title: Phase-dependent modulation of corticospinal excitability during the observation of the initial phase of gait.
abstract: This study was undertaken to identify the temporal characteristics of corticospinal excitability of tibialis anterior muscle during the observation of the initial phase of gait. For this purpose, using transcranial magnetic stimulation, we recorded motor evoked potentials (MEPs) during the observation of the second step of an actor's first three steps of gait initiation with (complex gait) or without (normal gait) an obstacle and unstable surface. The results demonstrate that (1) MEPs during the observation of the initial phase of normal gait were significantly increased only at early swing phase, but not other phases (mid-swing, heel contact, mid-stance, and heel off) and (2) MEPs during the observation of the initial phase of complex gait were significantly increased at early swing and also at mid-swing and heel contact phases. These findings provide the first evidence that corticospinal excitability during the observation of gait, especially the initial phase, is modulated in phase- and motor-demanded-dependent manners.
authors.affiliation: Graduate School of Biomedical & Health Sciences, Hiroshima University , Hiroshima , Japan .
authors.forename: Makoto
authors.initials: M
authors.lastname: Takahashi
authors.forename: Natsuko
authors.initials: N
authors.lastname: Uchida
authors.forename: Mami
authors.initials: M
authors.lastname: Yoshida
authors.forename: Nan
authors.initials: N
authors.lastname: Liang
authors.forename: Kimitaka
authors.initials: K
authors.lastname: Nakazawa
authors.forename: Kiyokazu
authors.initials: K
authors.lastname: Sekikawa
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Inamizu
authors.forename: Hironobu
authors.initials: H
authors.lastname: Hamada
mesh_terms: D000328:Adult; D004569:Electroencephalography; D004576:Electromyography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005684:Gait / Q000502:physiology*; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000294:innervation; D019370:Observation; D011712:Pyramidal Tracts / Q000502:physiology*; D013997:Time Factors; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: Action observation; initial phase of gait; transcranial magnetic stimulation