectional area (CSA) involved magnetic resonance imaging (MRI) at 3 time points during the season. Assessment of LBP consisted of player interview and physical examination. Injury data were obtained from club records.
  
  
  RESULTS
  An interaction effect for Time, Intervention Group and LBP group (F=3.7, p=0.03) was found. Piriformis muscle CSA showed significant increases between Times 1 and 2 (F=4.24, p=0.046), and Times 2 and 3 (F=8.59, p=0.006). Players with a smaller increase in piriformis muscle CSA across the season had higher odds of sustaining an injury (OR=1.08).
  
  
  CONCLUSIONS
  Piriformis muscle size increases across the season in elite AFL players and is affected by the presence of LBP and lower limb injury. Motor control training positively affects piriformis muscle size in players with LBP.
authors.affiliation: School of Physiotherapy, Australian Catholic University, Brisbane Campus (McAuley at Banyo), Australia; The University of Queensland, School of Health and Rehabilitation Sciences, Division of Physiotherapy, Australia. Electronic address: felix.leung@acu.edu.au.
authors.forename: Felix T
authors.initials: FT
authors.lastname: Leung
authors.affiliation: School of Physiotherapy, Australian Catholic University, Brisbane Campus (McAuley at Banyo), Australia.
authors.forename: M Dilani
authors.initials: MD
authors.lastname: Mendis
authors.affiliation: School of Physiotherapy, Australian Catholic University, Brisbane Campus (McAuley at Banyo), Australia.
authors.forename: Warren R
authors.initials: WR
authors.lastname: Stanton
authors.affiliation: School of Physiotherapy, Australian Catholic University, Brisbane Campus (McAuley at Banyo), Australia; Mater/ACU Back Stability Clinic, Mater Health Services, Australia.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Hides
mesh_terms: D000328:Adult; D001315:Australia; D025461:Feedback, Physiological; D005538:Football / Q000293:injuries* / Q000502:physiology; D006801:Humans; D017116:Low Back Pain / Q000150:complications; D035002:Lower Extremity / Q000293:injuries*; D008279:Magnetic Resonance Imaging; D008297:Male; D009119:Muscle Contraction; D009126:Muscle Relaxation; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology; D009929:Organ Size; D064797:Physical Conditioning, Human / Q000502:physiology*; D016037:Single-Blind Method; D013997:Time Factors; D055815:Young Adult
keywords: Australian Football League; Lower limb injury; Magnetic resonance imaging; Motor control training; Piriformis