Research on Motion-Less VR: Comparative Evaluation of Surface EMG Signals Induced by Motion Intention Output under Body Immobilized and Normal Conditions

The authors have proposed Motion-Less VR, an immersive VR system without actual body motion. Motion-Less VR is a system that enables virtual body operation by measuring the joint torques output under body immobilization and simulating the motion that would typically occur. Our previous study developed a system to realize a 2- DOF (shoulder and elbow) operation and showed its validity. However, it has not yet achieved the same level of operational performance as that of normal, natural body motion. One of the reasons for this is the difference in posture between the real and virtual bodies. This paper investigated the effects of postural differences caused by body immobilization on muscle output, which is the source of joint torque. Specifically, we measured surface EMG (electromyography) during a motion intention output task where the participant attempted to track a target under non-visualization of the body and compared the results between the body immobilization and normal conditions. As a result of the experiment, we confirmed that the EMGs under body immobilization differed from those under normal conditions. This result suggests that the difference in posture between the physical body and the virtual body may affect the operating performance of the virtual body.