Abstract
Older adults typically consume 10 to 25% more metabolic energy than young adults while walking (decreased walking economy). The age-related decline in walking economy relates to impaired quality of life and is important to mitigate (or reverse). Yet, it is unestablished which factor(s) govern the age-related decline in the walking economy. Based on recent findings that older adult neural control strategies during walking likely increase their metabolic rate, we sought to test whether age-related metabolic differences persist during simple joint-level tasks. PURPOSE: The purpose of this study is to infer whether the musculoskeletal system directly affects the age-related decline in walking economy. METHODS: Three older adults (avg. ± SD:78.3 ± 1.2 years) and 10 young adults (23.7 ± 0.8 years) participated. Session 1: After familiarization, participants walked on a treadmill at 0.8 m/s and 1.3 m/s for 5-min with seated rest preceding each trial. Session 2: Participants sat on a chair with their right leg secured in a fixed position that emulates joint angles during walking. Participants performed 5-min trials where they cyclically produced fixed-end ankle extension moments following visual and audio feedback (20 and 30 Nm peak moment, 0.75 Hz, 0.5 duty). Next, participants performed the same 5-min trials using their hip extensors while lying with their hip joint at 160°. We randomized the order of ankle and hip trials. We quantified net V̇o2 uptake and V̇co2 production via open-circuit spirometry during all trials and used a standard equation to compute net metabolic power. RESULTS: Consistent with the literature, older adults required 32-36% more net metabolic power to walk than young adults. While cyclically producing joint moments on a dynamometer, older adults consumed 12 to 40 more metabolic power (W) at the ankle and hip than young adults. These greater joint-level metabolic values occurred despite older adults producing 5-14% lower cycle average moments compared to young adults across ankle trials, and 27-48% lower cycle average moments across hip trials. So, despite older adults producing decreased joint moments, they still consumed more metabolic energy to operate their joints than young adults. CONCLUSION: Based on our preliminary findings, it is likely that the aging musculoskeletal system measurably contributes to the age-related decline in the walking economy. Therefore, interventions that maintain youthful musculoskeletal health are warranted to mitigate the age-related decline in walking economy.
Recommended Citation
'Measeles' Alanis, Brooke; Fallah, Negin; Mistry, Ahan; and Beck, Owen N.
(2025)
"Neural or Musculoskeletal: Which System Drives the Age-Related Decline in Walking Economy?,"
International Journal of Exercise Science: Conference Proceedings: Vol. 2:
Iss.
17, Article 100.
Available at:
https://digitalcommons.wku.edu/ijesab/vol2/iss17/100