Accuracy of force and center of pressure measures of the Wii Balance Board
Bartlett HL, Ting LH, Bingham JT. Gait & Posture. 2013 August 1. [Epub ahead of print]
Take Home Message: The Wii Balance Board (WBB) cannot be used as a substitute for laboratory-grade force plates due to lower accuracy and precision measurements. Its affordability make it a popular choice so the WBB may be appropriate in scenarios where lower accuracy and precision are acceptable.
The Nintendo Wii Balance Board (WBB) offers a more affordable method of assessing postural control as compared to lab-grade force plates. It can provide ground reaction forces and center of pressure (COP) measures while a person stands or moves on the platform. However, it is unclear as to how appropriate the WBB is for measuring balance control, as the accuracy and reliability of force and COP measures for the product are uncertain. Therefore, Bartlett et al. evaluated the uncertainty metrics for static loads on the WBB so that it may be evaluated as an appropriate or inappropriate tool for balance measurement in humans. Specifically, this study determined the accuracy and repeatability of the measures. The authors evaluated nine WBBs and one laboratory-grade force plate. Of the nine WBBs, three were considered lightly used and six were considered heavily used. Bartlett et al validated the force and COP measures for each instrument by using calibrated masses to calculate a standard measurement uncertainty analysis, which assesses accuracy and repeatability. The authors found that the uncertainty of force and COP measurements among WBB were much higher than those recommended for posturography applications but the repeatability measures within the same board were better than across different boards. The measurements between lightly-used and heavily-used WBBs were not different.
Overall, the data from this study suggest that the WBB should not be used as a substitute for laboratory-grade force plates. However, these boards may be sufficient in measuring postural sway when changes or differences greater than 10mm are anticipated, but further validation still needs to be completed. If clinicians decide to incorporate a WBB into their practice the results suggest that we should use one WBB rather than multiple WBBs. It was also reassuring that lightly- and heavily-used boards performed similarly, which revealed these systems are durable. While the WBB is not a substitute for expensive force plates, it can still be used as a part of a rehabilitation program to improve balance and coordination as well as in scenarios where lower accuracy and precision are acceptable.
Questions for Discussion: Have you used WBBs to measure balance control in patients? Does the affordability of the WBB outweigh its lack of accuracy?
Written by: Laura Marley
Reviewed by: Lisa Chinn and Jeffrey Driban
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Bartlett HL, Ting LH, & Bingham JT (2013). Accuracy of force and center of pressure measures of the Wii Balance Board. Gait & Posture PMID: 23910725