Effects of Virtual Environmental Cues on Quiet Stance in Young Adults.

ObjectiveThe aim of this study was to explore the effect of contrast and spatial frequency intensities in a virtual environment on quiet, upright stance.BackgroundVisual feedback provides crucial sensory information to maintain postural control. Changes to contrast sensitivity and spatial frequency in the environment have been shown to influence postural stability; however, there is currently no work examining the influence of environmental contrast and spatial frequency on balance among young healthy populations.Methodology28 healthy participants stood on a force plate, feet together, while wearing a head-mounted display. Participants viewed a virtual room and were exposed to four 60s conditions, each with a modified level of contrast (low or high) and spatial frequency (low or high) of the surrounding wallpaper. Center of pressure and head displacement root mean square and mean power frequency were calculated to quantify balance behavior.ResultsHigher contrast reduced sway, particularly along the AP axis and on a foam surface (COP AP RMS foam: 7.56 ± 1.92 mm vs. 8.61 ± 1.70 mm; HMD AP RMS: 7.46 ± 2.57 mm vs. 8.92 ± 3.20 mm, mean ± SD). Spatial frequency affected only COP ML RMS on foam, with lower spatial frequencies producing slightly greater sway amplitude (7.93 ± 1.93 mm vs. 7.42 ± 1.75 mm).ConclusionIn conclusion, the level of both contrast and spatial frequency in the surrounding environment impact balance control during quiet, upright stance.ApplicationThis study suggests visual environmental cues should be considered when designing environments to reduce fall risk.