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Muscle conduction velocity, surface electromyography variables, and echo intensity during concentric and eccentric fatigue
Author(s) -
GonzalezIzal Miriam,
Cadore Eduardo Lusa,
Izquierdo Mikel
Publication year - 2014
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.23926
Subject(s) - electromyography , eccentric , concentric , muscle fatigue , sarcolemma , nerve conduction velocity , blood lactate , medicine , intensity (physics) , anatomy , compound muscle action potential , cardiology , chemistry , electrophysiology , physical medicine and rehabilitation , heart rate , skeletal muscle , mathematics , blood pressure , physics , geometry , quantum mechanics
: Concentric (CON) and eccentric (ECC) contractions may involve different mechanisms related to changes in sarcolemma status and the consequent alteration of action potential transmission along muscle fibers. Methods : Muscle conduction velocity (CV), surface electromyography signal (sEMG), muscle quality, and blood lactate concentrations were analyzed during CON and ECC actions. Results : Compared with ECC, the CON protocol resulted in greater muscle force losses, blood lactate concentrations, and changes in sEMG parameters. Similar reductions in CV were detected in both protocols. Higher echo intensity values were observed 2 days after ECC due to greater muscle damage. Conclusions : The effects of the muscle damage produced by ECC exercise on the transmission of action potentials along muscle fibers (measured as the CV) may be comparable with the effects of hydrogen accumulation produced by CON exercise (related to greater lactate concentrations), which causes greater force loss and change in other sEMG variables during CON than during ECC actions. Muscle Nerve 49 :389–397, 2014