Journal article
Global electromyographic signal characteristics depend on maximal isometric contraction method in the knee extensors
Journal of electromyography and kinesiology, Vol.42, pp.111-116
10/01/2018
DOI: 10.1016/j.jelekin.2018.07.002
PMID: 30015134
Abstract
Objective: To determine if maximal isometric contraction (MVIC) method (i.e., ramp (MVICRAMP) versus traditional MVIC) influences (1) maximal voluntary isometric torque (MVIT) production of the knee extensors, (2) electromyographic signal amplitude (EMG(AMP)), and (3) EMG mean power frequency (EMG(MPF)) of the rectus femoris and vastus lateralis in moderately-to highly-activated subjects. We hypothesized that EMG(AMP) would be greater during the MVICRAMP than MVIC muscle contractions, but that there would be no difference in MVIT.
Approach: Twenty-five males (23.4 +/- 3.4 y; % voluntary activation = 93.9 +/- 5.1%) visited the laboratory and completed MVIC(RAMP)s and MVICs. During all contractions, leg extensor torque and sEMG signals from the vastus lateralis (VL) and rectus femoris (RF) were recorded.
Main results: There was no significant difference in the MVIT produced (p=0.65) or in EMG(MPF) (p=0.052) during MVICRAMP versus MVIC. However, EMG(AMP) was 18.1% higher during the MVICRAMP than MVIC (p=0.004).
Significance: Maximal isometric muscle contraction method significantly influenced EMG(AMP), and had a moderate effect on EMG(MPF) (d=0.49). Investigators who utilize MVICs to determine maximal EMG signal amplitude and frequency to normalize their EMG signals should be aware of these differences.
Details
- Title: Subtitle
- Global electromyographic signal characteristics depend on maximal isometric contraction method in the knee extensors
- Creators
- Patrick M. Tomko - Oklahoma State UniversityRyan J. Colquhoun - Oklahoma State UniversityMitchel A. Magrini - Oklahoma State UniversityTyler W. D. Muddle - Oklahoma State UniversityNathaniel D. M. Jenkins - Oklahoma State University
- Resource Type
- Journal article
- Publication Details
- Journal of electromyography and kinesiology, Vol.42, pp.111-116
- DOI
- 10.1016/j.jelekin.2018.07.002
- PMID
- 30015134
- NLM abbreviation
- J Electromyogr Kinesiol
- ISSN
- 1050-6411
- eISSN
- 1873-5711
- Publisher
- Elsevier
- Number of pages
- 6
- Language
- English
- Date published
- 10/01/2018
- Academic Unit
- Center for Social Science Innovation; Injury Prevention Research Center; Health, Sport, and Human Physiology
- Record Identifier
- 9984259655302771
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