Citation

Wu M, Brown GL, Woodward JL, Bruijn SM, Gordon KE. R. Soc. Open Sci. 2020; 7(1): e190889.

Affiliation

Research Service, Edward Hines Jr. Veterans Administration Hospital, Hines, IL, USA.

Copyright

(Copyright © 2020, Royal Society Publishing)

DOI

10.1098/rsos.190889

PMID

32218932

PMCID

PMC7029926

Abstract

During human walking, the centre of mass (COM) laterally oscillates, regularly transitioning its position above the two alternating support limbs. To maintain upright forward-directed walking, lateral COM excursion should remain within the base of support, on average. As necessary, humans can modify COM motion through various methods, including foot placement. How the nervous system controls these oscillations and the costs associated with control are not fully understood. To examine how lateral COM motions are controlled, healthy participants walked in a 'Movement Amplification' force field that increased lateral COM momentum in a manner dependent on the participant's own motion (forces were applied to the pelvis proportional to and in the same direction as lateral COM velocity). We hypothesized that metabolic cost to control lateral COM motion would increase with the gain of the field. In the Movement Amplification field, participants were significantly less stable than during baseline walking. Stability significantly decreased as the field gain increased. Participants also modified gait patterns, including increasing step width, which increased the metabolic cost of transport as the field gain increased. These results support previous research suggesting that humans modulate foot placement to control lateral COM motion, incurring a metabolic cost.

© 2020 The Authors.

Language: en

Keywords

Movement Amplification; centre of mass control; locomotion; metabolic cost; stability