GREATER EFFECT OF AUDITORY STIMULI THAN VISUAL STIMULI ON ANTICIPATORY POSTURAL ADJUSTMENTS INCREASE

Purpose: The role of visual stimuli as the primary stimulus and the effect of auditory stimulus before external perturbation on Anticipatory Postural Adjustments (APAs) releases has been investigated, but which type of stimulus (auditory or visual) before perturbation has a more significant effect on initial APAs release, needs to be investigated. So, this study aimed to investigate the role of visual-auditory contributions before external perturbation on APAs and the effect of stimulus presentation on the release of APAs at different time intervals. Methods: Participants in this study were fourteen physical education students (Meanage 22.4 +/- 2.14 years) exposed to five trials of visual stimulus and five trials of an audible stimulus (80 dB) while standing on the Biodex balance sheet. Then, 1.4 seconds after presenting the stimulus, external perturbation was applied. Electromyography (EMG) activity of the postural muscles was recorded during all trials. APAs were extracted at intervals of -100 to 50 ms (APA1), 50 to 200 ms (APA2), and 200 to 350 ms (APA3). The mixed ANOVA and repeated measures analysis of variance with Bonferroni correction test were used for data analysis. Results: The results showed that the presentation of visual and auditory stimuli increased the APAs of the postural muscles. According to these results, APA3 was greater than APA2 and APA2 than APA1(P=0.05). Also, the results showed that auditory stimulus increased the APAs of the postural muscles more than the visual stimulus (P=0.05). Conclusion: Generally, the researchers concluded that providing an auditory stimulus before perturbation has a greater effect on APA than a visual stimulus in healthy young girls. Therefore, it is suggested that in order to prevent imbalance or maintain greater balance, auditory stimuli with appropriate intensity can be used. Furthermore, subsequent research on this topic could include comparing APA release under the influence of visual and auditory stimuli in men and women, athletes and non-athletes, and healthy individuals with individuals with mobility impairments.