title: Reliability of the functional measures of the corticospinal pathways to dorsiflexor muscles during maximal voluntary contractions.
abstract: This study aimed to evaluate the intra- and inter-day reliability of transcranial magnetic stimulation (TMS)-related measurements recorded from the tibialis anterior (TA) muscle. Thirteen healthy young men and women (23±4years) performed 3 testing sessions to assess intra- (i.e., two sessions performed the same day) and inter-day (i.e. two sessions performed one week apart) reliability of (i) dorsiflexion cortical maximal voluntary activation level (VATMS), (ii) TA corticospinal excitability assessed through the amplitude of the motor evoked potentials (MEP) recorded during 100, 75 and 50% maximal voluntary contractions (MVC), and (iii) intracortical inhibition investigated via the cortical silent period (CSP) recorded at the same % MVC. Absolute (i.e., coefficient of variation (CV) and standard error of the mean (SEM)), and relative (i.e., intraclass correlation coefficients (ICC)) reliability parameters were calculated. VATMS demonstrated excellent intra- and inter-day reliabilities (ICC: 0.80 and 0.99; CV: 1.7 and 0.8%, respectively). MEPs and CSPs presented moderate to excellent intra- and inter-day reliabilities, while input-output curves extracted parameters presented highly variable outcomes. These results suggest that most TA corticospinal measurements during voluntary contractions can be used to quantify corticospinal adaptations after acute (e.g. fatigue) or long term (e.g. training) interventions.
authors.affiliation: Univ Lyon, UJM-Saint-Etienne, LIBM, F-42023 Saint-Etienne, France.
authors.forename: Robin
authors.initials: R
authors.lastname: Souron
authors.affiliation: Univ Lyon, UJM-Saint-Etienne, LIBM, F-42023 Saint-Etienne, France.
authors.forename: Adrien
authors.initials: A
authors.lastname: Farabet
authors.affiliation: Human Performance Laboratory, Faculty of Kinesiology, University of Calgary, Canada.
authors.forename: Guillaume Y
authors.initials: GY
authors.lastname: Millet
authors.affiliation: Univ Lyon, UJM-Saint-Etienne, LIBM, F-42023 Saint-Etienne, France. Electronic address: thomas.lapole@univ-st-etienne.fr.
authors.forename: Thomas
authors.initials: T
authors.lastname: Lapole
mesh_terms: D000328:Adult; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D007266:Inhibition, Psychological; D008297:Male; D009119:Muscle Contraction / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology*; D010543:Peroneal Nerve / Q000502:physiology; D011712:Pyramidal Tracts / Q000502:physiology*; D015203:Reproducibility of Results; D019415:Torque; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: Boltzmann modelling; Cortical voluntary activation; Corticospinal excitability; Tibialis anterior; Transcranial magnetic stimulation