Foot sole two-point discrimination is not associated with dynamic standing balance in healthy adults

Abstract

[Purpose] To evaluate the association between foot sole two-point discrimination and dynamic standing balance. [Participants and Methods] This cross-sectional, observational study included 50 healthy adults. Participants were made to stand on a firm or foam surface with eyes open or closed, and the center of pressure length was measured for static standing balance and limits of stability for dynamic standing balance. Two-point discrimination and muscle strength were assessed using the two-point discrimination test and toe grip strength, respectively. We then analyzed the association with sensory-motor assessment and standing balance. [Results] Significant differences were observed for almost all factors between static and dynamic standing balance. Two-point discrimination was associated with static standing balance, and muscle strength was associated with dynamic standing balance on a firm floor. There was no significant association between two-point discrimination and dynamic standing balance. [Conclusion] These results indicate that foot sole two-point discrimination is not directly associated with dynamic standing balance in healthy adults. Therefore, postural stability must be evaluated considering the specific floor surfaces and sensory conditions in clinical situations, and assessment of dynamic standing balance based only on two-point discrimination should be avoided.