Quantifying the effects of electrode distance from the innervation zone on the electromyographic amplitude versus torque relationships

Trent J. Herda, Jorge M. Zuniga, Eric D. Ryan, Clayton L. Camic, Haley C. Bergstrom, Doug B. Smith, Joseph P. Weir, Joel T. Cramer, Terry J. Housh

Research output: Contribution to journalArticle

8 Scopus citations

Abstract

The present study applied a log-transformation model to compare the electromyographic (EMG) amplitude versus torque relationships from monopolar EMG signals up to 35 mm proximal and distal from the innervation zone (IZ). Seven men (age = 23 ± 2 year; mass = 82 ± 10 kg) and two women (age = 21 ± 1 year; mass = 62 ± 8 kg) performed isometric ramp contractions of the right leg extensors with an eight-channel linear electrode array positioned over the vastus lateralis with the IZ located between channels 4 and 5. Linear regression models were fit to the log-transformed monopolar EMGRMS-torque relationships with the b terms (slope) and the a terms (Y-intercept) calculated for each channel and subject. The b terms for channels 4, 5, and 6 were higher (P ≤ 0.05) than the more distal channels 7 and 8 (P < 0.05). In contrast, there were no differences (P > 0.05) among the a terms of the eight channels. Thus, the shapes of the monopolar EMGRMS-torque relationships were altered as a function of distance between the IZ and recording area, which may be helpful for clinicians and researchers who infer changes in motor control strategies based on the shapes of the EMGRMS-torque relationships.

Original languageEnglish (US)
Pages (from-to)315-324
Number of pages10
JournalPhysiological Measurement
Volume34
Issue number3
DOIs
StatePublished - Mar 2013

Keywords

  • EMG
  • innervation zone
  • linear array
  • motor unit activation strategies

ASJC Scopus subject areas

  • Biophysics
  • Physiology
  • Biomedical Engineering
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Quantifying the effects of electrode distance from the innervation zone on the electromyographic amplitude versus torque relationships'. Together they form a unique fingerprint.

  • Cite this