title: The reliability of portable fixed dynamometry during hip and knee strength assessments.
abstract: BACKGROUND
  Insufficient lower extremity strength may be a risk factor for lower extremity injuries such as noncontact anterior cruciate ligament tears. Therefore, clinicians need reliable instruments to assess strength deficiencies.
  
  
  OBJECTIVE
  To assess the intrarater, interrater, intrasession, and intersession reliability of a portable fixed dynamometer in measuring the strength of the hip and knee musculature.
  
  
  METHODS
  Crossover study.
  
  
  METHODS
  Sports medicine research laboratory.
  
  
  METHODS
  Three raters (A, B, C) participated in this 2-phase study. Raters A and B tested 11 healthy college graduate students (2 men, 9 women) in phase 1. Raters A and C tested 26 healthy college undergraduate students (7 men, 19 women) in phase 2.
  
  
  METHODS
  The dependent variables for the study were hip adductor, hip abductor, hip flexor, hip extensor, hip internal rotator, hip external rotator, knee flexor, and knee extensor peak force.
  
  
  RESULTS
  The phase 1 intrasession intraclass correlation coefficients for sessions 1, 2, and 3 ranged from 0.88 to 0.99 (SEM = 0.08-3.02 N), 0.85 to 0.99 (SEM = 0.26-3.88 N), and 0.92 to 0.96 (SEM = 0.52-2.76 N), respectively. Intraclass correlation coefficients ranged from 0.57 to 0.95 (SEM = 1.72-13.15 N) for phase 1 intersession values, 0.70 to 0.94 (SEM = 1.42-9.20 N) for phase 2 intrarater reliability values, and 0.69 to 0.88 (SEM = 1.20-8.50 N) for phase 2 interrater values.
  
  
  CONCLUSIONS
  The portable fixed dynamometer showed good to high intrasession and intersession reliability values for hip and knee strength. Intrarater and interrater reliability were fair to high, except for hip internal rotation, which showed poor reliability.
authors.affiliation: Old Dominion University, Norfolk, VA, USA.
authors.forename: Roger O
authors.initials: RO
authors.lastname: Kollock
authors.forename: James A
authors.initials: JA
authors.lastname: Onate
authors.forename: Bonnie
authors.initials: B
authors.lastname: Van Lunen
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D005260:Female; D006304:Health Status; D006621:Hip Joint / Q000502:physiology*; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D015203:Reproducibility of Results; D012307:Risk Factors; D013223:Statistics as Topic; D055815:Young Adult