title: The effects of movement pattern modification on lower extremity kinematics and pain in women with patellofemoral pain.
abstract: METHODS
  Controlled laboratory study.
  
  
  OBJECTIVE
  To compare hip and knee kinematics and pain during a single-limb squat between 3 movement conditions (usual, exaggerated dynamic knee valgus, corrected dynamic knee valgus) in women with patellofemoral pain.
  
  
  BACKGROUND
  Altered kinematics (increased hip adduction, hip medial rotation, knee abduction, and knee lateral rotation, collectively termed dynamic knee valgus) have been proposed to contribute to patellofemoral pain; however, cross-sectional study designs prevent interpreting a causal link between kinematics and pain.
  
  
  METHODS
  The study sample included 20 women with patellofemoral pain, who demonstrated observable dynamic knee valgus. Participants performed single-limb squats under usual, exaggerated, and corrected movement conditions. Pain during each condition was assessed using a 0-to-100-mm visual analog scale. Hip and knee frontal and transverse plane angles at peak knee flexion and pain levels were compared using repeated-measures 1-way analyses of variance. Pearson correlation coefficients were used to determine within-condition associations between kinematic variables and pain.
  
  
  RESULTS
  In the exaggerated compared to the usual condition, increases were detected in hip medial rotation (mean ± SD difference, 5.8° ± 3.2°; P<.001), knee lateral rotation (5.5° ± 4.9°, P<.001), and pain (8.5 ± 10.8 mm, P = .007). In the corrected compared to the usual condition, decreases were detected in hip adduction (mean ± SD difference, 3.5° ± 3.7°; P = .001) and knee lateral rotation (1.6° ± 2.8°, P = .06); however, average pain was not decreased (1.2 ± 14.8 mm, P = 1.0). Pain was correlated with knee lateral rotation in the usual (r = -0.47, P = .04) and exaggerated (r = -0.49, P = .03) conditions. In the corrected condition, pain was correlated with hip medial rotation (r = 0.44, P = .05) and knee adduction (r = 0.52, P = .02).
  
  
  CONCLUSIONS
  Avoiding dynamic knee valgus may be an important component of rehabilitation programs in women with patellofemoral pain, as this movement pattern is associated with increased pain.
authors.affiliation: Program in Physical Therapy, Saint Louis University, 3437 Caroline Street, St Louis, MO 63104, USA. salsichg@slu.edu
authors.forename: Gretchen B
authors.initials: GB
authors.lastname: Salsich
authors.forename: Valentina
authors.initials: V
authors.lastname: Graci
authors.forename: Dwayne E
authors.initials: DE
authors.lastname: Maxam
mesh_terms: D000293:Adolescent; D000328:Adult; D001696:Biomechanical Phenomena; D005260:Female; D006621:Hip Joint / Q000503:physiopathology*; D006801:Humans; D057071:Patellofemoral Joint / Q000503:physiopathology*; D046788:Patellofemoral Pain Syndrome / Q000503:physiopathology*; D055815:Young Adult