Frequency and velocity of rotational head perturbations during locomotion

The magnetic searth coil technique was used to record horizontal (yaw) and vertical (pitch) head rotations of 20 normal subjects during walking in place, running in place, vigorous voluntary horizontal head rotation, and vigorous voluntary vertical head rotation. Data are presented to show that (1) during locomotion, the head is stabilized in space incompletely but adequately so that the vestibuloocular reflex (VOR) is not saturated; (2) durign vigorous, voluntary head rotations, the maximum head velocity exceeds the range where the VOR can stabilize gaze; and (3) the frequencies of head rotations that occur during locomotion greatly exceed frequencies conventionally used in the laboratory for testing the VOR.