Tendency of Characteristic Change by Electrical Agonist-Antagonist Muscle Sum When Using a Human Neuromuscular System Identification Method

In recent years, attempts have been made to develop human digital twins of the locomotorium for biomechanical simulations, highlighting the need for methods to capture these dynamics. Our group has proposed a simple method using functional electrical stimulation that emphasizes coordination among multiple muscles. This method uses the ratio and sum of the electrical stimulation intensities applied to the extensor and flexor muscles—known as the electrical agonist-antagonist muscle (EAA) ratio and EAA sum, respectively. By relating the force induced by electrical stimulation to the EAA ratio, we can capture the dynamics of the human neuromuscular system (NMS). In this study, we investigated how change in the EAA sum influence NMS dynamics.