title: Intersession reliability of the interpolated twitch technique applied during isometric, concentric, and eccentric actions of the human knee extensor muscles.
abstract: Although it has been shown that voluntary activation (%VA) of the knee extensors during isometric contractions can be reliably assessed with the interpolated twitch technique, little is known about the reliability of %VA during concentric and eccentric muscle actions. Therefore, relative and absolute intersession reliability of quadriceps muscle's %VA during different contraction modes was determined.
  
  
  
  After a familiarization session, 21 participants (17 males, 25 ± 2 yrs) completed two testing sessions. Paired supramaximal electrical stimuli were administered to the femoral nerve during isometric, concentric, eccentric MVCs, and at rest to assess %VA (stimuli were applied at 70° knee flexion).
  
  
  
  Data indicate that %VA of the knee extensors can be reliably measured during isometric [intraclass correlation coefficient (ICC) = 0.89, coefficient of variation (CV) = 4.1%], concentric (ICC = 0.87, CV = 6.6%), and eccentric muscle actions (ICC = 0.86, CV = 7.0%). Muscle Nerve 56: 324-327, 2017.
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Behrens
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Florian
authors.initials: F
authors.lastname: Husmann
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Gube
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Felser
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Weippert
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Sven
authors.initials: S
authors.lastname: Bruhn
authors.affiliation: Institute of Sport Science, University of Rostock, Ulmenstraße 69, 18057, Rostock, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Zschorlich
authors.affiliation: Department of Orthopaedics, University Medicine Rostock, Doberaner Straße 142, 18057, Rostock, Germany.
authors.forename: Anett
authors.initials: A
authors.lastname: Mau-Moeller
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology*; D007717:Knee / Q000294:innervation*; D008297:Male; D052097:Quadriceps Muscle / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult
keywords: electrical stimulation; femoral nerve; paired electrical stimuli; quadriceps femoris muscle; twitch; voluntary activation