Evaluation of dynamic balance among community-dwelling older adult fallers: A generalizability study of the limits of stability test

Objective: To establish reliability estimates of the 75% Limits of Stabilit y(R) Test (75% LOS test) when administered to community-dwelling older adul ts with a history of falls. Design: Generalizability theory was used to estimate both the relative cont ribution of identified error sources to the total measurement error and gen eralizability coefficients. A random effects repeated-measures analysis of variance (ANOVA) was used to assess consistency of LOS test movement variab les across both days and targets. Setting: A motor control research laboratory in a university setting. Participants: Fifty community-dwelling older adults with 2 or more falls in the previous year. Main Outcome Measures: Spatial and temporal measures of dynamic balance der ived from the 75% LOS test included average movement velocity, maximum cent er of gravity (COG) excursion. end-point COG excursion, and directional con trol. Results: Estimated generalizability coefficients for 2 testing days ranged from .58 to .87. Total variance in LOS test measures attributable to incons istencies in day-to-day test performance (Day and Subject x Day facets) ran ged from 2.5% to 8.4%. The ANOVA results indicated that no significant diff erences were observed in the LOS test variables across the 2 testing days. Conclusions: The 75% LOS test administered to older adult fallers on 2 cons ecutive days provides consistent and reliable measures of dynamic balance.