Motion sickness and postural control among Danish adolescents

Easily available clinical tests to evaluate postural control are needed. Furthermore, motion sickness (MS) and postural control are correlated. The aims of this study were to compare the internal validity of a set of clinical tests of postural control with the internal validity of static posturography and to evaluate possible associations between postural control and MS.

We included healthy subjects from a primary school in Denmark who completed questionnaires about MS and underwent two rounds of clinical tests of postural control and static posturography using a Tetrax Interactive Balance System two weeks apart. For clinical tests of postural control, subjects were observed for up to 30 s standing on both legs, on one leg, on a pillow both with their eyes open and again with their eyes closed.

Twenty-one subjects were included: 71% males with an average age of 13.7 years. Agreement rates ranged from 62% to 95% between test and retest in clinical tests.; lowest for subjects standing on their non dominant leg with their eyes open and highest for subjects performing Romberg's test with their eyes closed along with subjects standing on a pillow with their eyes open. For several of these tests, almost all subjects were able to hold their balance for the full 30 s. Test-retesting using static posturography by Bland Altman plot showed datapoints scattered equally above and below the mean line indicating no systematic bias. Results of clinical tests and static posturography were not associated. MS was reported from 43% of subjects and a trend was observed with high sway scores from subjects suffering from MS. This was statistically insignificant.

Due to a ceiling effect, subjects achieved the same scores in both rounds of testing in several of the clinical tests, reducing the clinical importance of these tests. Compared to clinical tests, static posturography seemingly remains the superior method when it comes to evaluation of postural control, although not as easily applicable in a daily clinical setting. When comparing MS and postural control a trend was observed, indicating higher sway scores in subjects suffering from MS.