Biomechanical Foundations of Using the Y-Test for Assessing Dynamic Postural Stability in the Design of Health-Saving Technologies

Abstract

Abstract. In the modern scientific discourse of health preservation, kinesiology, and biomechanics, there is a paradigmatic shift in focus from static anthropometric characteristics to the dynamic assessment of movement strategies that determine postural stability and functional resilience of the organism. Dynamic postural stability is considered not only as an integral marker of the current functional state but also as a prognostic indicator of the risk of lower limb trauma and the formation of pathological motor behavior patterns. The aim of the article is to provide a theoretical and methodological explication of the Y-test potential as a prognostic tool in the modeling system of health-saving technologies. Methods. The study was implemented using a comprehensive interdisciplinary approach integrating systemic-structural analysis, biomechanical modeling, and mathematical-statistical data processing. Theoretical-comparative analysis and retrospective content monitoring allowed for the clarification of the conceptual apparatus of dynamic postural stability as a hierarchical system of neuromuscular control, determined by the interaction of vestibular, proprioceptive, and visual afferentation. The empirical tool was the modified Y-Balance Test (YBT) for assessing the functional resource of the lower limbs; data processing was performed using variational statistics methods. The study was conducted in accordance with the Declaration of Helsinki, with voluntary written consent from participants and full data anonymization. Results. The foot acts not only as a static support but as an active link in sensorimotor integration, essential for maintaining postural stability during dynamic interaction with the supporting surface. Structural anomalies of the foot limit coordination precision and overall locomotor performance in children. Analysis of the Y-Balance Test showed a gradual increase in movement amplitude at the ages of 7–10 years, with maximum values in the posterolateral and posteromedial directions. Age-related changes were generally statistically insignificant (p > 0.05), indicating ongoing neurophysiological maturation of proprioceptive control. Heterochrony of dynamic stability depending on sex was revealed, most pronounced at 9 years of age (p < 0.05). By the age of 10, the indices converge, maintaining differences primarily in the anterior direction, which indicates the stabilization of postural strategies at the end of primary school age. Conclusions. The Y-test allows for the effective assessment of dynamic postural stability in primary school-aged children, demonstrating the gradual maturation of proprioceptive control and revealing sexual dimorphism in the development of stabilization strategies. The results emphasize the importance of integrating instrumental biomechanical methods for the early diagnosis of motor pattern disorders and the formation of effective health-saving technologies.