Comparison of the experimental (mean ± 1 s.d.) and simulation peak ankle (plantar flexion) and knee (flexion) joint angular velocities during the propulsion phase as walking speed increased from 60 to 120% PTS. In both joints, the experimental velocities systematically increased with walking speed, except for the slight decrease in the ankle velocity at 120% PTS. At all speeds, the corresponding simulation ankle velocities were lower than the experimental data, while the knee velocities were slightly higher except at 120% PTS.