Electromyographic activity of cat hindlimb flexors and extensors during locomotion at varying speeds and inclines

David J Pierotti, Roland R. Roy, Robert J. Gregor, V. Reggie Edgerton

Research output: Contribution to journalArticle

73 Citations (Scopus)

Abstract

Electromyographic activity (EMG) was used to determine how hindlimb muscle activation patterns are modified as speed and incline of locomotion are varied in treadmill-trained cats. EMG was recorded using chronically implanted i.m. electrodes from the soleus, medial gastrocnemius, gluteus medius, and tibialis anterior muscles of adult cats during treadmill locomotion at a range of speeds and inclines. The patterns of changes in EMG activity at varying speeds and inclines were similar in all cats. Across speeds, the integrated EMG per step decreased for the soleus but remained constant for the other muscles. The integrated EMG per step was elevated in all muscles at higher inclines. Generally, with increased speed or incline the mean EMG per step was elevated in the medial gastrocnemius, gluteus medis, and tibialis anterior, the largest increase seen in the medial gastrocnemius. Soleus mean EMG per step remained unchanged with increased speed, but showed an absolute increase at the higher inclines. The integrated EMG per minute was always highest for the soleus followed by the medial gastrocnemius, and always lowest for the tibialis anterior. At the faster speeds, the 'on-time' increased in the tibialis anterior and decreased in the other muscles. These data suggest that the number of motor units activated and/or their firing frequencies increased in the medial gastrocnemius and the gluteus medius during locomotion at faster speeds or larger inclines, while relatively little change occurred in the soleus and tibialis anterior. These data also suggest that while there is considerable modulation of the level and duration of excitation of the extensor motor pools there is relatively little modulation of the flexor motor pools to adjust for both the speed and the incline of locomotion.

Original languageEnglish (US)
Pages (from-to)57-66
Number of pages10
JournalBrain Research
Volume481
Issue number1
DOIs
StatePublished - Feb 27 1989
Externally publishedYes

Fingerprint

Locomotion
Hindlimb
Cats
Muscles
Implanted Electrodes

Keywords

  • Extensor
  • Flexor
  • Incline
  • Intramuscular electromyography
  • Motor pool
  • Treadmill locomotion

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

Cite this

Electromyographic activity of cat hindlimb flexors and extensors during locomotion at varying speeds and inclines. / Pierotti, David J; Roy, Roland R.; Gregor, Robert J.; Reggie Edgerton, V.

In: Brain Research, Vol. 481, No. 1, 27.02.1989, p. 57-66.

Research output: Contribution to journalArticle

Pierotti, David J ; Roy, Roland R. ; Gregor, Robert J. ; Reggie Edgerton, V. / Electromyographic activity of cat hindlimb flexors and extensors during locomotion at varying speeds and inclines. In: Brain Research. 1989 ; Vol. 481, No. 1. pp. 57-66.
@article{812ce728fcb44ac181351071a9a5e50e,
title = "Electromyographic activity of cat hindlimb flexors and extensors during locomotion at varying speeds and inclines",
abstract = "Electromyographic activity (EMG) was used to determine how hindlimb muscle activation patterns are modified as speed and incline of locomotion are varied in treadmill-trained cats. EMG was recorded using chronically implanted i.m. electrodes from the soleus, medial gastrocnemius, gluteus medius, and tibialis anterior muscles of adult cats during treadmill locomotion at a range of speeds and inclines. The patterns of changes in EMG activity at varying speeds and inclines were similar in all cats. Across speeds, the integrated EMG per step decreased for the soleus but remained constant for the other muscles. The integrated EMG per step was elevated in all muscles at higher inclines. Generally, with increased speed or incline the mean EMG per step was elevated in the medial gastrocnemius, gluteus medis, and tibialis anterior, the largest increase seen in the medial gastrocnemius. Soleus mean EMG per step remained unchanged with increased speed, but showed an absolute increase at the higher inclines. The integrated EMG per minute was always highest for the soleus followed by the medial gastrocnemius, and always lowest for the tibialis anterior. At the faster speeds, the 'on-time' increased in the tibialis anterior and decreased in the other muscles. These data suggest that the number of motor units activated and/or their firing frequencies increased in the medial gastrocnemius and the gluteus medius during locomotion at faster speeds or larger inclines, while relatively little change occurred in the soleus and tibialis anterior. These data also suggest that while there is considerable modulation of the level and duration of excitation of the extensor motor pools there is relatively little modulation of the flexor motor pools to adjust for both the speed and the incline of locomotion.",
keywords = "Extensor, Flexor, Incline, Intramuscular electromyography, Motor pool, Treadmill locomotion",
author = "Pierotti, {David J} and Roy, {Roland R.} and Gregor, {Robert J.} and {Reggie Edgerton}, V.",
year = "1989",
month = "2",
day = "27",
doi = "10.1016/0006-8993(89)90485-X",
language = "English (US)",
volume = "481",
pages = "57--66",
journal = "Brain Research",
issn = "0006-8993",
publisher = "Elsevier",
number = "1",

