Are bioelectrical parameters and functionality associated with postural control in the elderly?

Background: Alterations in bioimpedance parameters and postural control occur with aging and contribute to the increased risk of falls. The aim of this study was to evaluate the balance behavior in relation to bioimpedance and functionality. Methods: We evaluated 21 elderly (men: 77.3 ± 9.5 years; women: 74.2 ± 9.6 years). The balance in standing posture was measured by the movement of the pressure center in seven positions. Bioimpedance was defined by its parameters resistance, reactance and phase angle, and functionality through the Timed Up and Go Test and Short Physical Performance Battery. Findings: In the analysis of the mediolateral velocity at the positions feet separated with open and closed eyes, feet together with eyes closed and semi-tandem with eyes open on the platform, an inverse correlation between balance and bioimpedance variables were verified for all models, with a coefficient of determination varying between 20% and 74%. Inverse and significant correlations between reactance and phase angle in the one-legged-support position were verified, in all adjustment models, with coefficient of determination varying between 62% and 91%. In the analysis of mediolateral velocity for the semi-tandem eyes closed position, positive correlation with TUG and an inverse correlation with bioimpedance parameters and pennation angle were observed, with coefficient of determination varying between 21% and 67%. Interpretation: The postural control is linearly related to bioimpedance parameters and functionality in the elderly. The assessment of balance can provide important information and furnishes useful insights for prevention and treatment strategies in elderly.