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Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support
Whether tree canopy habitats played a sustained role in the ecology of ancestral bipedal hominins is unresolved. Some argue that arboreal bipedalism was prohibitively risky for hominins whose increasingly modern anatomy prevented them from gripping branches with their feet. Balancing on two legs is...
Autores principales: | , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group UK
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5430707/ https://www.ncbi.nlm.nih.gov/pubmed/28442732 http://dx.doi.org/10.1038/s41598-017-01265-7 |
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author | Johannsen, L. Coward, S. R. L. Martin, G. R. Wing, A. M. Casteren, A. van Sellers, W. I. Ennos, A. R. Crompton, R. H. Thorpe, S. K. S. |
author_facet | Johannsen, L. Coward, S. R. L. Martin, G. R. Wing, A. M. Casteren, A. van Sellers, W. I. Ennos, A. R. Crompton, R. H. Thorpe, S. K. S. |
author_sort | Johannsen, L. |
collection | PubMed |
description | Whether tree canopy habitats played a sustained role in the ecology of ancestral bipedal hominins is unresolved. Some argue that arboreal bipedalism was prohibitively risky for hominins whose increasingly modern anatomy prevented them from gripping branches with their feet. Balancing on two legs is indeed challenging for humans under optimal conditions let alone in forest canopy, which is physically and visually highly dynamic. Here we quantify the impact of forest canopy characteristics on postural stability in humans. Viewing a movie of swaying branches while standing on a branch-like bouncy springboard destabilised the participants as much as wearing a blindfold. However “light touch”, a sensorimotor strategy based on light fingertip support, significantly enhanced their balance and lowered their thigh muscle activity by up to 30%. This demonstrates how a light touch strategy could have been central to our ancestor’s ability to avoid falls and reduce the mechanical and metabolic cost of arboreal feeding and movement. Our results may also indicate that some adaptations in the hand that facilitated continued access to forest canopy may have complemented, rather than opposed, adaptations that facilitated precise manipulation and tool use. |
format | Online Article Text |
id | pubmed-5430707 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Nature Publishing Group UK |
record_format | MEDLINE/PubMed |
spelling | pubmed-54307072017-05-16 Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support Johannsen, L. Coward, S. R. L. Martin, G. R. Wing, A. M. Casteren, A. van Sellers, W. I. Ennos, A. R. Crompton, R. H. Thorpe, S. K. S. Sci Rep Article Whether tree canopy habitats played a sustained role in the ecology of ancestral bipedal hominins is unresolved. Some argue that arboreal bipedalism was prohibitively risky for hominins whose increasingly modern anatomy prevented them from gripping branches with their feet. Balancing on two legs is indeed challenging for humans under optimal conditions let alone in forest canopy, which is physically and visually highly dynamic. Here we quantify the impact of forest canopy characteristics on postural stability in humans. Viewing a movie of swaying branches while standing on a branch-like bouncy springboard destabilised the participants as much as wearing a blindfold. However “light touch”, a sensorimotor strategy based on light fingertip support, significantly enhanced their balance and lowered their thigh muscle activity by up to 30%. This demonstrates how a light touch strategy could have been central to our ancestor’s ability to avoid falls and reduce the mechanical and metabolic cost of arboreal feeding and movement. Our results may also indicate that some adaptations in the hand that facilitated continued access to forest canopy may have complemented, rather than opposed, adaptations that facilitated precise manipulation and tool use. Nature Publishing Group UK 2017-04-25 /pmc/articles/PMC5430707/ /pubmed/28442732 http://dx.doi.org/10.1038/s41598-017-01265-7 Text en © The Author(s) 2017 Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/. |
spellingShingle | Article Johannsen, L. Coward, S. R. L. Martin, G. R. Wing, A. M. Casteren, A. van Sellers, W. I. Ennos, A. R. Crompton, R. H. Thorpe, S. K. S. Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title | Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title_full | Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title_fullStr | Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title_full_unstemmed | Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title_short | Human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
title_sort | human bipedal instability in tree canopy environments is reduced by “light touch” fingertip support |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5430707/ https://www.ncbi.nlm.nih.gov/pubmed/28442732 http://dx.doi.org/10.1038/s41598-017-01265-7 |
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