Correlations between muscular contraction type and muscle electrical activity

Each activated motor unit produces an electrical signal. By summing the signals produced at the level of each activated motor unit we achieve an electrical signal that can be recorded as electrical waves. In this study we aimed to identify a correlation between different types of muscular contractions and the muscle electrical activity. 23 healthy persons aged between 19 and 52 years participated to this study. By recording the electrical activity of the triceps brachialis muscle during its contraction it has been found that the strongest electrical activity of the muscle was produced during isometric contractions, followed by eccentric contraction, contraction with weight in the hand, contraction against gravity and contraction without gravity. In other words, as the muscle load is higher the muscle electrical activity is more intense.