TY - JOUR
T1 - Torque and mechanomyogram correlations during muscle relaxation
T2 - Effects of fatigue and time-course of recovery
AU - Cè, Emiliano
AU - Rampichini, Susanna
AU - Limonta, Eloisa
AU - Esposito, Fabio
PY - 2013/12
Y1 - 2013/12
N2 - To assess the validity and reliability of the mechanomyogram (MMG) as a tool to investigate the fatigue-induced changes in the muscle during relaxation, the torque and MMG signals from the gastrocnemius medialis muscle of 23 participants were recorded during tetanic electrically-elicited contractions before and immediately after fatigue, as well as at min 2 and 7 of recovery. The peak torque (pT), contraction time (CT) and relaxation time (RT), and the acceleration of force development (d2RFD) and relaxation (d2RFR) were calculated. The slope and τ of force relaxation were also determined. MMG peak-to-peak was assessed during contraction (MMG p-p) and relaxation (R-MMG p-p). After fatigue, pT, d2RFD, d2RFR, slope, MMG p-p and R-MMG p-p decreased significantly, while CT, RT and τ increased (P<0.05 for all comparisons), remaining altered throughout the entire recovery period. R-MMG p-p correlated with pT, MMG p-p, slope, τ and d2RFR both before and after fatigue. Reliability measurements always ranged from high to very high. In conclusion, MMG may represent a valid and reliable index to monitor the fatigue-induced changes in muscle mechanical behavior, and could be therefore considered an effective alternative to the force signal, also during relaxation.
AB - To assess the validity and reliability of the mechanomyogram (MMG) as a tool to investigate the fatigue-induced changes in the muscle during relaxation, the torque and MMG signals from the gastrocnemius medialis muscle of 23 participants were recorded during tetanic electrically-elicited contractions before and immediately after fatigue, as well as at min 2 and 7 of recovery. The peak torque (pT), contraction time (CT) and relaxation time (RT), and the acceleration of force development (d2RFD) and relaxation (d2RFR) were calculated. The slope and τ of force relaxation were also determined. MMG peak-to-peak was assessed during contraction (MMG p-p) and relaxation (R-MMG p-p). After fatigue, pT, d2RFD, d2RFR, slope, MMG p-p and R-MMG p-p decreased significantly, while CT, RT and τ increased (P<0.05 for all comparisons), remaining altered throughout the entire recovery period. R-MMG p-p correlated with pT, MMG p-p, slope, τ and d2RFR both before and after fatigue. Reliability measurements always ranged from high to very high. In conclusion, MMG may represent a valid and reliable index to monitor the fatigue-induced changes in muscle mechanical behavior, and could be therefore considered an effective alternative to the force signal, also during relaxation.
KW - Force
KW - MMG
KW - Muscle relaxation
KW - Off kinetics
KW - Reliability
KW - Torque
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U2 - 10.1016/j.jelekin.2013.09.007
DO - 10.1016/j.jelekin.2013.09.007
M3 - Article
C2 - 24209873
AN - SCOPUS:84887256880
VL - 23
SP - 1295
EP - 1303
JO - Journal of Electromyography and Kinesiology
JF - Journal of Electromyography and Kinesiology
SN - 1050-6411
IS - 6
ER -