Correlation dimension estimates of human postural sway

► Ergodic theory of complex dynamical systems were applied to human postural sway. ► 5 Trials of 180-sec were performed by 28 subjects with ages of 6 to 84 years old. ► 97% of the trials or 46% of the subjects were stationary or ergodic respectively. ► Nonlinear metrics differed significantly due to aging but linear metrics did not. ► Aging affects ability of independently controlling multiple degrees of freedom.