The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions

Ethan C. Hill, Terry J. Housh, Clayton L. Camic, Nathaniel D.M. Jenkins, Cory M. Smith, Kristen C. Cochrane, Joel T. Cramer, Richard J. Schmidt, Molly M. Monaghan, Glen O. Johnson

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

BACKGROUND: Previous investigations have examined the torque and neuromuscular responses to maximal concentric and isometric muscle actions. The literature, however, has paid less attention to the effects of performing maximal eccentric muscle actions. Furthermore, the available information in this regard is contradictory. OBJECTIVE: The purpose of the present investigation was to examine eccentric, isokinetic peak moment (PMe), electromyographic (EMG) amplitude (AMP), EMG mean power frequency (MPF), mechanomyographic (MMG) AMP, and MMG MPF patterns of responses to repeated, maximal, eccentric muscle actions at 60, 120, and 180°/s. METHODS: Twelve resistance-trained men visited the laboratory on three occasions (separated by ≥ 72 h) and performed 30 repeated, maximal, eccentric muscle actions of the dominant leg extensors on an isokinetic dynamometer at randomly ordered velocities of 60, 120, and 180°/s. RESULTS: There were no changes (p > 0.05) across the 30 repeated, eccentric muscle actions for PMe, MMG AMP, and EMG MPF for any of the velocities. There were, however, increases in EMG AMP and decreases in MMG MPF for each velocity. CONCLUSIONS: The decrease in MMG MPF, which reflects the global firing rate of the activated motor units, in conjunction with the lack of change in MMG AMP, which reflects motor unit recruitment, suggested that the increase in EMG AMP was due to motor unit synchronization.

Original languageEnglish (US)
Pages (from-to)1-6
Number of pages6
JournalIsokinetics and Exercise Science
Volume24
Issue number1
DOIs
StatePublished - Feb 27 2016

Fingerprint

Torque
Muscles
Neurophysiological Recruitment
Leg

Keywords

  • Electromyography
  • Isokinetic
  • Mechanomyography
  • Motor control
  • Muscle fatigue
  • Muscle lengthening

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine
  • Physical Therapy, Sports Therapy and Rehabilitation

Cite this

Hill, E. C., Housh, T. J., Camic, C. L., Jenkins, N. D. M., Smith, C. M., Cochrane, K. C., ... Johnson, G. O. (2016). The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions. Isokinetics and Exercise Science, 24(1), 1-6. https://doi.org/10.3233/IES-150591

The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions. / Hill, Ethan C.; Housh, Terry J.; Camic, Clayton L.; Jenkins, Nathaniel D.M.; Smith, Cory M.; Cochrane, Kristen C.; Cramer, Joel T.; Schmidt, Richard J.; Monaghan, Molly M.; Johnson, Glen O.

In: Isokinetics and Exercise Science, Vol. 24, No. 1, 27.02.2016, p. 1-6.

Research output: Contribution to journalArticle

Hill, EC, Housh, TJ, Camic, CL, Jenkins, NDM, Smith, CM, Cochrane, KC, Cramer, JT, Schmidt, RJ, Monaghan, MM & Johnson, GO 2016, 'The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions', Isokinetics and Exercise Science, vol. 24, no. 1, pp. 1-6. https://doi.org/10.3233/IES-150591
Hill, Ethan C. ; Housh, Terry J. ; Camic, Clayton L. ; Jenkins, Nathaniel D.M. ; Smith, Cory M. ; Cochrane, Kristen C. ; Cramer, Joel T. ; Schmidt, Richard J. ; Monaghan, Molly M. ; Johnson, Glen O. / The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions. In: Isokinetics and Exercise Science. 2016 ; Vol. 24, No. 1. pp. 1-6.
@article{f59c2c8d0c0a45b7976ef040c1de2f68,
title = "The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions",
abstract = "BACKGROUND: Previous investigations have examined the torque and neuromuscular responses to maximal concentric and isometric muscle actions. The literature, however, has paid less attention to the effects of performing maximal eccentric muscle actions. Furthermore, the available information in this regard is contradictory. OBJECTIVE: The purpose of the present investigation was to examine eccentric, isokinetic peak moment (PMe), electromyographic (EMG) amplitude (AMP), EMG mean power frequency (MPF), mechanomyographic (MMG) AMP, and MMG MPF patterns of responses to repeated, maximal, eccentric muscle actions at 60, 120, and 180°/s. METHODS: Twelve resistance-trained men visited the laboratory on three occasions (separated by ≥ 72 h) and performed 30 repeated, maximal, eccentric muscle actions of the dominant leg extensors on an isokinetic dynamometer at randomly ordered velocities of 60, 120, and 180°/s. RESULTS: There were no changes (p > 0.05) across the 30 repeated, eccentric muscle actions for PMe, MMG AMP, and EMG MPF for any of the velocities. There were, however, increases in EMG AMP and decreases in MMG MPF for each velocity. CONCLUSIONS: The decrease in MMG MPF, which reflects the global firing rate of the activated motor units, in conjunction with the lack of change in MMG AMP, which reflects motor unit recruitment, suggested that the increase in EMG AMP was due to motor unit synchronization.",
keywords = "Electromyography, Isokinetic, Mechanomyography, Motor control, Muscle fatigue, Muscle lengthening",
author = "Hill, {Ethan C.} and Housh, {Terry J.} and Camic, {Clayton L.} and Jenkins, {Nathaniel D.M.} and Smith, {Cory M.} and Cochrane, {Kristen C.} and Cramer, {Joel T.} and Schmidt, {Richard J.} and Monaghan, {Molly M.} and Johnson, {Glen O.}",
year = "2016",
month = "2",
day = "27",
doi = "10.3233/IES-150591",
language = "English (US)",
volume = "24",
pages = "1--6",
journal = "Isokinetics and Exercise Science",
issn = "0959-3020",
publisher = "IOS Press",
number = "1",

