Physiological Based Motor Control of Postural Balance

Postural balance has been studied using mathematical models and experimental studies for a long time. Physiology based postural balance involves the skeletal muscles as actuators, which are innervated by the central nervous system through a motor control signal to maintain a stable posture or to have a stable prescribed movement. In physiology the neural feedback is provided by the proprioceptive and vestibular sensors. In this study we focus on the physiological model of skeletal muscle, muscle spindle and Golgi tendon organ (proprioceptive) along with semicircular canal and otolith organ (vestibular) system. The central nervous controller is modeled by linear quadratic regulator and linear quadratic Gaussian methods for generating control signal to the muscles. The musculoskeletal-sensory model under consideration is restricted to sagittal plane only. Our computer simulation results demonstrate that for a small movement over the base of support (BoS) a major contribution toward postural balance comes from the Golgi tendon organ. Simulation results also shows that under noisy conditions presence of all sensors becomes mandatory for attaining postural balance.