A balance-weighted gait score (BWGS) reflects biomechanical and control features of gait in older adults

BACKGROUND: Gait performance in older adults reflects the integrated function of balance, lower-extremity strength, and symptom-related factors such as musculoskeletal pain. However, commonly used clinical measures provide limited insight into the functional organization of gait control. OBJECTIVE: To develop and evaluate the Balance-Weighted Gait Score (BWGS), a composite index derived from simple clinical measures, and to examine its construct validity and associations with gait characteristics in older adults. METHODS: Participants aged 60-96 years from the Baltimore Longitudinal Study of Aging (BLSA) who completed balance assessments were included (n = 428). BWGS was derived using ordinary least squares regression, integrating chair-rise time, narrow-based walking performance, and knee pain. Construct validity was evaluated using one-leg stance time as an independent measure of balance performance. Associations between BWGS and spatiotemporal, kinematic, and kinetic gait parameters were analyzed. Fall history was included for descriptive comparison. RESULTS: Higher BWGS values were associated with faster gait speed, longer stride length, greater joint range of motion at the hip, knee, and ankle, increased mechanical work expenditure, and narrower stride width (all p < 0.05). Higher BWGS was also associated with one-leg stance performance, providing supportive evidence of construct validity. These associations showed distinct patterns when stratified by fall history. CONCLUSION: BWGS provides a simple and clinically interpretable index reflecting key biomechanical and control-related features of gait. By integrating multiple functional components into a single metric and demonstrating construct validity against independent balance performance, BWGS offers a practical tool for characterizing balance-related gait regulation in older adults.