THE EFFECTS OF FATIGUE AND VISUAL PERTURBATION ON POSTURAL CONTROL IN HEALTHY POPULATIONS

Abstract

The sensorimotor system is crucial in maintaining postural control. This study looked at it. Many studies have looked at how muscular fatigue and visual perturbation affect the sensorimotor system using a force plate to collect center of pressure (CoP) data. This study sought to look at the combined effects of fatigue and visual perturbation using virtual reality (VR) to evaluate changes in non-linear CoP measures using Novel Pedar technology. CoP data was collected for six healthy young adults using a Bertec force plate and the Novel Pedar X insole pressure system in quiet stance. This was done in a non-VR condition (NVR) and a VR condition (YVR) where participants were placed into a moving room. These measures were taken before and after a muscular fatigue task that involved walking on a treadmill at a gradually increasing incline. Sum of CoP path, 95% ellipse area (EA), virtual time-to-contact (VTC) minima, and VTC minima coefficient of variation (VTC min COV) were taken and compared for pre- and post-fatigue, NVR and YVR, and the interaction between the two. Results showed a significant decrease VTC min COV (p < 0.05) as a result of fatigue. The YVR condition was able to create a significant increase in the sum of CoP path and VTC min. When looking at the interactions, it was determined that fatigue increased the VTC min for the NVR condition and decreased it for the YVR condition. It also showed a significant increase in the sum of CoP path, given pre- and post-fatigue. The results showed that both fatigue and visual perturbation created a change in postural control that increased CoP movement but allowed it to be more controlled. The force plate and Pedar data varied greatly, and usually only one collection technique detected significant differences between the main effects. Overall, gave varying results on how they affected postural control.