Anticipatory postural adjustments during step initiation: Elicitation by auditory stimulation of differing intensities

► Step initiation is associated with anticipatory postural adjustments (APAs). ► APAs can be triggered by startling stimuli (suggesting the involvement of midbrain structures). ► Non-startling stimuli can also evoke APAs. ► The louder the stimulus, the more frequent the elicitation. ► The brainstem is not necessarily the prime mover in the release of these long-latency APAs.