title: Gluteus medius activation during running is a risk factor for season hamstring injuries in elite footballers.
abstract: OBJECTIVE
  To investigate if size and activation of the gluteal muscles is a risk factor for hamstring injuries in elite AFL players.
  
  
  METHODS
  Prospective cohort study.
  
  
  METHODS
  Twenty-six elite male footballers from a professional Australian Football League (AFL) club participated in the study. At the beginning of the season bilateral gluteus medius (GMED) and gluteus maximus (GMAX) muscle volume was measured from magnetic resonance images and electromyographic recordings of the same muscles were obtained during running. History of hamstring injury in the pre-season and incidence of hamstring injury during the season were determined from club medical data.
  
  
  RESULTS
  Nine players (35%) incurred a hamstring injury during the season. History of hamstring injury was comparable between those players who incurred a season hamstring injury (2/9 players; 22%) and those who did not (3/17 players; 18%). Higher GMED muscle activity during running was a risk factor for hamstring injury (p=0.03, effect sizes 1.1-1.5). There were no statistically significant differences observed for GMED volume, GMAX volume and GMAX activation (P>0.05).
  
  
  CONCLUSIONS
  This study identified higher activation of the GMED muscle during running in players who sustained a season hamstring injury. Whilst further research is required to understand the mechanism of altered muscle control, the results of this study contribute to the developing body of evidence that the lumbo-pelvic muscles may be important to consider in hamstring injury prevention and management.
authors.affiliation: Centre for Musculoskeletal Research, Mary MacKillop Institute for Health Research, Australian Catholic University, Australia. Electronic address: melinda.smith@acu.edu.au.
authors.forename: Melinda M
authors.initials: MM
authors.lastname: Franettovich Smith
authors.affiliation: Centre for Sports Research, School of Exercise and Nutrition Sciences, Deakin University, Australia.
authors.forename: Jason
authors.initials: J
authors.lastname: Bonacci
authors.affiliation: Centre for Musculoskeletal Research, Mary MacKillop Institute for Health Research, Australian Catholic University, Australia; Physiotherapy Department, Mater Health Services, Australia.
authors.forename: M Dilani
authors.initials: MD
authors.lastname: Mendis
authors.affiliation: Carlton Football Club, Australia.
authors.forename: Craig
authors.initials: C
authors.lastname: Christie
authors.affiliation: Victoria House Medical Imaging, Australia.
authors.forename: Andrew
authors.initials: A
authors.lastname: Rotstein
authors.affiliation: Centre for Musculoskeletal Research, Mary MacKillop Institute for Health Research, Australian Catholic University, Australia; Mater/ACU Back Stability Research Clinic, Mater Health Services, Australia.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Hides
mesh_terms: D000328:Adult; D001315:Australia; D002081:Buttocks; D005538:Football / Q000293:injuries*; D006801:Humans; D007869:Leg Injuries / Q000209:etiology*; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000293:injuries / Q000502:physiology*; D011446:Prospective Studies; D012307:Risk Factors; D012420:Running / Q000293:injuries*; D013848:Thigh / Q000293:injuries
keywords: Electromyography; Gait; Magnetic resonance imaging; Prospective studies