DIFFERENCES BETWEEN CONCENTRIC AND ECCENTRIC CONTRACTION INDUCED MUSCLE FATIGUE

Abstract

Studies of neuromuscular activation often evaluated through isometric contractions. However, this type of contraction may not truly represent muscle actions during activities. EMG analysis is not only used to determine motor unit activations, but also used to determine muscle conduction velocity by transforming signals into frequency spectrum. Studies have shown that fatigue mucles produced a relativly slower conduction velocity measured by mean power frequency (MPF). Therefore, the purpose of this study was to compare the effects of muscle fatigue generated by two different types of contraction. We hypothesized that muscle fatigue generated by concentric contractions (CC) would cause gretaer muscle contraction frequency reduction than eccentric contractions (EC).