Abstract
A stochastic explanation is provided to investigate how human subjects maximize robustness of their balance control while exhibiting on-off intermittent behavior. To this end, the human balance control is modeled by an inverted pendulum with random delayed state feedback. Stochastic analysis based on Lyapunov exponents demonstrates that the on-off intermittency can arise under a neutrally stable condition. Furthermore, the frequency response of statistical moments is derived to show that the neutrally stable condition can be caused by a trade-off between maximal robustness and minimal phase-shift from the disturbance to the second moments.
