Normative Values and Measurement Properties of the Bed Bridge Test.

Abstract

To establish normative values and develop reference equations for 4 variants of the Bed Bridge Test (BBT) in healthy adults, and to evaluate their measurement properties, including reliability and validity. Methodological cross-sectional study. University-based research setting. A total of 120 healthy adults (18-79y), equally distributed by sex, were included. Participants were independent in daily activities and free from significant clinical conditions. Participants performed 4 randomized variants of the BBT: 5 repetitions (5×BBT), 10 repetitions (10×BBT), 30 seconds (30s BBT), and 60 seconds (60s BBT), following standardized procedures. Normative values, reference equations, test-retest reliability (intraclass correlation coefficient), measurement error, floor and ceiling effects, and criterion and construct validity. Normative values were established according to age and sex. Performance declined with age and was higher in men across all variants. Reference equations explained 29%-46% of performance variability, with age and sex as significant predictors. The equations were: 5×BBT=3.49-1.96×(sex)+0.07×age; 10×BBT=6.93-4.51×(sex)+0.14×age; 30s BBT=44.21+9.36×(sex)-0.36×age; and 60s BBT=80.28+20.38×(sex)-0.62×age. All BBT variants demonstrated good to excellent reliability (intraclass correlation coefficient=0.87-0.95), with acceptable floor and ceiling effects. Criterion validity was supported by moderate to strong correlations with sit-to-stand tests. The BBT variants demonstrated adequate reliability and validity for assessing functional capacity in healthy adults. The normative values and reference equations provide preliminary support for clinical interpretation and may assist in identifying functional limitations and guiding rehabilitation strategies, particularly in individuals with reduced mobility.