title: No difference in gluteus medius activation in women with mild patellofemoral pain.
abstract: BACKGROUND
  The gluteus medius (Gmed) is proposed to consist of 3 functional subdivisions (anterior, middle, and posterior). Gmed weakness and dysfunction have been implicated in numerous lower extremity disorders, including patellofemoral pain syndrome (PFPS). PFPS is a knee condition that frequently occurs in females and is associated with activities such as squatting and stair climbing. There is a lack of evidence for the role of the subdivisions of the Gmed in females with and without PFPS.
  
  
  OBJECTIVE
  To compare muscle activation in the 3 Gmed subdivisions during 4 weight-bearing exercises in women with and without PFPS.
  
  
  METHODS
  Single-session, repeated-measures observational study.
  
  
  METHODS
  University research laboratory.
  
  
  METHODS
  Convenience sample of 12 women with PFPS and 12 age- and gender-matched asymptomatic controls.
  
  
  METHODS
  Participants performed 4 weight-bearing exercises (wall press, pelvic drop, step-up-and-over, and unilateral squat) 3 times while surface electromyography (sEMG) activity of the Gmed segments was recorded.
  
  
  METHODS
  sEMG muscle activity for each functional subdivision of the Gmed during each weight-bearing exercise was analyzed using a mixed between-within-subjects ANOVA (post hoc Bonferroni).
  
  
  RESULTS
  No statistically significant differences in muscle activation were found between the PFPS and healthy participants (P = .97). Furthermore, there were no statistically significant differences between the exercises (P = .19) or muscle fibers (P = .36) independent of group analyzed. However, the activation of the subdivisions varied according to the exercise performed (P = .003).
  
  
  CONCLUSIONS
  Similar levels of muscle activation were recorded in the Gmed subdivisions of the PFPS and healthy participants during the different exercises. This is the first study to examine all 3 Gmed subdivisions in PFPS. Future studies using larger sample sizes should also investigate onset and duration of muscle activation in all Gmed subdivisions in both healthy individuals and those with PFPS.
authors: Physiotherapy Dept, University of Limerick, Limerick, Ireland.
authors: Kieran
authors: K
authors: O'Sullivan
authors: Ellen
authors: E
authors: Herbert
authors: David
authors: D
authors: Sainsbury
authors: Karen
authors: K
authors: McCreesh
authors: Amanda
authors: A
authors: Clifford
mesh_terms: D000328:Adult; D002081:Buttocks; D004576:Electromyography; D005080:Exercise Test; D005260:Female; D006615:Hip / Q000502:physiology; D006801:Humans; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D016474:Weight-Bearing / Q000502:physiology; D055815:Young Adult