EFFECT OF REPETITIVE HOPPING ON POSTURAL BALANCE IN YOUNG ADOLESCENT WITH FLEXIBLE FLATFOOT

Abstract

The flexible flatfoot was a common problem in every age. Medial longitudinal arch had high development in adolescence and slight development in adult. Flexible flatfoot can disturb some of functional performance especially weight bearing performance during standing balance. Therefore, adolescent who have flexible flatfoot should acquire appropriate treatments for protecting of balance impairment and joint injuries in the future. Objective: The study compared navicular drop and postural stability via single leg standing before and after repetitive hopping in normal foot and flexible flatfoot. Methodology: Participants had age between 13 and14 years old. They were separated in groups of flexible flatfoot and normal foot. Participants were measured navicular drop and single leg standing before and after repetitive hopping. Wilcoxon Signed-Rank test and The Mann-Whitney U test were statistical analysis for calculating of difference within and between groups of normal and flexible flatfoot. Result: The result of navicular drop and single leg standing during eyes open showed significant difference between groups of normal and flexible flatfoot. After repetitive hopping, increasing of navicular drop was shown in both groups and flexible flatfoot found significant reduction of balance ability through single leg standing with eyes open. The result might be explained as muscular fatigue after repetitive hopping lead to changing of supporting structure under the medial longitudinal arch, changing of joint alignment, and changing of weight distribution on plantar foot. Nevertheless, there were no difference obviously in conditions of single leg standing with eyes closed or foam surface. The results may imply that adolescent have immaturity of sensory systems and they have reliance on visual system for balance stability. Therefore, study of standing balance in adults after repetitive activity with weight baring will be a suggestion for further study. Adolescent who have flexible flatfoot should acquire earlier treatment for preventing of risk factors in the future.