Doctoral Dissertation Improvement: Biomechanical and Behavioral Significance of the Neanderthal Femur

许多研究人员认为，与现代人类相比，尼安德特人股骨的健壮性和合成强度更大，这是由于在觅食和狩猎时的长期使用。 这就是所谓的流动性假说。 这项研究通过检查大样本灵长类动物的骨骼特征和测距行为来验证这一假设，以确定使用是否等同于更大的健壮性。 研究结果将为人类学、灵长类动物学、整形外科学、工程学和数量遗传学等领域提供信息。 这项研究还影响了对股骨力学环境的理解，这可能有助于髋关节假体的发展。 此外，这项研究提高了对遗传学和股骨形态学之间相关性的理解，促进了工程学和社会科学之间的跨学科研究。尼安德特人的股骨在四个方面与现代人的股骨不同，这表明它更坚固，或生物力学更强：它更弯曲，骨骼更厚，轴是圆形而不是椭圆形，颈干角更小。 这些差异可以用流动性假说来解释。 由于生存策略严重依赖于动物资源的开发，尼安德特人可能比现代人更远地旅行寻找食物，因此在更大程度上加载了他们的下肢。 本研究采用三阶段方法检验流动性假设。 第一阶段建立了一个比较基础，在35种活的灵长类动物与记录的测距行为的股骨骨骼特征的流动性，使用的方法，将产生和传播数百个计算机化的3D表面模型。 第二阶段使用21个品系的近交系实验室小鼠共413个个体分析关键骨骼特征的遗传或环境产生的程度。 最后一个阶段探索完整的尼安德特人和现代人类股骨在每个物种的特定解剖背景下的力量，使用工程技术（有限元分析），旨在研究复杂结构如何响应负载，并包括现实肌肉和髋关节反作用力的影响。

Many researchers have suggested that the greater robusticity and resultant strength of Neandertal femora, compared with those of modern humans, is due to extended use while foraging and hunting. This is known as the mobility hypothesis. This study examines that hypothesis by examining skeletal features and ranging behaviors in a large sample of living primates to determine if use equates with greater robusticity. Results will inform the fields of anthropology, primatology, orthopedics, engineering, and quantitative genetics. The study also impacts understanding of the femur's mechanical environment, which could aid the development of hip prosthetics. Furthermore, this study improves understanding of the correlation between genetics and femoral morphology, and promotes interdisciplinarity between engineering and social sciences.The Neanderthal femur differs from that of recent modern humans in four ways that suggest it is more robust, or biomechanically stronger: it is more curved, has thicker bone, a round rather than elliptical shaft, and a smaller neck-shaft angle. These differences may be explained by the mobility hypothesis. Due to subsistence strategies relying heavily on the exploitation of animal resources, Neanderthals may have been traveling farther than modern humans in search of food, and would thus be loading their lower limbs to a greater extent. This study tests the mobility hypothesis using a three phase approach. The first phase establishes a comparative basis relating mobility to femoral skeletal features in 35 species of living primates with documented ranging behavior, using a method that will produce and disseminate hundreds of computerized 3D surface models. The second phase analyzes the degree to which key skeletal features are heritable or environmentally produced using 21 strains of inbred laboratory mice totaling 413 individuals. The final phase explores the strength of complete Neanderthal and modern human femora within each species' particular anatomical context, using an engineering technique (finite element analysis) designed to investigate how complex structures respond to loads, and include the impact of realistic muscle and hip joint reaction forces.