title: Test-retest reliability of the Biodex System 4 Isokinetic Dynamometer for knee strength assessment in paediatric populations.
abstract: BACKGROUND
  Isokinetic dynamometry is a widely used tool for measuring muscle strength in clinical intervention and rehabilitation as well as research in children.
  
  
  OBJECTIVE
  To assess the test-retest reliability of knee flexor/extensor strength using the Biodex Multi-Joint System 4 Isokinetic Dynamometer in children.
  
  
  METHODS
  Peak isometric knee extensor (KE) and peak isokinetic knee flexor (KF) torques of the dominant and nondominant limbs were assessed twice in 11 children aged 10 to 13 yrs, 7 to 10 days apart.
  
  
  RESULTS
  Peak torques were higher in the dominant limb (p ≤ 0.006). Peak isometric KE torque was 8.4% higher (SEM 2.5%) at the second testing session, but there was no interaction with the limb tested (p > 0.2). Peak isokinetic KE/KF torque ratios agreed well between tests and had intraclass correlation coefficients (ICCs) of 0.96.
  
  
  CONCLUSIONS
  The dynamometer provides a reliable means of assessing knee strength in 10 to 13 year olds, with excellent test-retest reliability for isokinetic KE/KF. A learning effect occurred when assessing isometric torque, indicating the importance of habituation for this measure.
authors.affiliation: Nutritional Physiology Research Centre, School of Health Sciences, University of South Australia, Adelaide, SA, Australia.
authors.forename: Margarita D
authors.initials: MD
authors.lastname: Tsiros
authors.forename: Paul N
authors.initials: PN
authors.lastname: Grimshaw
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Schield
authors.forename: Jonathan D
authors.initials: JD
authors.lastname: Buckley
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D015203:Reproducibility of Results; D019415:Torque