Effects of the ankle angle of an ankle foot orthosis on foot pressure during the gait in healthy adults

[Purpose] The purpose of this study was to investigate the effects of the ankle angle of an ankle foot orthosis (AFO) on foot pressure during the gait in healthy adults. [Subjects] Sixteen healthy males with neither orthopedic nor neurological problems participated in this study. [Methods] Subjects walked on a walkway at a self-selected pace with an AFO set at four different ankle angles (-5°, 0°, 5°, and 10°). Foot pressure was measured randomly according to the ankle angle of the AFO using an F-scan system. Three trials were measured and averaged for data analysis. [Results] The peak foot pressure of the hallux, 2nd-5th toes, 2nd and 3rd metatarsal heads, 4th and 5th metatarsal heads, and the heel showed significant differences among the AFO ankle angles: angles of 0° and -5° increased the foot pressure of the lateral legions, and the peak foot pressure of the heel at an AFO ankle angle of 10° was significantly greater than those of the other angles. [Conclusion] The ankle angle of the AFO affected foot pressure and gait patterns during gait. The results suggest that the appropriate angle for an AFO is between 5° and 10° when AFOs are prescribed by clinicians.