After walking onto a moving platform subjects experience a locomotor aftereffect (LAE), including a self-generated stumble, when walking again onto a stationary platform. Thus, this LAE affords examination of the role of vestibular input during an internally generated postural challenge. The experiments involved, walking onto the stationary sled (BEFORE trials), walking onto the moving sled (MOVING) and a second set of stationary trials (AFTER). We investigated 9 bilateral labyrinthine defective subjects (LDS) and 13 age-matched normal controls (NC) with eyes-open. We repeated the experiment in 5 NC and 5 LDS but this time the AFTER trials were performed twice, first eyes-closed and then on eye re-opening. During MOVING trials, LDS were considerably unstable thus confirming the established role of the vestibular system during externally imposed postural perturbations. During AFTER trials, both groups experienced an aftereffect with eyes-open and closed, shown as higher approach gait velocity, a forward trunk overshoot and increased leg EMG. However, there were no significant group differences due to the fact that stopping the forwards trunk overshoot was accomplished by anticipatory EMG bursts. On eye re-opening the aftereffect re-emerged, significantly larger in LDS than in NC. The lack of group differences in AFTER trials suggests that when facing internally-generated postural perturbations, as in this adaptation process, the CNS relies less on vestibular feedback and more on anticipatory mechanisms. Re-emergence of the aftereffect on eye re-opening indicates the existence of a feedforward visuo-contextual mechanism for locomotor learning, which is adaptively enhanced in the absence of vestibular function.