}

TY - JOUR

T1 - Electromyographic activity of cat hindlimb flexors and extensors during locomotion at varying speeds and inclines

AU - Pierotti, David J

AU - Roy, Roland R.

AU - Gregor, Robert J.

AU - Reggie Edgerton, V.

PY - 1989/2/27

Y1 - 1989/2/27

N2 - Electromyographic activity (EMG) was used to determine how hindlimb muscle activation patterns are modified as speed and incline of locomotion are varied in treadmill-trained cats. EMG was recorded using chronically implanted i.m. electrodes from the soleus, medial gastrocnemius, gluteus medius, and tibialis anterior muscles of adult cats during treadmill locomotion at a range of speeds and inclines. The patterns of changes in EMG activity at varying speeds and inclines were similar in all cats. Across speeds, the integrated EMG per step decreased for the soleus but remained constant for the other muscles. The integrated EMG per step was elevated in all muscles at higher inclines. Generally, with increased speed or incline the mean EMG per step was elevated in the medial gastrocnemius, gluteus medis, and tibialis anterior, the largest increase seen in the medial gastrocnemius. Soleus mean EMG per step remained unchanged with increased speed, but showed an absolute increase at the higher inclines. The integrated EMG per minute was always highest for the soleus followed by the medial gastrocnemius, and always lowest for the tibialis anterior. At the faster speeds, the 'on-time' increased in the tibialis anterior and decreased in the other muscles. These data suggest that the number of motor units activated and/or their firing frequencies increased in the medial gastrocnemius and the gluteus medius during locomotion at faster speeds or larger inclines, while relatively little change occurred in the soleus and tibialis anterior. These data also suggest that while there is considerable modulation of the level and duration of excitation of the extensor motor pools there is relatively little modulation of the flexor motor pools to adjust for both the speed and the incline of locomotion.

AB - Electromyographic activity (EMG) was used to determine how hindlimb muscle activation patterns are modified as speed and incline of locomotion are varied in treadmill-trained cats. EMG was recorded using chronically implanted i.m. electrodes from the soleus, medial gastrocnemius, gluteus medius, and tibialis anterior muscles of adult cats during treadmill locomotion at a range of speeds and inclines. The patterns of changes in EMG activity at varying speeds and inclines were similar in all cats. Across speeds, the integrated EMG per step decreased for the soleus but remained constant for the other muscles. The integrated EMG per step was elevated in all muscles at higher inclines. Generally, with increased speed or incline the mean EMG per step was elevated in the medial gastrocnemius, gluteus medis, and tibialis anterior, the largest increase seen in the medial gastrocnemius. Soleus mean EMG per step remained unchanged with increased speed, but showed an absolute increase at the higher inclines. The integrated EMG per minute was always highest for the soleus followed by the medial gastrocnemius, and always lowest for the tibialis anterior. At the faster speeds, the 'on-time' increased in the tibialis anterior and decreased in the other muscles. These data suggest that the number of motor units activated and/or their firing frequencies increased in the medial gastrocnemius and the gluteus medius during locomotion at faster speeds or larger inclines, while relatively little change occurred in the soleus and tibialis anterior. These data also suggest that while there is considerable modulation of the level and duration of excitation of the extensor motor pools there is relatively little modulation of the flexor motor pools to adjust for both the speed and the incline of locomotion.

KW - Extensor

KW - Flexor

KW - Incline

KW - Intramuscular electromyography

KW - Motor pool

KW - Treadmill locomotion

UR - http://www.scopus.com/inward/record.url?scp=0024520912&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0024520912&partnerID=8YFLogxK

U2 - 10.1016/0006-8993(89)90485-X

DO - 10.1016/0006-8993(89)90485-X

M3 - Article

C2 - 2706467

AN - SCOPUS:0024520912

VL - 481

SP - 57

EP - 66

JO - Brain Research

JF - Brain Research

SN - 0006-8993

IS - 1

ER -