Effect of medio-lateral vibration magnitude and frequency on the cognitive response and spatiotemporal gait parameters

Exposure to foot-transmitted vibration (FTV) in transportation industry could lead to altered locomotion and reaction times, leading to an increased risk of accidents. This research evaluates the effects of medio-lateral FTV on cognitive performance and spatiotemporal parameters during walking on a treadmill. The effect of twenty-eight combinations of sinusoidal frequencies (ranging between 0.2-8 Hz) and magnitudes (ranging between 0.05-0.1 m/s) was investigated with ten young male subjects (26 ± 1.4 years). Participants performed the Brief-Psychomotor Vigilance Task (B-PVT) test to record the reaction times (RTs) to a visual stimulus in standing posture, while walking, and in the presence of FTV. Spatiotemporal gait parameters were also obtained with the use of an Azure Kinect DK (Microsoft ©). The results showed that the vibration magnitude affects the participants' responsiveness and increases RTs. Significant differences in PVT metrics were found by comparing standing and walking trials with and without FTV exposure. The frequency factor influences gait parameters with an increase in the stride time and the step width at 1-2 Hz. These findings suggest that the vigilance and the gait pattern may be negatively affected by exposure to medio-lateral FTV.