抄録
AIM: We investigated the differences in the occurrence of muscle fatigue depending on the contraction type and relationship between muscle fatigue and strength improvement with surface EMG (SEMG). In practice, for short-term resistance training, we studied a personally customized process for individuals. PROTOCOL: Sixteen healthy male subjects (21-23 yr-old) participated in this research. Squat exercise was preformed two times per week for six consecutive weeks. A one-day session consisted of three sets of 12 strokes. We measured the knee joint angle (KJA) with a flexibility goniometer and the muscle activity of the vastus lateralis with SEMG in each stroke of the squat exercise. Each stroke was divided into concentric and eccentric contractions referring to the KJA. SEMGs were evaluated using the average rectified value (ARV) and mean power frequency (MPF). RESULTS: For the eccentric contraction, muscular strength increased regardless of muscle fatigue. However, increasing muscular strength (r=0.49, p<0.10) correlated with the ratio of muscle fatigue occurrence for the concentric contraction. Focusing on the concentric contraction, we devised a personally customized process with the time-varying behavior of muscle fatigue. As a result, muscular strength improvement could be effectively evaluated using SEMGs.
