In this work, isometric contraction of triceps brachii muscles are analyzed using surface electromyography (sEMG) signals and multifractals. The signals are recorded from 20 healthy adult volunteers at three different angles of elbow flexions namely 30º, 60º and 90º using standard experimental protocol. The recorded signals are preprocessed and subjected to Multifractal Detrended Fluctuation Analysis (MF-DFA). The three extracted MF-DFA features namely, peak exponent event, rare exponent event and smooth exponent event, are used for further analysis. The results show that multifractal spectrum response are distinct for all the three angles of flexion. It is observed that multifractal spectrum is shifting from higher order exponents to lower order with the increase in the angle of flexion. The features are statistically highly significant between 30º and 90º flexion. The smooth exponent is found to be statistically highly significant for both 60º-90º and 30º-90º flexion. It appears that this method of multifractal technique is an useful approach to understand muscle contractions in fatigue and in varied clinical conditions.