Research Progress and Prospect of Muscle Synergies Theory for Redundancy Control of Complex Human Movement

The neuromuscular system is an open complex giant system. The coordination between the central nervous system and activities of different muscles is a long-standing core scientific theoretical problem in sports neuroscience research. In the field of human motor control, redundancy control not only exits in the description of whole-body movement but also the description of local limb movement. Muscle synergies theory suggests that the nervous system can reduce the computational burden of redundancy control through modular control by recruiting several muscles simultaneously. This study retrospected the origin and basic viewpoints of muscle synergies theory, and summarized the mathematical models and basic process of muscle synergies analysis. In addition, this study focused on the application of muscle synergies theory in sports science, clinic and robot control. Although there are different views on the physiological evidence of muscle synergies theory, studies have confirmed that muscle synergies exist in vertebrate and human redundancy control systems, which can well explain the central nervous system's control mechanism of muscle activity. Future research should still focus on the exploration of modular hypothesis and mechanisms of muscle synergies by designing experimental paradigms for diverse tasks and theoretical modeling work.