Fig. 6

Kinematic trajectories of the hip, knee, and ankle. Depicted are the kinematic trajectories of the ipsilateral and contralateral limbs during an elevating, lowering, and delayed lowering strategy from a single subject. The trajectories were normalized to the toe-off of the unperturbed stride and extended accordingly. The unperturbed stride shown is the average of 25 strides prior to the perturbation. For the hip and knee, positive angles indicate joint flexion and negative angles indicate joint extension. For the ankle, positive angles indicate dorsiflexion and negative angles indicate plantarflexion. Angles are reported in degrees