Effects of fatigue on voluntary electromechanical and relaxation electromechanical delay
Deutscher übersetzter Titel: | Die Wirkung der Ermüdung auf die willkürliche elektromechanische Verzögerung und die elektromechanische Verzögerung der Relaxation |
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Autor: | Smith, Cory M.; Housh, Terry J.; Hill, Ethan C.; Keller, Joshua L.; Johnson, Glen O.; Schmidt, Richard J. |
Erschienen in: | International journal of sports medicine |
Veröffentlicht: | 38 (2017), 10, S. 763-769, Lit. |
Format: | Literatur (SPOLIT) |
Publikationstyp: | Zeitschriftenartikel |
Medienart: | Elektronische Ressource (online) Gedruckte Ressource |
Sprache: | Englisch |
ISSN: | 0172-4622, 1439-3964 |
DOI: | 10.1055/s-0043-115734 |
Schlagworte: | |
Online Zugang: | |
Erfassungsnummer: | PU201710008463 |
Quelle: | BISp |
Abstract des Autors
The purposes of the present study were to examine: 1) the effects of fatigue on electromechanical delay from the onsets of the electromyographic signal to force production (EMDE-F), the onsets of the electromyographic to mechanomyographic signals (EMDE-M), the onsets of the mechanomyographic signal to force production (EMDM-F), as well as the cessations of the electromyographic to force production (R-EMDE-F), cessation of the electromyographic to mechanomyographic signals (R-EMDE-M), and cessations of the mechanomyographic signal to force production (R-EMDM-F); and 2) the relative contributions from EMDE-M and EMDM-F to EMDE-F as well as R-EMDE-M and R-EMDM-F to R-EMDE-F from the vastus lateralis in non-fatigued and fatigued states. The values EMDE-F, EMDE-M, EMDM-F, R-EMDE-F, R-EMDE-M and R-EMDM-F were calculated during maximal voluntary isometric contractions, before and after 70% 1-repetition maximum leg extensions to failure. There were significant pretest to posttest increases in EMDE-F (73%;p<0.01), EMDE-M (99%;p<0.01), EMDM-F (60%;p<0.01), R-EMDE-F (101%;p<0.01) and R-EMDM-F (368%;p<0.01), but no significant change in R-EMDE-M (25%;p=0.46). Fatigue-induced increase in EMDE-F indicated excitation-contraction coupling failure (EMDE-M) and increases in the compliance of the series elastic component (EMDM-F). Increases in R-EMDE-F were due to increases in relaxation time for the series elastic component (R-EMDM-F), but not changes in the reversal of excitation-contraction coupling (R-EMDE-M).