Development of Dynamic Posture Keeping Training Device for Maintenance of Antigravity Muscles in a Microgravity Environment - Validation of Training Effects Based on a 2DOF Kinetic Model Considering Lumbar Flexion-

In recent years, manned bases have begun to make extended stays in space and on other planets. Medical problems such as bone and muscle loss have been observed during long stays in space, and training equipment has been developed for use in space to improve these problems. In this study, we proposed a dynamic training method to maintain anti-gravity muscles under microgravity environment, aiming at the application to the long-duration stay in space including exploration of other planets. The training method focused on the function of antigravity muscles. This device is designed to activate the subject's antigravity muscles and achieve antigravity muscle maintenance in a microgravity environment by causing disturbance and instability in the subject's posture and making the subject conscious of maintaining an upright posture. In a previous study, we proposed a static training method to maintain posture in an anterior and posterior leaning posture. Therefore, this paper proposes a dynamic antigravity muscle training method that tilts forward and backward, and posture maintenance experiments were conducted using a prototype machine to realize this method. The target movements are dynamic holding of forward and backward leaning postures. The EMG potentials of each muscle were measured and compared during the experimental movements in the static posture holding evaluation test conducted in the previous study. The results showed that the proposed method was superior as a training effect because the muscle activity of the gluteus maximus and rectus femoris muscles increased approximately 10-fold compared to the muscle potential results of previous studies.