title: Single-Leg Squat as a Tool to Evaluate Young Athletes' Frontal Plane Knee Control.
abstract: OBJECTIVE
  To determine the agreement between 2-dimensional video analysis and subjective visual assessment by a physiotherapist in evaluating young athletes' knee control, and to determine the intrarater reliability and inter-rater reliability of the single-leg squat test.
  
  
  METHODS
  Frontal plane knee control was assessed by a physiotherapist on a 3-point scale. Frontal plane projection angles were calculated from video images. To determine the intrarater reliability, a physiotherapist reassessed 60 subjects' performances from a video. For the inter-rater reliability, 20 subjects were assessed by both the physiotherapist and a nonexperienced tester. The study continued for 3 test years.
  
  
  METHODS
  Research institute.
  
  
  METHODS
  Three hundred and seventy-eight floorball, basketball, ice hockey, and volleyball players.
  Knee control was assessed to be good, reduced, or poor.
  
  
  METHODS
  Agreement between the video analysis and subjectively assessed frontal plane knee control. Intrarater reliability and inter-rater reliability.
  
  
  RESULTS
  There were statistically significant differences in the mean frontal plane knee angles between subjects rated as having "good," "reduced," or "poor" knee control. Intrarater reliability was fair for the assessments in the first year, moderate (dominant leg) and good (nondominant leg) for the second year, and very good (dominant leg) and good (nondominant leg) for the third year. Inter-rater reliability was fair/poor.
  
  
  CONCLUSIONS
  This study suggests that by using the subjective assessment of the single-leg squat task, it is possible to detect differences in frontal plane knee control in young team sport athletes. The assessment can be considered to be reliable for clinical use when performed by an experienced tester.
authors.affiliation: *Tampere Research Center of Sports Medicine, UKK Institute for Health Promotion Research, Tampere, Finland; †Department of Sports Sciences, Oslo Sports Trauma Research Center, Norwegian School of Sports Sciences, Oslo, Norway; ‡NeuroMuscular Research Center, Department of Biology of Physical Activity, University of Jyväskylä, Jyväskylä, Finland; and §Tampere University of Applied Sciences, Tampere, Finland.
authors.forename: Anu
authors.initials: A
authors.lastname: Räisänen
authors.forename: Kati
authors.initials: K
authors.lastname: Pasanen
authors.forename: Tron
authors.initials: T
authors.lastname: Krosshaug
authors.forename: Janne
authors.initials: J
authors.lastname: Avela
authors.forename: Jarmo
authors.initials: J
authors.lastname: Perttunen
authors.forename: Jari
authors.initials: J
authors.lastname: Parkkari
mesh_terms: D000293:Adolescent; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D010808:Physical Examination / Q000379:methods*; D011446:Prospective Studies; D014741:Video Recording; D055815:Young Adult