Frequency analysis of the center of pressure in tandem stance in community-dwelling elderly.

[Purpose] The present study aimed to clarify the effects of balance control on the pronation and supination movements of the talocrural joint in community-dwelling elderly women by conducting a frequency analysis of the center of pressure during tandem stance. [Subjects and Methods] The study participants were 18 subjects who maintained tandem stance for 20 s and 11 who had difficulty maintaining tandem stance for 20 s. The frequency-power spectra were computed and classified into three frequency bands. Each power spectral value was divided by the sum of the power spectral values to obtain the %power. [Results] Significant differences in high-frequency band %power value for the center of pressure in both the mediolateral and anteroposterior components were evident between the groups. [Conclusion] A markedly significant difference was observed, particularly in high frequency band %power, depending on balance control. The present findings indicated that elderly participants with diminished balance control had difficulty with rapid adjustment centered on the ankles, suggesting that rapid joint movement involving interlimb coordination centered on the ankles is required to maintain tandem stance.