Beyond the Stopwatch: Associations of Sit-to-Stand Power Equations Versus Time with Balance Performance in Older Adults

Aims To compare the predictive value of STS time and equation-derived muscle power metrics (absolute, relative, allometric) for balance and fall risk in older adults.Methods In this cross-sectional study, 28 nursing home residents completed the five-times sit-to-stand (5-STS), Timed Up and Go (TUG), Functional Reach (FRT), One-Leg Stand (OLS), and Tandem Stance (TS) tests, plus a standardized fall risk questionnaire. STS power was calculated using established equations.Results Twenty-eight nursing home residents were included in the study, with a median age of 73 years; 24 participants were male (85.71%). Power metrics showed stronger predictive utility than 5-STS time for static balance and subjective fall risk outcomes. Relative power showed the strongest associations (TUG r = −.834, p < .001; OLS r = .440, p = .019; FRQ r = −.420, p = .026). After adjustment, relative (β = .506, p = .015) and allometric power (β = .436, p = .035) remained significant predictors of static balance.Conclusions STS muscle power equations, particularly relative muscle power, may provide a more meaningful alternative to 5-STS time for explaining balance performance and self-reported fall risk in older adults, supporting the integration of normalized muscle power estimates into clinical assessment.