Reliability of four simple, quantitative tests of balance and mobility in healthy elderly females

Four common tests of balance and mobility were administered to 45 healthy women, aged 55-71 years: Sharpened Romberg (also defined as tandem stance), eyes open and closed; One-Legged Stance Test, eyes open and closed; Functional Reach; and Sit-To-Stand test. Two independent observers scored the tests, which were performed on two successive days. Inter-rater (IRR) and test-retest reliability (TRR) were good. Across the six different tests, Intraclass Correlation Coefficients ranged from 0.95 to 0.99 for scoring consistency between raters, and from 0.73 to 0.93 within raters. This is in line with previous findings based on similar subjects and similar, though not identical, testing procedures. Intercorrelations between the scores were moderate: r coefficients ranged 0.40-0.66. The results suggest that this simple test battery provides reliable scores, and that the different tests relate to a homogeneous construct, while not being redundant. It thus seems worthwhile to further investigate whether they represent and measure a unidimensional domain, rather than conceptually different dimensions, in view of achieving a unique measure of balance performance.