Musculoskeletal simulations to investigate influences of muscle weakness and sensory noise to postural control with high stiffness

When elderly and young people are compared, strategy shift from ankle strategy to hip strategy occurs at smaller perturbations in the elderly. Although understanding of how the changes of humans’ body accompanying with aging cause the difference is important, experiments only are insufficient to understand it. A simulation study reported that sensory noise increase could explain the difference, but a torque-driven model was used and internal forces which contribute to postural control were not considered. The purpose of this study was to elucidate what is the main cause of the difference in strategy shift between young and elderly considering internal forces. We executed musculoskeletal simulations of postural control against a perturbation changing the conditions of muscle and sensory functions. We utilized a neural controller model with feedback control based on proprioceptive information and translated the support surface backward as a perturbation. The magnitude of internal forces was fixed to focus on postural control with high stiffness. 9 conditions (33)()