}

TY - JOUR

T1 - The effects of velocity on peak torque and neuromuscular responses during eccentric muscle actions

AU - Hill, Ethan C.

AU - Housh, Terry J.

AU - Camic, Clayton L.

AU - Jenkins, Nathaniel D.M.

AU - Smith, Cory M.

AU - Cochrane, Kristen C.

AU - Cramer, Joel T.

AU - Schmidt, Richard J.

AU - Monaghan, Molly M.

AU - Johnson, Glen O.

PY - 2016/2/27

Y1 - 2016/2/27

N2 - BACKGROUND: Previous investigations have examined the torque and neuromuscular responses to maximal concentric and isometric muscle actions. The literature, however, has paid less attention to the effects of performing maximal eccentric muscle actions. Furthermore, the available information in this regard is contradictory. OBJECTIVE: The purpose of the present investigation was to examine eccentric, isokinetic peak moment (PMe), electromyographic (EMG) amplitude (AMP), EMG mean power frequency (MPF), mechanomyographic (MMG) AMP, and MMG MPF patterns of responses to repeated, maximal, eccentric muscle actions at 60, 120, and 180°/s. METHODS: Twelve resistance-trained men visited the laboratory on three occasions (separated by ≥ 72 h) and performed 30 repeated, maximal, eccentric muscle actions of the dominant leg extensors on an isokinetic dynamometer at randomly ordered velocities of 60, 120, and 180°/s. RESULTS: There were no changes (p > 0.05) across the 30 repeated, eccentric muscle actions for PMe, MMG AMP, and EMG MPF for any of the velocities. There were, however, increases in EMG AMP and decreases in MMG MPF for each velocity. CONCLUSIONS: The decrease in MMG MPF, which reflects the global firing rate of the activated motor units, in conjunction with the lack of change in MMG AMP, which reflects motor unit recruitment, suggested that the increase in EMG AMP was due to motor unit synchronization.

AB - BACKGROUND: Previous investigations have examined the torque and neuromuscular responses to maximal concentric and isometric muscle actions. The literature, however, has paid less attention to the effects of performing maximal eccentric muscle actions. Furthermore, the available information in this regard is contradictory. OBJECTIVE: The purpose of the present investigation was to examine eccentric, isokinetic peak moment (PMe), electromyographic (EMG) amplitude (AMP), EMG mean power frequency (MPF), mechanomyographic (MMG) AMP, and MMG MPF patterns of responses to repeated, maximal, eccentric muscle actions at 60, 120, and 180°/s. METHODS: Twelve resistance-trained men visited the laboratory on three occasions (separated by ≥ 72 h) and performed 30 repeated, maximal, eccentric muscle actions of the dominant leg extensors on an isokinetic dynamometer at randomly ordered velocities of 60, 120, and 180°/s. RESULTS: There were no changes (p > 0.05) across the 30 repeated, eccentric muscle actions for PMe, MMG AMP, and EMG MPF for any of the velocities. There were, however, increases in EMG AMP and decreases in MMG MPF for each velocity. CONCLUSIONS: The decrease in MMG MPF, which reflects the global firing rate of the activated motor units, in conjunction with the lack of change in MMG AMP, which reflects motor unit recruitment, suggested that the increase in EMG AMP was due to motor unit synchronization.

KW - Electromyography

KW - Isokinetic

KW - Mechanomyography

KW - Motor control

KW - Muscle fatigue

KW - Muscle lengthening

UR - http://www.scopus.com/inward/record.url?scp=84960958304&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84960958304&partnerID=8YFLogxK

U2 - 10.3233/IES-150591

DO - 10.3233/IES-150591

M3 - Article

AN - SCOPUS:84960958304

VL - 24

SP - 1

EP - 6

JO - Isokinetics and Exercise Science

JF - Isokinetics and Exercise Science

SN - 0959-3020

IS - 1

ER -