To explore if ground reaction force (GRF), a widely used biomechanical parameter, can be used to identify biological problems - the impact of a temporary dysfunction caused by vestibular stimulation (VS) on everyday activities such as walking.
This study involved twenty healthy young adults. A mechanical vibrator was mounted on each side of the mastoid process in order to disrupt the vestibular system temporarily either unilaterally or bilaterally during walking. The dependent variables were the peaks of GRFs and respective variabilities in anterior-posterior (AP), medial-lateral (ML), and vertical directions (V). Each dependent variable was tested using one-way repeated ANOVA measure if the data were normally distributed. A Bonferroni correction was performed for post hoc multiple comparison.
A significant effect of VS was found in the peaks in the AP (F2, 38 = 20.607, p 0.001) and in the ML directions (F2, 38 = 20.607, p 0.001) during the weight acceptance period. In the AP direction, post hoc comparisons revealed that bilateral VS reduced GRFs more than no VS (p = 0.001) and unilateral VS (p = 0.002). The application of unilateral VS, however, increased GRFs in the ML direction when compared with the application of no VS (p = 0.001) or bilateral VS (p = 0.024).
Different types of vestibular stimulation induce different response of ground reaction force during walking, especially in the anterior-posterior and medial-lateral directions.
As a widely used biomechanics parameter, GRF measures can be applied to identify subtle changes in gait caused by VS, and this may be useful in identifying VDs in the future.
ground reaction force
variability
