Fig. 9

Kinetic trajectories of the hip, knee, and ankle. Depicted are the kinetic 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 normal stride and extended accordingly. The unperturbed stride shown is the average of 25 strides prior to the perturbation. For the hip and knee, positive moments indicate flexion moments and negative moments indicate extension moments. For the ankle, positive moments indicate dorsiflexion moments and negative moments indicate plantarflexion moments. Moments are reported in Newton-meters