Metabolic cost and co-contraction during walking at different speeds in young and old adults.

TitreMetabolic cost and co-contraction during walking at different speeds in young and old adults.
Publication TypeJournal Article
Year of Publication2022
AuthorsPiche E, Chorin F, Zory R, Freitas PDuarte, GuÉrin O, Gerus P
JournalGait Posture
Date Published2022 01
Mots-clésAdult, Aged, Biomechanical Phenomena, Electromyography, Gait, Humans, Knee, Knee Joint, Middle Aged, Muscle, Skeletal, Walking, Young Adult

BACKGROUND: The net metabolic cost of walking (NCw) and the co-activation of leg muscles are both higher in old adults (OG) than in young adults (YG). Nevertheless, the relation between the two remains unresolved, mainly due to the controversial co-activation measurement method used in previous studies.RESEARCH QUESTION: To compare ankle and knee co-contraction (CCI), calculated using an EMG-driven method, between the groups and to examine their relationship with NCw.METHODS: Nine young (YG = 25.2 +/- 3.3 years old) and nine older (OG = 68.7 +/5.9 years old) adults walked on a treadmill at five speeds (YG: 1; 1.2; 1.4; 1.6; 1.8 m/s; OG: 0.6; 0.8; 1; 1.2; 1.4 m/s) while electromyography (sEMG) and oxygen consumption were measured. CCI were calculated around the ankle and knee for different parts of the gait cycle (entire gait cycle 0-100 %, stance phase 0-60 %, swing phase 60-100 %).RESULTS: NCw was significantly higher (25 %, averaged over the walking speeds) in OG as were Knee_CCI, Knee_CCI_swing and Knee_CCI_stance. Multiple regression models in YG, OG and YG + OG highlighted Ankle_CCI as the main contributor in NCw (β = 0.08-0.188, p < 0.05) with a positive relation between the two variables.SIGNIFICANCE: The present findings provide a better understanding of the association between muscle co-contraction and metabolic cost in older adults. It may help scientists and clinicians to further develop strategies aimed at neuromuscular rehabilitation as a means of improving mobility and independence among older adults.

Alternate JournalGait Posture
PubMed ID34673446