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Use of muscle synergies and wavelet transforms to identify fatigue during squatting

Smale, Kenneth B. ; Shourijeh, Mohammad S. and Benoit, Daniel L. LU (2016) In Journal of Electromyography and Kinesiology 28. p.158-166
Abstract

The objective of this study was to supplement continuous wavelet transforms with muscle synergies in a fatigue analysis to better describe the combination of decreased firing frequency and altered activation profiles during dynamic muscle contractions. Nine healthy young individuals completed the dynamic tasks before and after they squatted with a standard Olympic bar until complete exhaustion. Electromyography (EMG) profiles were analyzed with a novel concatenated non-negative matrix factorization method that decomposed EMG signals into muscle synergies. Muscle synergy analysis provides the activation pattern of the muscles while continuous wavelet transforms output the temporal frequency content of the EMG signals. Synergy analysis... (More)

The objective of this study was to supplement continuous wavelet transforms with muscle synergies in a fatigue analysis to better describe the combination of decreased firing frequency and altered activation profiles during dynamic muscle contractions. Nine healthy young individuals completed the dynamic tasks before and after they squatted with a standard Olympic bar until complete exhaustion. Electromyography (EMG) profiles were analyzed with a novel concatenated non-negative matrix factorization method that decomposed EMG signals into muscle synergies. Muscle synergy analysis provides the activation pattern of the muscles while continuous wavelet transforms output the temporal frequency content of the EMG signals. Synergy analysis revealed subtle changes in two-legged squatting after fatigue while differences in one-legged squatting were more pronounced and included the shift from a general co-activation of muscles in the pre-fatigue state to a knee extensor dominant weighting post-fatigue. Continuous wavelet transforms showed major frequency content decreases in two-legged squatting after fatigue while very few frequency changes occurred in one-legged squatting. It was observed that the combination of methods is an effective way of describing muscle fatigue and that muscle activation patterns play a very important role in maintaining the overall joint kinetics after fatigue.

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author
; and
publishing date
type
Contribution to journal
publication status
published
keywords
Mean frequency, Muscle activation, Non-negative matrix factorization, Root mean square
in
Journal of Electromyography and Kinesiology
volume
28
pages
158 - 166
publisher
Elsevier
external identifiers
  • pmid:27156237
  • scopus:84964978273
ISSN
1050-6411
DOI
10.1016/j.jelekin.2016.04.008
language
English
LU publication?
no
additional info
Publisher Copyright: © 2016 Elsevier Ltd.
id
9295c9d0-1848-46a4-94d4-860f8e300f59
date added to LUP
2023-08-24 16:33:44
date last changed
2024-06-15 06:50:12
@article{9295c9d0-1848-46a4-94d4-860f8e300f59,
  abstract     = {{<p>The objective of this study was to supplement continuous wavelet transforms with muscle synergies in a fatigue analysis to better describe the combination of decreased firing frequency and altered activation profiles during dynamic muscle contractions. Nine healthy young individuals completed the dynamic tasks before and after they squatted with a standard Olympic bar until complete exhaustion. Electromyography (EMG) profiles were analyzed with a novel concatenated non-negative matrix factorization method that decomposed EMG signals into muscle synergies. Muscle synergy analysis provides the activation pattern of the muscles while continuous wavelet transforms output the temporal frequency content of the EMG signals. Synergy analysis revealed subtle changes in two-legged squatting after fatigue while differences in one-legged squatting were more pronounced and included the shift from a general co-activation of muscles in the pre-fatigue state to a knee extensor dominant weighting post-fatigue. Continuous wavelet transforms showed major frequency content decreases in two-legged squatting after fatigue while very few frequency changes occurred in one-legged squatting. It was observed that the combination of methods is an effective way of describing muscle fatigue and that muscle activation patterns play a very important role in maintaining the overall joint kinetics after fatigue.</p>}},
  author       = {{Smale, Kenneth B. and Shourijeh, Mohammad S. and Benoit, Daniel L.}},
  issn         = {{1050-6411}},
  keywords     = {{Mean frequency; Muscle activation; Non-negative matrix factorization; Root mean square}},
  language     = {{eng}},
  month        = {{06}},
  pages        = {{158--166}},
  publisher    = {{Elsevier}},
  series       = {{Journal of Electromyography and Kinesiology}},
  title        = {{Use of muscle synergies and wavelet transforms to identify fatigue during squatting}},
  url          = {{http://dx.doi.org/10.1016/j.jelekin.2016.04.008}},
  doi          = {{10.1016/j.jelekin.2016.04.008}},
  volume       = {{28}},
  year         = {{2016}},
}