I. Introduction
Surface electromyography (sEMG) is a superimposed electrical signal formed by the motor unit action potential (MUAP) of a motor-associated muscle on the surface of the human skin. The sEMG is activated when a neuron with motor intention information is transmitted to the corresponding muscle, which directly reflects the body’s motor intention and the state of muscle contraction [1]. Information such as muscle contraction forces and joint moments can be decoded from the sEMG. sEMG is simple to acquire compared to Intramuscular EMG (iEMG). It offers the advantages of nonintrusiveness, security, portability, and natural identification without disturbing movement. Therefore, sEMG is not only widely used in biomechanical studies [2], [3], [4], such as human posture classification [5], [6] and motion estimation [7], [8], [9], but commercial wearable devices [10], [11] based on sEMG are being extended to a broader group of nondisabled consumers. sEMG near the forearm and wrist are beneficial for various industrial or commercial applications [12], [13], [14].