Objectives: To evaluate the relationships between physiological variables and balance and the potential predictors of static and dynamic balance in young (n = 30, 18-25 years), middle-aged (n = 26, 35-45 years), and late middle-aged (n = 29, 55-64 years) women. Methods: Maximal leg strength, hip and ankle flexibility, total and regional body composition, and total and regional bone mineral density were measured. The NeuroCom Balance Master (NeuroCom International, Inc, Clackamas, Oregon) assessed static postural stability (Modified Clinical Test of Sensory Interaction on Balance [MCTSIB], eyes open [EO] on foam; Unilateral Stance [US] eyes open and eyes closed [EC]) and dynamic balance (Tandem Walk [TW] and Step Quick and Turn [SQT]). Results: The youngest group was significantly stronger (P = .001), had greater bone mineral density (P = .001-.028), lower percentage of fat (P = .001), and greater bone-free lean body mass (P = .028 for arms and P = .004 for legs) than the older groups. Hip and ankle flexibility was similar between groups and only 2 measures of balance (US EO and SQT) were significantly different, with the oldest group being significantly less stable than the other 2 groups (P = .001 and P = .018, respectively). Regression analyses determined only 1 significant prediction equation for balance for the youngest group (TW Sway Velocity), 2 significant prediction equations for the middle-aged group (US EC Sway Velocity and SQT Sway), and 5 significant prediction equations for the oldest group (MCTSIB EC Sway Velocity, US EO Sway Velocity, US EC Sway Velocity, TW Sway Velocity, and SQT Sway). Conclusion: Measures of balance were easier to predict as age increased, and there were more significant correlations between predictors of balance when balance was assessed dynamically (TW and SQT) rather than statically (MCTSIB and US).
