Impact of balance on the energetic cost of walking and gait speed.

backgroundExamine the relationship between balance test performance and the energetic cost of walking (ECW) and gait speed.

methodsCross-sectional and longitudinal analyses of data from the Baltimore Longitudinal Study of Aging. Men (48%) and women aged 60-96 years enrolled in the BLSA between 2007 and 2020 (n = 1132). Balance was assessed using narrow walk (NW) and progressive standing balance tests (SB). ECW measured during 2.5-min usual paced walk while participants wore a portable indirect calorimeter. Gait speed assessed over 6-m. Each test parameterized using validated methods. Statistical analysis to compare balance measures to ECW, and gait speed used generalized logistic regression models and adjustments for age, sex, race, height, weight, and comorbidities.

resultsCross-sectionally, mean ECW was higher and gait speed slower in persons who failed the NW than those who passed (0.189 vs. 0.164 mL/kg/m, p < 0.0001 and 0.96 vs. 1.15 m/s, p < 0.0001, respectively). Mean ECW was increasingly higher and gait speed slower over three progressively challenging SB tests (0.207 vs. 0.171 vs. 0.164 mL/kg/m, p < 0.0001 and 0.95 vs. 1.05 vs. 1.15 m/s, p < 0.0001). Over an average 2.4 years, those who declined in SB and NW had a higher ECW and slower gait speed than persons who maintained performance (SB: 0.18 vs. 0.160 mL/kg/m, p = 0.0003, and 1.00 vs. 1.13 m/s, p = <0.001; NW: 0.175 vs. 0.160 mL/kg/m, p = 0.002, and 1.04 vs. 1.14 m/s, p = 0.001). Persons who improved had lower ECW and faster gait speed than those who failed at both visits (SB: 0.169 vs. 0.240 mL/kg/m, p = 0.0002, and 0.99 vs. 0.94 m/s, p = 0.67, NW: 0.163 vs. 0.195 mL/kg/m, p = 0.0005, and 1.10 vs. 0.92 m/s, p < 0.001).

conclusionInstability contributes to higher ECW and slower gait speed which suggests that rehabilitation efforts to improve balance may help maintain function further into older adulthood and delay mobility limitation.