title: Gluteal muscle function and size in swimmers.
abstract: OBJECTIVE
  To compare the gluteus medius and minimus segments size and activity in swimmers versus non-swimmers.
  
  
  METHODS
  Case matched-control cross-sectional study.
  
  
  METHODS
  The three segments of gluteus medius (anterior, middle and posterior) and two segments of gluteus minimus (anterior and posterior) were evaluated using electromyography and magnetic resonance imaging in 15 swimmers (7 elite and 8 non-elite) and 15 gender- and aged-matched controls. For each muscle segment, values were obtained for peak amplitude, average amplitude, and time to peak from each phase of the gait cycle (0-20%, 20-60%, and total stance).
  
  
  RESULTS
  The pattern of anterior gluteus minimus EMG activity in swimmers demonstrated additional activity early in the gait cycle when compared with controls. The segmental differences between anterior and posterior gluteus minimus during gait identified in the control group were not present in the swimmers. Overall, there were no significant differences in the gluteus medius EMG characteristics between groups and muscle size was not significantly different between groups for any of the hip abductor muscles.
  
  
  CONCLUSIONS
  The preliminary evidence of non-segmental differences within the gluteus minimus of swimmers (as opposed to non-swimmers) might implicate reduced-gravity environments in contributing to subsequent changes in deep stabiliser muscles. Such changes might predispose the athlete to a greater risk of lower limb injury during weight bearing activities.
authors.affiliation: School of Health and Rehabilitation Sciences, The University of Queensland, Australia; Sport, Exercise and Rehabilitation Research Focus Area, La Trobe University, Australia. Electronic address: adam.semciw@gmail.com.
authors.forename: Adam I
authors.initials: AI
authors.lastname: Semciw
authors.affiliation: Sport, Exercise and Rehabilitation Research Focus Area, La Trobe University, Australia; Department of Pharmacy and Applied Sciences, La Trobe University, Australia.
authors.forename: Rodney A
authors.initials: RA
authors.lastname: Green
authors.affiliation: Sport, Exercise and Rehabilitation Research Focus Area, La Trobe University, Australia; School of Allied Health, College of Science, Health and Engineering, La Trobe University, Australia.
authors.forename: Tania
authors.initials: T
authors.lastname: Pizzari
mesh_terms: D000704:Analysis of Variance; D056352:Athletes; D002081:Buttocks; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004576:Electromyography; D005260:Female; D005684:Gait / Q000502:physiology; D006615:Hip / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D018482:Muscle, Skeletal / Q000033:anatomy & histology* / Q000502:physiology*; D013550:Swimming / Q000502:physiology*; D055815:Young Adult
keywords: Buttocks; Gait; Gluteus medius; Gluteus minimus; Hip; Swimming