Maximal activation of the human diaphragm but not inspiratory intercostal muscles during static inspiratory efforts.

Journal Article (Journal Article)

It is widely held that transdiaphragmatic pressure is a reliable index of the extent of central activation of the diaphragm but the maximal voluntary transdiaphragmatic pressure is lower during inspiratory than expulsive efforts. To determine whether the diaphragm is fully activated during the two manoeuvres supramaximal stimuli were delivered to both phrenic nerves during maximal efforts. No discernible twitch was evoked during 30-55% of attempted maximal efforts with either voluntary manoeuvre. Thus the difference in maximal transdiaphragmatic pressure between the manoeuvres must reflect changes in chest-wall geometry or mechanics rather than in the phrenic motor outflow. Inspiratory intercostal muscle activity was consistently submaximal during maximal inspiratory efforts.

Full Text

Duke Authors

Cited Authors

  • McKenzie, DK; Plassman, BL; Gandevia, SC

Published Date

  • June 17, 1988

Published In

Volume / Issue

  • 89 / 1

Start / End Page

  • 63 - 68

PubMed ID

  • 3041320

International Standard Serial Number (ISSN)

  • 0304-3940

Digital Object Identifier (DOI)

  • 10.1016/0304-3940(88)90481-8


  • eng

Conference Location

  • Ireland