title: Classification of lower extremity movement patterns based on visual assessment: reliability and correlation with 2-dimensional video analysis.
abstract: BACKGROUND
  Abnormal movement patterns have been implicated in lower extremity injury. Reliable, valid, and easily implemented assessment methods are needed to examine existing musculoskeletal disorders and investigate predictive factors for lower extremity injury.
  
  
  OBJECTIVE
  To determine the reliability of experienced and novice testers in making visual assessments of lower extremity movement patterns and to characterize the construct validity of the visual assessments.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  University athletic department and research laboratory.
  
  
  METHODS
  Convenience sample of 30 undergraduate and graduate students who regularly participate in athletics (age = 19.3 ± 4.5 years). Testers were 2 experienced physical therapists and 1 novice postdoctoral fellow (nonclinician).
  
  
  METHODS
  We took videos of 30 athletes performing the single-legged squat. Three testers observed the videos on 2 occasions and classified the lower extremity movement as dynamic valgus, no change, or dynamic varus. The classification was based on the estimated change in frontal-plane projection angle (FPPA) of the knee from single-legged stance to maximum single-legged squat depth. The actual FPPA change was measured quantitatively. We used percentage agreement and weighted κ to examine tester reliability and to determine construct validity of the visual assessment.
  
  
  RESULTS
  The κ values for intratester and intertester reliability ranged from 0.75 to 0.90, indicating substantial to excellent reliability. Percentage agreement between the visual assessment and the quantitative FPPA change category was 90%, with a κ value of 0.85.
  
  
  CONCLUSIONS
  Visual assessments were made reliably by experienced and novice testers. Additionally, movement-pattern categories based on visual assessments were in excellent agreement with objective methods to measure FPPA change. Therefore, visual assessments can be used in the clinic to assess movement patterns associated with musculoskeletal disorders and in large epidemiologic studies to assess the association between lower extremity movement patterns and musculoskeletal injury.
authors: Program in Physical Therapy, Washington University School of Medicine, St Louis, MO.
authors: Marcie
authors: M
authors: Harris-Hayes
authors: Karen
authors: K
authors: Steger-May
authors: Christine
authors: C
authors: Koh
authors: Nat K
authors: NK
authors: Royer
authors: Valentina
authors: V
authors: Graci
authors: Gretchen B
authors: GB
authors: Salsich
mesh_terms: D000328:Adult; D001837:Body Weights and Measures / Q000592:standards*; D015331:Cohort Studies; D003430:Cross-Sectional Studies; D005260:Female; D064368:Healthy Volunteers; D006615:Hip / Q000502:physiology; D006801:Humans; D007717:Knee / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D008297:Male; D009068:Movement / Q000502:physiology*; D053580:Muscle Strength / Q000502:physiology; D011446:Prospective Studies; D016059:Range of Motion, Articular / Q000502:physiology; D015203:Reproducibility of Results; D013177:Sports / Q000502:physiology*; D014741:Video Recording / Q000379:methods*; D055815:Young Adult
keywords: athletic injuries; knee valgus; movement analysis; screening