The Biomechanics of Arboreal Stability: An Integrated Analysis

长期以来，生物人类学家一直对灵长类动物成功入侵树栖栖息地的适应保持着浓厚的兴趣，在树栖栖息地，稳定性是至高无上的。几十年的研究已经确定了一些解剖特征，比如抓握手和脚，以及行为机制，比如使用独特的行走方式，这可以说有助于树枝上的稳定。然而，对于灵长类动物在树上活动时保持平衡的机制，我们仍然有一个不完全的理解。这项拟议的研究将通过开展一系列实验来了解新大陆和东半球猴子的平衡能力，从而弥补这一差距。通过这样做，我们将对灵长类动物和人类进化的几个基本问题有更深入的了解--例如抓住手和脚的功能重要性，以及猿类失去尾巴的可能后果。有关普通实验室灵长类动物平衡能力的基本数据，也可能对在更多临床环境中研究灵长类稳定性的研究人员有用，或许有助于揭示人类平衡障碍。此外，这项研究产生的合作将扩大STEM学生在主办机构和邻近学院和大学的教育经验，有助于在整个地区建立一个研究和培训的合作网络。首先，为了确定形态变化与握力产生能力之间的关系，功能知情的手足肌肉骨骼解剖将与最大握力的实验数据相结合。其次，为了生成稳定性的量化指标，研究人员将收集猴子在模拟树栖基质上移动的详细生物力学数据。最后，安装在压缩弹簧上的一系列力传感器将用于测量移动分支的平衡性能，在更自然的环境中提供一种树上平衡控制的措施。这一基础生物力学研究将1)检验长期以来关于灵长类运动适应性质的假设，2)重建灵长类化石记录中的抓取能力和运动能力，3)将一套新的研究方法引入生物人类学学科。

Biological anthropologists have long maintained a keen interest in the adaptations that allowed primates to successfully invade the arboreal habitat, where stability is paramount. Decades of research have identified anatomical features, such as grasping hands and feet, and behavioral mechanisms, such as the use of distinctive walking styles, which arguably facilitate stability on branches. Nevertheless, we still have an incomplete understanding of the mechanisms by which primates actually keep balance when moving about in the trees. The proposed research will remedy this gap by carrying out a series of experiments to understand balance performance in both New and Old World monkeys. In so doing, we will gain deeper insight into several fundamental issues of primate, and human, evolution -- such as the functional importance of grasping hands and feet and the possible consequences of tail loss among the apes. Basic data on the balance capabilities of common laboratory primates may also be of use to researchers studying primate stability in more clinical settings, perhaps shedding light on human balance disorders. Moreover, the collaborations engendered by this research will broaden educational experiences of STEM students at the host institution and neighboring colleges and universities, helping to build a collaborative network of research and training throughout the region.Investigators will address three specific research aims. First, to determine the relationship between morphological variation and the capacity for grasping force production, functionally-informed hand and foot musculoskeletal anatomy will be combined with experimental data on maximum grip strength. Second, to generate quantitative measures of stability, researchers will collect detailed biomechanical data from monkeys moving over simulated arboreal substrates. Finally, a series of force sensors mounted on compression springs will be used to gauge balance performance on mobile branches, providing a measure of arboreal balance control in a more naturalistic setting. This fundamental biomechanical research will 1) allow testing of long-held assumptions about the nature of primate locomotor adaptation, 2) inform reconstructions of grasping ability and locomotor performance in the primate fossil record, and 3) introduce a novel set of research methodologies to the discipline of biological anthropology.