Repeatability of maximal voluntary force and of surface EMG variables during voluntary isometric contraction of quadriceps muscles in healthy subjects

Rainoldi, A., Bullock-Saxton, J.E., Cavarretta, F. and Hogan, N. (2001) Repeatability of maximal voluntary force and of surface EMG variables during voluntary isometric contraction of quadriceps muscles in healthy subjects. Journal of Electromyography And Kinesiology, 11 6: 425-438. doi:10.1016/S1050-6411(01)00022-0


Author Rainoldi, A.
Bullock-Saxton, J.E.
Cavarretta, F.
Hogan, N.
Title Repeatability of maximal voluntary force and of surface EMG variables during voluntary isometric contraction of quadriceps muscles in healthy subjects
Journal name Journal of Electromyography And Kinesiology   Check publisher's open access policy
ISSN 1050-6411
1873-5711
Publication date 2001-12
Sub-type Article (original research)
DOI 10.1016/S1050-6411(01)00022-0
Volume 11
Issue 6
Start page 425
End page 438
Total pages 14
Editor Moshe Solomonow
Toshio Moritani
Place of publication Oxford, England
Publisher Elsevier Science
Collection year 2001
Language eng
Subject C1
321024 Rehabilitation and Therapy - Occupational and Physical
730303 Occupational, speech and physiotherapy
Abstract The repeatability of initial values and rate of change of EMG signal mean spectral frequency (MNF), average rectified values (ARV), muscle fiber conduction velocity (CV) and maximal voluntary contraction (MVC) was investigated in the vastus medialis obliquus (VMO) and vastus lateralis (VL) muscles of both legs of nine healthy male subjects during voluntary, isometric contractions sustained for 50 s at 50% MVC. The values of MVC were recorded for both legs three times on each day and for three subsequent days, while the EMG signals have been recorded twice a day for three subsequent days. The degree of repeatability was investigated using the Fisher test based upon the ANalysis Of VAriance (ANOVA), the Standard Error of the Mean (SEM) and the Intraclass Correlation Coefficient (ICC). Data collected showed a high level of repeatability of MVC measurement (normalized SEM from 1.1% to 6.4% of the mean). MNF and ARV initial values also showed a high level of repeatability (ICC > 70% for all muscles and legs except right VMO). At 50% MVC level no relevant pattern of fatigue was observed for the VMO and VL muscles, suggesting that other portions of the quadriceps might have contributed to the generated effort. These observations seem to suggest that in the investigation of muscles belonging to a multi-muscular group at submaximal level, the more selective electrically elicited contractions should be preferred to voluntary contractions. (C) 2001 Elsevier Science Ltd. All rights reserved.
Keyword Neurosciences
Physiology
Rehabilitation
Sport Sciences
Isometric Contraction
Torque Measurement
Vastus Lateralis
Vastus Medialis Obliquus Surface Electromyography
Fatigue
Repeatability
Conduction Velocity
Spectral Frequency
Amplitude Variables
Anova
Icc
Myoelectric Signals
Conduction-velocity
Median Frequency
Vastus Medialis
Power Spectra
Back Muscles
Electromyogram
Reliability
Reproducibility
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collection: School of Health and Rehabilitation Sciences Publications
 
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Created: Tue, 14 Aug 2007, 16:44:58 EST