The vestibular sensory plays an important role in coordinated movement of postural stability; however, there have been few studies evaluating the vestibular function related to standing postural stability. The purposes of this study were to clarify the relationship between the modified Clinical Test of Sensory Interaction and Balance (mCTSIB) and the Galvanic Body Sway Test (GBST), and to quantitatively evaluate whether aging would have synergic effects on mCTSIB and GBST among healthy subjects. Forty-four healthy subjects underwent the mCTSIB and the GBST to examine the vestibular information related to standing postural control function. There were no significant differences between the mCTSIB and the GBST. Aging showed no significant correlated with the mCTSIB; however, aging was significantly correlated with the sway velocity in GBST (ρ = －0.413, p = 0.005). The GBST was used to assess the vestibulo-spinal reflex (VSR). This study suggested that aging might diminish the VSR function by the middle-age.
