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Optimization of energy and time predicts dynamic speeds for human walking
Humans make a number of choices when they walk, such as how fast and for how long. The preferred steady walking speed seems chosen to minimize energy expenditure per distance traveled. But the speed of actual walking bouts is not only steady, but rather a time-varying trajectory, which can also be m...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
eLife Sciences Publications, Ltd
2023
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10030114/ https://www.ncbi.nlm.nih.gov/pubmed/36779697 http://dx.doi.org/10.7554/eLife.81939 |
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author | Carlisle, Rebecca Elizabeth Kuo, Arthur D |
author_facet | Carlisle, Rebecca Elizabeth Kuo, Arthur D |
author_sort | Carlisle, Rebecca Elizabeth |
collection | PubMed |
description | Humans make a number of choices when they walk, such as how fast and for how long. The preferred steady walking speed seems chosen to minimize energy expenditure per distance traveled. But the speed of actual walking bouts is not only steady, but rather a time-varying trajectory, which can also be modulated by task urgency or an individual’s movement vigor. Here we show that speed trajectories and durations of human walking bouts are explained better by an objective to minimize Energy and Time, meaning the total work or energy to reach destination, plus a cost proportional to bout duration. Applied to a computational model of walking dynamics, this objective predicts dynamic speed vs. time trajectories with inverted U shapes. Model and human experiment (N=10) show that shorter bouts are unsteady and dominated by the time and effort of accelerating, and longer ones are steadier and faster and dominated by steady-state time and effort. Individual-dependent vigor may be characterized by the energy one is willing to spend to save a unit of time, which explains why some may walk faster than others, but everyone may have similar-shaped trajectories due to similar walking dynamics. Tradeoffs between energy and time costs can predict transient, steady, and vigor-related aspects of walking. |
format | Online Article Text |
id | pubmed-10030114 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2023 |
publisher | eLife Sciences Publications, Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-100301142023-03-22 Optimization of energy and time predicts dynamic speeds for human walking Carlisle, Rebecca Elizabeth Kuo, Arthur D eLife Computational and Systems Biology Humans make a number of choices when they walk, such as how fast and for how long. The preferred steady walking speed seems chosen to minimize energy expenditure per distance traveled. But the speed of actual walking bouts is not only steady, but rather a time-varying trajectory, which can also be modulated by task urgency or an individual’s movement vigor. Here we show that speed trajectories and durations of human walking bouts are explained better by an objective to minimize Energy and Time, meaning the total work or energy to reach destination, plus a cost proportional to bout duration. Applied to a computational model of walking dynamics, this objective predicts dynamic speed vs. time trajectories with inverted U shapes. Model and human experiment (N=10) show that shorter bouts are unsteady and dominated by the time and effort of accelerating, and longer ones are steadier and faster and dominated by steady-state time and effort. Individual-dependent vigor may be characterized by the energy one is willing to spend to save a unit of time, which explains why some may walk faster than others, but everyone may have similar-shaped trajectories due to similar walking dynamics. Tradeoffs between energy and time costs can predict transient, steady, and vigor-related aspects of walking. eLife Sciences Publications, Ltd 2023-02-13 /pmc/articles/PMC10030114/ /pubmed/36779697 http://dx.doi.org/10.7554/eLife.81939 Text en © 2023, Carlisle and Kuo https://creativecommons.org/licenses/by/4.0/This article is distributed under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0/) , which permits unrestricted use and redistribution provided that the original author and source are credited. |
spellingShingle | Computational and Systems Biology Carlisle, Rebecca Elizabeth Kuo, Arthur D Optimization of energy and time predicts dynamic speeds for human walking |
title | Optimization of energy and time predicts dynamic speeds for human walking |
title_full | Optimization of energy and time predicts dynamic speeds for human walking |
title_fullStr | Optimization of energy and time predicts dynamic speeds for human walking |
title_full_unstemmed | Optimization of energy and time predicts dynamic speeds for human walking |
title_short | Optimization of energy and time predicts dynamic speeds for human walking |
title_sort | optimization of energy and time predicts dynamic speeds for human walking |
topic | Computational and Systems Biology |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10030114/ https://www.ncbi.nlm.nih.gov/pubmed/36779697 http://dx.doi.org/10.7554/eLife.81939 |
work_keys_str_mv | AT carlislerebeccaelizabeth optimizationofenergyandtimepredictsdynamicspeedsforhumanwalking AT kuoarthurd optimizationofenergyandtimepredictsdynamicspeedsforhumanwalking |