Entrainment to mechanical perturbations with a finite basin.

<p>Stride period is plotted as a function of stride number; (a) shows entrained gaits, and (b) shows gaits that failed to entrain. For entrained gaits, the stride period converged to the perturbation period, <i>τ</i>_p, whereas stride period continued to fluctuate when gait was not entrained. Note that the model shows a narrow basin of entrainment. Any perturbation with <i>τ</i>_p>2<i>τ</i>₀ or <i>τ</i>_p≤2<i>τ</i>₀−80 (ms) did not entrain the model.