Quantification of Sensory Information in Human Balance Control

A human balance control model is developed, which includes the different sensory systems as well as neural time delays. The model is based on optimal control theory. Platform perturbation experiments were done to quantify the precision of the different sensory systems by matching model predictions with experimental results. The precision of the sensors was quantified by the variances of sensor noise. The noise to signal ratios for the muscle spindles are 3-7% and for vision 11-14%. For the vestibular organs unambiguous noise to signal ratios could not be found. To find the noise to signal ratios of the vestibular organs the method of identification of sensory information has to be modified.