Collaborative Research: The Effects of Musculoskeletal Design on Bipedal Walking and Running Performance

在人类的背部、骨盆和下肢的大小和形状上，人类在类人猿和其他灵长类动物中是独一无二的，所有这些都有助于我们用两条腿走路和跑步。这个项目的主要目标是阐明人类最早的祖先的行走和奔跑能力，人类化石记录表明，他们只拥有这些解剖特征的一个子集。为了实现这一目标，该项目将把人类和黑猩猩的运动实验与计算机模拟结合起来，使用人类、黑猩猩和大约350万年前的人类祖先南方古猿的肌肉和骨骼解剖的详细模型进行模拟。这种综合的实验建模/模拟方法将建立解剖特征与行走和跑步能力之间的关系。该项目将把生物人类学和计算科学研究联系起来，包括开发新的工具，为根据人类祖先的化石推断行走和跑步能力提供严格的量化基础。它还将促进本科生、研究生和博士后水平的教育和培训，并包括对促进学术多样性和包容性的坚定承诺。所产生的知识将被纳入一年一度的高中生生物力学推广活动，以及为生物人类学研究人员提供计算机建模和模拟技能的讲习班。与这个项目相关的数据、模型和算法将在网上与其他科学家、教育工作者和公众共享。在过去的700到800万年里，我们的肌肉、骨骼和神经系统已经适应了地面运动。我们的血统是如何变成熟练的步行者和跑步者的，以及最早的古人类之间发生了什么样的运动适应？这个问题将通过将经验运动数据与肌肉骨骼系统的详细模型和预测模拟的最新进展相结合来解决。首先，将为两足黑猩猩和人类在匹配速度下的3-D肢体运动、力量和成本建立一个全面的实验数据集。该数据集将用于验证两个分类群中基于模型的步行和跑步的预测性模拟，并评估三个与生态相关的性能标准，包括能源成本、肌肉疲劳和关节负荷，以及所有这三个指标的加权组合。Au的三维模型。然后，将使用阿法尔种与最佳表现标准一起预测该物种的行走和跑步能力，并通过敏感度分析评估不确定性。综上所述，这些数据将为开发早期类人类人猿可变形的肌肉骨骼模型提供基础，以检验以下背部和骨盆进化增强两足行走和奔跑能力的假说。最后，将开发一种新的两级预测模拟方法，以发现驱动两足动物运动中解剖特征进化的选择性力量。这种综合的方法将提供有关早期人类行走和奔跑能力的关键信息，这些能力是仅通过基于化石的比较研究或实验无法接近的。该项目由生物人类学、生理机制和生物力学项目共同支持。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Humans are unique among apes and other primates in the size and shape of our back, pelvis and lower limbs, all of which contribute to the ease with which we walk and run on two limbs. The main goal of this project is to elucidate the walking and running capabilities of the earliest human ancestors, who – the human fossil record indicates – possessed only a subset of these anatomical traits. To achieve this goal, this project will integrate locomotor experiments of humans and chimpanzees with computer simulations using detailed models of the muscle and skeletal anatomies of humans, chimpanzees and Australopithecus afarensis, a ~3.5 million year old human ancestor. This integrative experiment-modeling/simulation approach will establish relationships between anatomical traits and walking and running capabilities. The project will link biological anthropology and computational science research, including the development of new tools that provide a rigorous, quantitative basis for inferring walking and running capabilities from fossils of human ancestors. It will also contribute to education and training at the undergraduate, graduate, and postdoctoral levels, and include a strong commitment to advancing academic diversity and inclusion. The knowledge generated will be incorporated into an annual biomechanics outreach event for high school students and a workshop providing computer modeling and simulation skills for researchers in biological anthropology. Data, models, and algorithms associated with this project will be shared online with other scientists, educators, and the general public.Over the past 7 to 8 million years, our muscular, skeletal, and neural systems have been adapted for overground locomotion. How did our lineage become skilled walkers and runners, and what locomotor adaptations occurred among the earliest hominins? This question will be addressed by integrating empirical locomotion data with detailed models of the musculoskeletal system and the latest advances in predictive simulation. First, a comprehensive experimental dataset will be established for the 3-D limb motion, forces, and cost for bipedal chimpanzee and human locomotion at matched speeds. This dataset will be used to validate model-based, predictive simulations of walking and running in both taxa, and evaluate three ecologically-relevant performance criteria, including energy cost, muscle fatigue, and joint loading, as well as a weighted combination of all three. A 3-D model of Au. afarensis will then be used with the best-performing criteria to predict walking and running capabilities for this species, with uncertainty assessed via sensitivity analyses. Together, these data will provide the basis for developing an early hominin-like deformable ape musculoskeletal model to test the hypothesis that lower back and pelvis evolution enhanced bipedal walking and running capabilities as compared to bipedal locomotion in chimpanzees. Finally, a new bi-level predictive simulation approach will be developed for discovering the selective forces that drive anatomical trait evolution in bipedal locomotion. This integrative approach will provide critical information about walking and running capabilities in the earliest hominins that have been unapproachable using comparative fossil-based studies or experimentation alone. This project is jointly supported by the Biological Anthropology and Physiological Mechanisms and Biomechanics Programs.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.