Reliability and Validity of Electronic Measures of Balance and Gaze Control in People with Peripheral Vestibular Hypofunction

The purpose of this study was to assess the reliability and validity of a new computerized method of assessing balance and gaze control under a broad range of physical and visual conditions in people with vestibular hypofunction. Test retest reliability for balance performance as measured by COP excursion was good in all conditions with ICCs ranging from .64 to .90 in the AP and ML directions. Closed loop visual tracking as measured by COD had high reliability on the sponge and treadmill (ICC=.71-.75) as compared to open loop tracking (ICC=.325-.463) which was poor. Convergent validity showed poor correlation between clinical tests and the electronic balance and gaze assessments. Construct validity demonstrated that as physical and visual loads increased, balance performance decreased significantly on the sponge as measured by an increase in COP excursion and visual tracking performance decreased significantly on the treadmill as measured by a decrease in COD.