title: Muscular activity of patella and hip stabilizers of healthy subjects during squat exercises.
abstract: BACKGROUND
  Hip and knee muscle weaknesses have been associated with the onset of anterior knee pain (AKP). Therefore, the understanding of how squats exercises can be performed in order to optimize the electrical activity of these muscles is relevant for physical therapy treatments.
  
  
  OBJECTIVE
  To compare the electromyographic activity of patella and pelvic stabilizers during traditional squat and squat associated with isometric hip adduction or abduction in subjects without AKP.
  
  
  METHODS
  Electromyography signals were captured using double-differential electrodes at the vastus medialis obliquus (VMO), vastus lateralis obliquus (VLO), vastus lateralis longus (VLL) and gluteus medium (GMed) in 15 healthy and sedentary women during squats exercises: traditional and associated with hip adduction and hip abduction with load of 25% of body weight. Linear mixed models with significance level of 5% were used for data analysis.
  
  
  RESULTS
  Squat associated with hip adduction and abduction produced electromyographic activity of GMed of 0.47 (0.2) and 0.59 (0.22) respectively, while conventional squat produced an electromyiographic activity of 0.33 (0.27). The higher VMO activity was 0.59 (0.27) during the isometric contraction in the squat associated with hip adduction. The higher VLO activity was 0.60 (0.32) during isometric contraction in the squat associated with hip abduction.
  
  
  CONCLUSIONS
  Squat exercise associated with hip adduction increased VMO muscle activity as well as the activity of GMed activity.
authors.affiliation: Postgraduate Program of Health Science Applied of Locomotor Apparatus, School of Medicine from Ribeirão Preto (FMRP), Universidade de São Paulo (USP), Ribeirão Preto, SP, Brazil. lilianrf@uol.com.br
authors.forename: Lilian R
authors.initials: LR
authors.lastname: Felício
authors.forename: Luiza A
authors.initials: LA
authors.lastname: Dias
authors.forename: Ana P M C
authors.initials: AP
authors.lastname: Silva
authors.forename: Anamaria S
authors.initials: AS
authors.lastname: Oliveira
authors.forename: Débora
authors.initials: D
authors.lastname: Bevilaqua-Grossi
mesh_terms: D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006615:Hip / Q000502:physiology*; D006801:Humans; D018482:Muscle, Skeletal / Q000502:physiology*; D010329:Patella / Q000502:physiology*; D012016:Reference Values; D055815:Young Adult