title: Influence of repetitive transcranial magnetic stimulation on tibialis anterior activity during walking in humans.
abstract: OBJECTIVE
  To determine whether or not modulation of the excitability of the M1 region controlling the lower limb (using repetitive transcranial magnetic stimulation; TMS) would change the TA's activity during gait and the effect of aging on this change.
  
  
  METHODS
  In three separate sessions, participants underwent different repetitive TMS (rTMS) protocols (sham stimulation, intermittent theta-burst stimulation (TBS) and continuous TBS) delivered over the M1 region controlling the lower limb muscles, using a focal, figure-of-eight coil. Before and after rTMS, the TA's activity was recorded using surface electrodes while participants walked at a freely chosen speed and at an imposed speed on a treadmill. Cortical excitability was assessed by characterizing input-output (IO) curves, after fitting the relationship between motor evoked potential amplitude and stimulus intensity with a Boltzmann sigmoidal equation.
  
  
  RESULTS
  We did not observe any effects of rTMS in terms of TA activation during locomotion, gait parameters or IO curves in either healthy young adults or elderly adults. Elderly patients presented lower excitability of cortical TA representation area.
  
  
  CONCLUSIONS
  Modulation of TA activity by TBS was ineffective contrary to what is observed for upper limbs. Interindividual variability in the effects of rTMS on TA activation, activation of the TA before the rTMS and/or differences in the depth of the cortical representation of the TA could have influenced the results and should be taken into account for further studies.
authors.affiliation: Centre Hospitalier Régional Universitaire de Lille, Département d'analyse du mouvement, F-59037 Lille Cedex, France. Electronic address: melanie.rambour86@gmail.com.
authors.forename: Mélanie
authors.initials: M
authors.lastname: Rambour
authors.affiliation: Université du Littoral Côte d'Opale, Université de Lille, EA 7369-URePSSS, rue Ferdinand Buisson, F-62228 Calais Cedex, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Caux-Dedeystère
authors.affiliation: Centre Hospitalier Régional Universitaire de Lille, Département d'analyse du mouvement, F-59037 Lille Cedex, France; Université du Littoral Côte d'Opale, Université de Lille, EA 7369-URePSSS, rue Ferdinand Buisson, F-62228 Calais Cedex, France.
authors.forename: Hervé
authors.initials: H
authors.lastname: Devanne
authors.affiliation: Centre Hospitalier Régional Universitaire de Lille, Département d'analyse du mouvement, F-59037 Lille Cedex, France; Université de Lille, Inserm U1171-Troubles cognitifs dégénératifs et vasculaires, F-59000 Lille, France.
authors.forename: Luc
authors.initials: L
authors.lastname: Defebvre
authors.affiliation: Centre Hospitalier Régional Universitaire de Lille, Département d'analyse du mouvement, F-59037 Lille Cedex, France; Université de Lille, Inserm U1171-Troubles cognitifs dégénératifs et vasculaires, F-59000 Lille, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Derambure
authors.affiliation: Centre Hospitalier Régional Universitaire de Lille, Département d'analyse du mouvement, F-59037 Lille Cedex, France; Université de Lille, Inserm U1171-Troubles cognitifs dégénératifs et vasculaires, F-59000 Lille, France.
authors.forename: Arnaud
authors.initials: A
authors.lastname: Delval
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D005684:Gait; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D016138:Walking; D055815:Young Adult
keywords: Gait; Primary motor cortex; Repetitive transcranial magnetic stimulation; Tibialis anterior