ABSTRACT
BACKGROUND: Different types of foot orthoses have been prescribed for patients with flatfoot. Results of several studies have shown that orthoses were able to change balance parameters in people with flatfoot. However, the possible effect of orthosis flexibility on balance has not yet been investigated. OBJECTIVES: The aim of the current study was to investigate the immediate effect of a rigid University of California Berkeley Laboratory (UCBL) foot orthosis, a modified foot orthosis, and a normal shoe on the postural sway of people with flexible flatfoot. STUDY DESIGN: Quasi-experimental. METHODS: In all, 20 young adults with flatfoot (aged 23.5 ± 2.8 years) were invited to participate in this study. The Biodex Stability System was employed to perform standing balance tests under three testing conditions, namely, shoe only, UCBL, and modified foot orthosis. Total, medial-lateral, and anterior-posterior sway were evaluated for each condition. RESULTS: The results of this study revealed no statistical difference in the medial-lateral and anterior-posterior stability indices between foot orthoses and shoed conditions. The overall stability index with the UCBL foot orthosis, however, was significantly lower than that with the modified foot orthosis. CONCLUSION: The UCBL foot orthosis was able to decrease total sway and improve balance in people with flexible flatfoot. CLINICAL RELEVANCE: Results of previous studies have indicated that foot orthoses were able to affect the balance of people with flatfeet. However, the possible effects of flexible orthoses on balance have not been examined. The results of this study may provide new insight into material selection for those people with balance disorders.
