A Wii Balance Board can capture changes in postural dynamics resulting from task manipulations during standing

Postural sway dynamics has been shown to characterize healthy and pathological systems, but obtaining such measurements outside of a laboratory setting is not simple. This is because portable laboratory-grade force platforms are expensive. A previous study showed that a portable device, the Nintendo Wii Balance Board (WBB), obtained similar measures of postural sway compared to a force platform. However, it is currently unknown whether the WBB can accurately measure changes in the persistence of postural sway, specifically through center of pressure velocity (COPv) measurements. Therefore, the purpose of this study is to compare the accuracy of measures in persistence of postural sway (quantified by detrended fluctuation analysis [DFA]) of COPv obtained between a Wii Balance Board and a force platform. Healthy young participants performed three different conditions: quiet standing on both legs with eyes open, quiet standing on both legs with eyes closed and standing on one leg with eyes open. From the COP displacement data, COPv was calculated for the WBB and FP. DFA was used to analyze the persistence and anti-persistence characteristics of the COPv in anterior-posterior and mediolateral directions. Additionally, the following variables were measured: Root-mean-square, sway path, and sway range. To test the similarity between the two devices, two-way mixed absolute agreement intraclass correlation, also referred to as Intra Class Correlation was calculated between the WBB and FP at both sampling rates for DFA and secondary measures. The level of statistical significance was set at p \u3c 0.05