title: Voluntary breathing increases corticospinal excitability of lower limb muscle during isometric contraction.
abstract: The aim of the present study was to determine the effects of voluntary breathing on corticospinal excitability of a leg muscle during isometric contraction. Seven subjects performed 5-s isometric knee extension at the intensity of 10% of maximal voluntary contraction (10% MVC). During the 10% MVC, the subjects were instructed to breath normally (NORM) or to inhale (IN) or exhale (OUT) once as fast as possible. Motor-evoked potentials (MEPs) induced by transcranialmagnetic stimulation in the right vastus lateralis (VL) during the 10% MVC were recorded and compared during the three breathing tasks. MEPs in IN and OUT were significantly higher than that in NORM. Effort sense of breathing was significantly higher in IN and OUT than in NORM. There was a significant positive correlation between MEP and effort sense of breathing. These results suggest that activation of the breathing-associated cortical areas with voluntary breathing is involved in the increase in corticospinal excitability of the VL during isometric contraction.
authors.affiliation: Graduate School of Education, Hokkaido University, Sapporo, Japan. Electronic address: kazuki.shirakawa@edu.hokudai.ac.jp.
authors.forename: Kazuki
authors.initials: K
authors.lastname: Shirakawa
authors.affiliation: Department of Human Developmental Sciences, Faculty of Education, Hokkaido University, Sapporo, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Yunoki
authors.affiliation: Department of Sport Science and Physical Education, Payame Noor University, Tehran, Iran.
authors.forename: Roghayyeh
authors.initials: R
authors.lastname: Afroundeh
authors.affiliation: Graduate School of Education, Hokkaido University, Sapporo, Japan.
authors.forename: Chang-Shun
authors.initials: CS
authors.lastname: Lian
authors.affiliation: Department of Health and Physical Education, Joetsu University of Education, Joetsu, Japan.
authors.forename: Ryouta
authors.initials: R
authors.lastname: Matsuura
authors.affiliation: Department of Human Developmental Sciences, Faculty of Education, Hokkaido University, Sapporo, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Ohtsuka
authors.affiliation: Department of Human Developmental Sciences, Faculty of Education, Hokkaido University, Sapporo, Japan.
authors.forename: Tokuo
authors.initials: T
authors.lastname: Yano
mesh_terms: D004576:Electromyography; D019054:Evoked Potentials, Motor; D006801:Humans; D007537:Isometric Contraction; D007866:Leg / Q000502:physiology*; D008297:Male; D011712:Pyramidal Tracts / Q000502:physiology*; D012119:Respiration; D050781:Transcranial Magnetic Stimulation; D014836:Volition / Q000502:physiology; D055815:Young Adult
keywords: Corticospinal excitability; Lower limb muscle; Motor-evoked potential; Transcranial magnetic stimulation; Voluntary breathing