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 degrees, 0 degrees, 5 degrees, and 10 degrees). 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 degrees and -5 degrees increased the foot pressure of the lateral legions, and the peak foot pressure of the heel at an AFO ankle angle of 10 degrees 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 degrees and 10 degrees when AFOs are prescribed by clinicians.