Heterogeneous activity of the human genioglossus muscle assessed by multiple bipolar fine-wire electrodes

Peter R. Eastwood, Garry T. Allison, Kelly L. Shepherd, Irene Szollosi, David R. Hillman

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)


Genioglossus (GG) electrical activity [measured by electromyogram (EMGgg)] is best measured by intramuscular electrodes; however, the homogeneity of EMGgg is undefined. We investigated the relationships between EMGgg and the site from which activity was measured to determine whether and to what extent inhomogeneity in activity occurred. Eight healthy human volunteers underwent ultrasound to determine GG depth and width. Four pairs of electrodes were then inserted percutaneously into the left and right GG muscle, anteriorly and posteriorly. Additional configurations were obtained by connecting electrodes across the midline and along each muscle belly. EMGgg activity was simultaneously recorded from these 10 configurations at rest and during various respiratory maneuvers. Heterogeneous behavior of the GG was evidenced by 1) the variable presence of phasic EMGgg at rest, which was undetectable in two subjects but evident in 65% of configurations in six subjects and present in all configurations in all subjects during voluntary hyperventilation; 2) a greater amplitude of EMGgg response to pharyngeal square-wave negative pressure in anterior than posterior configurations (14.1 ± 7.1 vs. 8.5 ± 5.1% of maximum, P < 0.05); and 3) variable (linear and alinear) relationships between EMGgg and lingual force within and between subjects. We hypothesize that regional differences in density and type of muscle fiber are the most likely sources of heterogeneity in these responses.

Original languageEnglish
Pages (from-to)1849-1858
Number of pages10
JournalJournal of Applied Physiology
Issue number5
Publication statusPublished - May 2003
Externally publishedYes

Bibliographical note

Copyright 2017 Elsevier B.V., All rights reserved.


  • Dilator
  • Obstructive sleep apnoea
  • Ultrasound
  • Upper airway collapse


Dive into the research topics of 'Heterogeneous activity of the human genioglossus muscle assessed by multiple bipolar fine-wire electrodes'. Together they form a unique fingerprint.

Cite this