Human bipedal instability in tree canopy environments is reduced by "light touch" fingertip support.
Human bipedal instability in tree canopy environments is reduced by "light touch" fingertip support.
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DOI：
10.1038/s41598-017-01265-7
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发表时间：
2017-04-25
影响因子：
4.6
通讯作者：
Thorpe SKS
中科院分区：
文献类型：
--
作者：
Johannsen L;Coward SRL;Martin GR;Wing AM;Casteren AV;Sellers WI;Ennos AR;Crompton RH;Thorpe SKS
树冠栖息地是否在两足古人类祖先的生态学中发挥了持续的作用还没有得到解决。一些人认为，树栖两足行走对人类来说是一种极其危险的行为，因为人类越来越现代的解剖结构使他们无法用脚抓住树枝。在最佳条件下，用两条腿保持平衡对人类来说确实是一项挑战，更不用说在身体和视觉高度动态的森林树冠中了。在这里，我们量化的森林冠层特征对人体姿势稳定性的影响。站在树枝状的弹性跳板上观看树枝摇摆的电影，参与者的不稳定程度与戴上眼罩一样。然而，“轻触”，一种基于指尖轻微支撑的感觉运动策略，显着增强了他们的平衡能力，并将大腿肌肉活动降低了30%。这表明，轻触策略可能是我们祖先避免福尔斯和减少机械和代谢成本的能力的核心。我们的研究结果也可能表明，一些适应性的手，促进继续进入森林冠层可能补充，而不是反对，适应性，促进精确的操作和工具的使用。
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.