title: Relationship between frontal plane projection angle of the knee and hip and trunk strength in women with and without patellofemoral pain.
abstract: BACKGROUND
  It is theorized that increased dynamic knee valgus relates to decreased hip posterolateral muscle strength.
  
  
  OBJECTIVE
  The aim here was to assess the relationship between the frontal plane projection angle (FPPA) of the knee and hip and trunk muscle strength in women with and without patellofemoral pain (PFP).
  
  
  METHODS
  The sample comprised 43 women: Patellofemoral Pain Group (PPG, n = 22) and Control Group (CG, n = 21). Muscle strength for hip abduction, extension, external rotation and lateral core were measured using a handheld dynamometer. The FPPA was recorded during step-down.
  
  
  RESULTS
  The PPG showed a deficit for hip muscles torque and increased FPPA (P < 0.05). Negative correlation of the FPPA-Peak was found in the CG for the hip abductor (r = -0.31) and posterolateral complex (r = -0.32) (P < 0.05). In the PPG, the FPPA-Peak showed a moderate negative correlation to the torque of external rotators and posterolateral hip muscles, although this correlation did not reach statistical significance.
  
  
  CONCLUSIONS
  These findings suggest that women with patellofemoral pain present greater dynamic knee valgus and hip muscle weakness. Abductor and posterolateral hip muscles strength are associated with increased FPPA only in the pain-free population.
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.|Physical Therapy Department, Federal University of Ceará, Fortaleza, Brazil.
authors.forename: Gabriel Peixoto Leão
authors.initials: GP
authors.lastname: Almeida
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Ana Paula de Moura Campos Carvalho E
authors.initials: AP
authors.lastname: Silva
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Fábio Jorge Renovato
authors.initials: FJ
authors.lastname: França
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Maurício Oliveira
authors.initials: MO
authors.lastname: Magalhães
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Thomaz Nogueira
authors.initials: TN
authors.lastname: Burke
authors.affiliation: Physical Therapy, Speech and Occupational Therapy Department, School of Medicine, University of São Paulo, São Paulo, Brazil.
authors.forename: Amélia Pasqual
authors.initials: AP
authors.lastname: Marques
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena / Q000502:physiology; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D008875:Middle Aged; D053580:Muscle Strength / Q000502:physiology*; D018908:Muscle Weakness / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000503:physiopathology*; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D012399:Rotation; D019415:Torque; D060726:Torso / Q000503:physiopathology; D055815:Young Adult
keywords: Patellofemoral joint; biomechanics; kinematic; knee injuries; muscle strength dynamometer