SUBJECTIVE AND ELECTROMYOGRAPHIC ASSESSMENT OF ISOMETRIC MUSCLE CONTRACTIONS

Abstract

Forty male subjects were asked to pull either 25% or 50% of their maximal voluntary contraction on an isometric dynamometer handle. During the pull, they were asked to rate the pain experienced in the muscles on a five-point scale. During the task, the active muscle was continuously monitored by an EMG. The results indicated that individuals are able to predict their maximal endurance when concentrating on a dominant stimulus in a physical task. The EMG analyses indicated that a differentiation can be made between physiological and psychological aspects of fatigue. The point in time when the EMG significantly increased in amplitude is interpreted to be the time when, due to motor unit impairment, the active muscle is fatigued. Additional contraction time was proposed to result from cortical recruitment, the length of which was determined by motivational elements.

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Document Details

Document Type
Technical Report
Publication Date
Mar 26, 1968
Accession Number
AD0669595

Entities

People

  • Andree J. Lloyd
  • Joseph H. Voor
  • Thomas Thieman

Organizations

  • United States Army Medical Research Laboratory

Tags

DTIC Thesaurus Topics

  • Abstracts
  • Amplitude
  • Analysis Of Variance
  • Biomedical Research
  • Blood Flow
  • Business Administration
  • Data Science
  • Dynamometers
  • Electrodes
  • Experimental Design
  • Human Behavior
  • Information Science
  • Intensity
  • Lower Extremity
  • New York
  • Physical Disabilities
  • Strain Gages

Fields of Study

  • Psychology

Readers

  • Clinical Trial Research.
  • Educational Psychology
  • Speech Processing/Speech Recognition.