The purpose of this study is compare the static standing balance with wearing or non-wearing of Hinged Plastic Ankle Foot Orthosis(HPAFO) case for normal adults before the application of ankle foot orthosis is made to patients. Sixteen normal adults living in Gimhae city were studied and it was done from 11th February 2008 to 29th February 2008. TETRAX was used to compare static standing balance ability. Static standing balance ability was assessed with 8 ways of test poses by Fourier Harmony Index which indicates body sway and fall index which indicates stability and the results are as follows. Firstly, as a result of comparing Fourier Harmony Index in a condition of standing pose, there was no significant difference in the fact that static standing balance ability of the before and after wearing of HPAFO was influenced by visual sense, somatic sensation, vestibular system input. Secondly, in comparison with fall index with wearing or non-wearing of HPAFO, the average of fall index was 23.63±11.80 in the condition in which the orthoses were not worn. On the other hand,when the orthoses got worn, the average of fall index was 35.16±11.07 and there was significant difference(p<.05). It means that the stability of a normal adult wearing HPAFO goes down rather than that in case of non wearing. Effects of using period of orthosis to the balance abilities on patients should be conducted in the future.