Exploring the Association between Postural Instability and Motion Sickness in Children and Adolescents

OBJECTIVE: Motion sickness (MS) is a common condition that may impair daily functioning in children. While Sensory Conflict Theory (SCT) explains symptom provocation, it does not fully account for individual susceptibility. The Postural Instability Theory (PIT) proposes that persistent inability to maintain postural stability precedes and predicts MS. We aim to investigate the association between MS and postural stability in children and adolescents with MS. STUDY DESIGN: Prospective case-control study. SETTING: A quaternary referral university hospital. METHODS: 40 participants (aged 5-18 years) were included. MS was defined according to Bárány Society criteria. Postural stability was assessed using the single-leg stance test (eyes open and closed), the Biodex Balance System (static and dynamic indices), and the Modified Clinical Test of Sensory Interaction and Balance (MCTSIB). Motion sickness susceptibility (MSSQ-Short) and quality of life (PedQOL) were also evaluated. Logistic regression was used to identify predictors of MS. RESULTS: Children and adolescents with MS demonstrated significantly poorer postural stability across multiple measures. In multivariable analysis, reduced eyes-closed single-leg stance performance (AOR = 0.82, P = .009) and higher MCTSIB stability index (eyes open on foam; AOR = 1.83, P = .003) independently predicted MS, with dynamic anterior-posterior sway showing borderline significance. CONCLUSION: Impaired postural control is a key determinant of MS susceptibility. Simple assessments of postural instability enable early identification of patients at risk of MS. Facilitating targeted balance rehabilitation allows a shift from symptomatic management toward prevention of MS in pediatric populations.