Medial-lateral hamstring electromyographic activity during maximum isometric knee flexion at different angles

Ira Fiebert, Craig H. Pahl, E. Brooks Applegate, Neil I. Spielholz, Karen Beernik

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The purpose of this study was to investigate knee flexion torque and changes in electromyographic (EMG) activity of the medial and lateral hamstrings during isometric knee flexion at different angles. Thirty-four subjects, 17 female and 17 mate, between 21 and 33 years of age, with no history of right knee pathology volunteered to participate. Subjects were positioned prone on the Cybex II with their right lower extremity secured in knee flexion. Surface electrodes were placed over the medial and lateral hamstring muscles. Each test session consisted of nine maximal isometric knee flexion contractions. Three contractions, of six seconds each, were recorded at 30, 60, and 90 degrees of knee flexion. Recordings of maximum torque and averaged EMG were made by the Cybex II and the Bioscope, respectively. The results showed statistically significant findings: (1) decreased torque as knee flexion increased (P < 0.0005); (2) men demonstrated greater torque than women (P < 0.05); and (3) EMG activity for both the medial and lateral hamstrings decreased as knee flexion increased with differences between 90 and 30°, and 90 and 60°(P < 0.05). We concluded that the decrease in torque output with increased knee flexion is consistent with present knowledge. The coordinated pattern of declining EMG activity with increased knee flexion for both the medial and lateral hamstring muscles requires further investigation.

Original languageEnglish
Pages (from-to)157-162
Number of pages6
JournalIsokinetics and Exercise Science
Volume6
Issue number2
StatePublished - Dec 1 1996

Fingerprint

Knee
Torque
Lower Extremity
Electrodes
Pathology

Keywords

  • Electromyographic (EMG) activity
  • Hamstrings
  • Isometric contractions
  • Torque

ASJC Scopus subject areas

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

Cite this

Medial-lateral hamstring electromyographic activity during maximum isometric knee flexion at different angles. / Fiebert, Ira; Pahl, Craig H.; Applegate, E. Brooks; Spielholz, Neil I.; Beernik, Karen.

In: Isokinetics and Exercise Science, Vol. 6, No. 2, 01.12.1996, p. 157-162.

Research output: Contribution to journalArticle

Fiebert, Ira ; Pahl, Craig H. ; Applegate, E. Brooks ; Spielholz, Neil I. ; Beernik, Karen. / Medial-lateral hamstring electromyographic activity during maximum isometric knee flexion at different angles. In: Isokinetics and Exercise Science. 1996 ; Vol. 6, No. 2. pp. 157-162.
@article{4e00ad8489104c8b82926208aefc4eee,
title = "Medial-lateral hamstring electromyographic activity during maximum isometric knee flexion at different angles",
abstract = "The purpose of this study was to investigate knee flexion torque and changes in electromyographic (EMG) activity of the medial and lateral hamstrings during isometric knee flexion at different angles. Thirty-four subjects, 17 female and 17 mate, between 21 and 33 years of age, with no history of right knee pathology volunteered to participate. Subjects were positioned prone on the Cybex II with their right lower extremity secured in knee flexion. Surface electrodes were placed over the medial and lateral hamstring muscles. Each test session consisted of nine maximal isometric knee flexion contractions. Three contractions, of six seconds each, were recorded at 30, 60, and 90 degrees of knee flexion. Recordings of maximum torque and averaged EMG were made by the Cybex II and the Bioscope, respectively. The results showed statistically significant findings: (1) decreased torque as knee flexion increased (P < 0.0005); (2) men demonstrated greater torque than women (P < 0.05); and (3) EMG activity for both the medial and lateral hamstrings decreased as knee flexion increased with differences between 90 and 30°, and 90 and 60°(P < 0.05). We concluded that the decrease in torque output with increased knee flexion is consistent with present knowledge. The coordinated pattern of declining EMG activity with increased knee flexion for both the medial and lateral hamstring muscles requires further investigation.",
keywords = "Electromyographic (EMG) activity, Hamstrings, Isometric contractions, Torque",
author = "Ira Fiebert and Pahl, {Craig H.} and Applegate, {E. Brooks} and Spielholz, {Neil I.} and Karen Beernik",
year = "1996",
month = "12",
day = "1",
language = "English",
volume = "6",
pages = "157--162",
journal = "Isokinetics and Exercise Science",
issn = "0959-3020",
publisher = "IOS Press",
number = "2",

}

TY - JOUR

T1 - Medial-lateral hamstring electromyographic activity during maximum isometric knee flexion at different angles

AU - Fiebert, Ira

AU - Pahl, Craig H.

AU - Applegate, E. Brooks

AU - Spielholz, Neil I.

AU - Beernik, Karen

PY - 1996/12/1

Y1 - 1996/12/1

N2 - The purpose of this study was to investigate knee flexion torque and changes in electromyographic (EMG) activity of the medial and lateral hamstrings during isometric knee flexion at different angles. Thirty-four subjects, 17 female and 17 mate, between 21 and 33 years of age, with no history of right knee pathology volunteered to participate. Subjects were positioned prone on the Cybex II with their right lower extremity secured in knee flexion. Surface electrodes were placed over the medial and lateral hamstring muscles. Each test session consisted of nine maximal isometric knee flexion contractions. Three contractions, of six seconds each, were recorded at 30, 60, and 90 degrees of knee flexion. Recordings of maximum torque and averaged EMG were made by the Cybex II and the Bioscope, respectively. The results showed statistically significant findings: (1) decreased torque as knee flexion increased (P < 0.0005); (2) men demonstrated greater torque than women (P < 0.05); and (3) EMG activity for both the medial and lateral hamstrings decreased as knee flexion increased with differences between 90 and 30°, and 90 and 60°(P < 0.05). We concluded that the decrease in torque output with increased knee flexion is consistent with present knowledge. The coordinated pattern of declining EMG activity with increased knee flexion for both the medial and lateral hamstring muscles requires further investigation.

AB - The purpose of this study was to investigate knee flexion torque and changes in electromyographic (EMG) activity of the medial and lateral hamstrings during isometric knee flexion at different angles. Thirty-four subjects, 17 female and 17 mate, between 21 and 33 years of age, with no history of right knee pathology volunteered to participate. Subjects were positioned prone on the Cybex II with their right lower extremity secured in knee flexion. Surface electrodes were placed over the medial and lateral hamstring muscles. Each test session consisted of nine maximal isometric knee flexion contractions. Three contractions, of six seconds each, were recorded at 30, 60, and 90 degrees of knee flexion. Recordings of maximum torque and averaged EMG were made by the Cybex II and the Bioscope, respectively. The results showed statistically significant findings: (1) decreased torque as knee flexion increased (P < 0.0005); (2) men demonstrated greater torque than women (P < 0.05); and (3) EMG activity for both the medial and lateral hamstrings decreased as knee flexion increased with differences between 90 and 30°, and 90 and 60°(P < 0.05). We concluded that the decrease in torque output with increased knee flexion is consistent with present knowledge. The coordinated pattern of declining EMG activity with increased knee flexion for both the medial and lateral hamstring muscles requires further investigation.

KW - Electromyographic (EMG) activity

KW - Hamstrings

KW - Isometric contractions

KW - Torque

UR - http://www.scopus.com/inward/record.url?scp=0030482563&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0030482563&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:0030482563

VL - 6

SP - 157

EP - 162

JO - Isokinetics and Exercise Science

JF - Isokinetics and Exercise Science

SN - 0959-3020

IS - 2

ER -