title: Analysis on the activation of the VMO and VLL muscles during semisquat exercises with and without hip adduction in individuals with patellofemoral pain syndrome.
abstract: OBJECTIVE
  The purpose of this study was to investigate the effect of hip adduction on the activity of the Vastus Medialis Obliquus (VMO) and Vastus Lateralis Longus (VLL) muscles during semisquat exercises.
  
  
  METHODS
  Twenty female subjects, divided into two groups comprising healthy and patellofemoral pain syndrome (PFPS) subjects (ten volunteers for each group), performed three double-leg semisquat exercise trials with maximum hip adduction isometric contraction (DLSS-HA) and three double-leg semisquat exercise trials without hip adduction (DLSS). The normalized electromyographic muscle data were analysed using Repeated Measure ANOVA (p<or=0.05).
  
  
  RESULTS
  The electrical activity of both VMO and VLL muscles was significantly greater during DLSS-HA exercise than during DLSS (p=0.0002) for both groups. Additionally, an independent Repeated Measure ANOVA revealed that the electric activity of the VLL muscle was significantly greater (p=0.0149) than that of the VMO muscle during DLSS exercises only for the PFPS group. However, no differences were found during DLSS-HA exercises.
  
  
  CONCLUSIONS
  Although there was no preferential VMO muscle activation, the association of hip adduction with squat exercise promoted a greater balance between the medial and lateral portions of the quadriceps femoris muscle and could be indicated for the conservatory treatment of PFPS patients. The association of isometric hip adduction with isometric semisquat exercises produced a more overall quadriceps activity and could be indicated for clinical rehabilitation or muscle strengthening programs.
authors.affiliation: Federal University of São Carlos, Rodovia Washington Luís, Km 235, São Carlos-SP 13565-905, Brazil.
authors.forename: Kelly Rafael Ribeiro
authors.initials: KR
authors.lastname: Coqueiro
authors.forename: Débora
authors.initials: D
authors.lastname: Bevilaqua-Grossi
authors.forename: Fausto
authors.initials: F
authors.lastname: Bérzin
authors.forename: Alcimar Barbosa
authors.initials: AB
authors.lastname: Soares
authors.forename: Cecília
authors.initials: C
authors.lastname: Candolo
authors.forename: Vanessa
authors.initials: V
authors.lastname: Monteiro-Pedro
mesh_terms: D000328:Adult; D004576:Electromyography; D015444:Exercise; D005080:Exercise Test / Q000379:methods; D005081:Exercise Therapy / Q000379:methods; D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D008297:Male; D009119:Muscle Contraction; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology* / Q000628:therapy; D004856:Postural Balance; D011187:Posture; D052097:Quadriceps Muscle / Q000503:physiopathology*