title: Absolute and relative reliability of isokinetic and isometric trunk strength testing using the IsoMed-2000 dynamometer.
abstract: OBJECTIVE
  The present study aimed to assess the between day reliability of isokinetic and isometric peak torque (PT) during trunk measurement on an isokinetic device (IsoMed 2000).
  
  
  METHODS
  Test-retest-protocol on five separate days.
  
  
  METHODS
  Fifteen healthy sport students (8 female and 7 male) aged 21 to 26.
  
  
  METHODS
  PT was assessed in isometric back extension and flexion as well as right and left rotation. Isokinetic strength was captured at a speed of 60°/s and 150°/s for all tasks.
  
  
  RESULTS
  For none of the assessed parameters a meaningful variation in PT during test days was observed. Relative reliability (ICC = 0.85-0.96) was excellent for all tasks. Estimates of absolute reliability as Coefficient of Variation (CoV) and Standard Error of Measurement (SEM in Nm/kg lean body mass) remained stable for isometric (6.9% < CoV < 9.4%; 0.15 < SEM < 0.23) and isokinetic mode (60°/s: 3.7% < CoV < 8.6%; 0.08 < SEM < 0.24; 150°/s: 6.9% < CoV < 12.4%; 0.10 < SEM < 0.31). In contrast, reliability between familiarization day and day 1 was lower (6.6% < CoV < 26.2%; 0.10 < SEM < 0.65).
  
  
  CONCLUSIONS
  Trunk strength measurement in flexion and extension or trunk rotation in either isometric or isokinetic condition is highly reliable. Therefore, it seems possible to elucidate changes which are smaller than 10% due to intervention programs when a preceding familiarization condition was applied.
authors.affiliation: Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320B, 4052, Basel, Switzerland. Electronic address: ralf.roth@unibas.ch.
authors.forename: Ralf
authors.initials: R
authors.lastname: Roth
authors.affiliation: Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320B, 4052, Basel, Switzerland. Electronic address: lars.donath@unibas.ch.
authors.forename: Lars
authors.initials: L
authors.lastname: Donath
authors.affiliation: Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320B, 4052, Basel, Switzerland; Clinic for Trauma, Hand and Reconstructive Surgery, Division of Motor Research, Pathophysiology and Biomechanics, Jena University Hospital, Bachstrasse 18, 07743, Jena, Germany. Electronic address: eduard.kurz@med.uni-jena.de.
authors.forename: Eduard
authors.initials: E
authors.lastname: Kurz
authors.affiliation: Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320B, 4052, Basel, Switzerland. Electronic address: lukas.zahner@unibas.ch.
authors.forename: Lukas
authors.initials: L
authors.lastname: Zahner
authors.affiliation: Department of Sport, Exercise and Health, University of Basel, Birsstrasse 320B, 4052, Basel, Switzerland. Electronic address: oliver.faude@unibas.ch.
authors.forename: Oliver
authors.initials: O
authors.lastname: Faude
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D008297:Male; D009119:Muscle Contraction / Q000502:physiology; D053580:Muscle Strength / Q000502:physiology*; D053581:Muscle Strength Dynamometer; D018482:Muscle, Skeletal / Q000502:physiology*; D015203:Reproducibility of Results; D013909:Thorax / Q000502:physiology*; D019415:Torque
keywords: Assessment; Extension/Flexion; Peak Torque; Rotation