title: Immediate increases in quadriceps corticomotor excitability during an electromyography biofeedback intervention.
abstract: The purpose of the study was to determine the effects of EMG-BF on vastus lateralis corticomotor excitability, measured via motor evoked potential (MEP) amplitudes elicited using Transcranial Magnetic Stimulation (TMS) during a maximal voluntary isometric contraction (MVIC). We also determined the effect of EMG-BF on isometric knee extensor strength. Fifteen healthy participants volunteered for this crossover study with two sessions held one-week apart. Participants were randomly assigned to condition order, during which five intervention MVICs were performed with or without EMG-BF. MEP amplitudes were collected with TMS during five knee extension contractions (5% of MVIC) at baseline and again during intervention MVICs within each session. During the control condition, participants were instructed to perform the same number of MVICs without any EMG-BF. Percent change scores were used to calculate the change in peak-to-peak MEP amplitudes that occurred during EMG-BF and Control MVICs compared to the baseline MEPs. Peak knee extension torque was recorded during MVICs prior to TMS for each condition. EMG-BF produced significantly increased MEP change scores and significantly greater torque than the control condition. The results of the current study suggest that EMG-BF may be a viable clinical method for targeting corticomotor excitability.
authors.affiliation: Department of Exercise and Sports Science, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States. Electronic address: brian@unc.edu.
authors.forename: Brian
authors.initials: B
authors.lastname: Pietrosimone
authors.affiliation: Department of Health and Human Performance, College of Charleston, Charleston, SC, United States.
authors.forename: Michelle M
authors.initials: MM
authors.lastname: McLeod
authors.affiliation: Department of Athletics, United States Naval Academy, Annapolis, MD, United States.
authors.forename: David
authors.initials: D
authors.lastname: Florea
authors.affiliation: College of Health Sciences, University of Kentucky, Lexington, KY, United States.
authors.forename: Phillip A
authors.initials: PA
authors.lastname: Gribble
authors.affiliation: Department of Rehabilitation Sciences, University of Toledo, Toledo, OH, United States.
authors.forename: Michael A
authors.initials: MA
authors.lastname: Tevald
mesh_terms: D000293:Adolescent; D001676:Biofeedback, Psychology / Q000379:methods / Q000502:physiology*; D018592:Cross-Over Studies; D004576:Electromyography / Q000379:methods*; D019054:Evoked Potentials, Motor / Q000502:physiology; D005260:Female; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007719:Knee Joint / Q000502:physiology; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D052097:Quadriceps Muscle / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods; D055815:Young Adult
keywords: Arthrogenic muscle inhibition; Knee; Rehabilitation