Wang Weijie, Abboud Rami J, Günther Michael M, Crompton Robin H
Department of Orthopaedic and Trauma Surgery, Institute of Motion Analysis and Research, The Ninewells Hospital and Medical School, The University of Dundee, Dundee, UK; The School of Mathematics and Physics, Nanjing University of Information Science and Technology, Nanjing, China.
J Anat. 2014 Aug;225(2):152-66. doi: 10.1111/joa.12201. Epub 2014 Jun 13.
The feet of apes have a different morphology from those of humans. Until now, it has merely been assumed that the morphology seen in humans must be adaptive for habitual bipedal walking, as the habitual use of bipedal walking is generally regarded as one of the most clear-cut differences between humans and apes. This study asks simply whether human skeletal proportions do actually enhance foot performance during human-like bipedalism, by examining the influence of foot proportions on force, torque and work in the foot joints during simulated bipedal walking. Skeletons of the common chimpanzee, orangutan, gorilla and human were represented by multi-rigid-body models, where the components of the foot make external contact via finite element surfaces. The models were driven by identical joint motion functions collected from experiments on human walking. Simulated contact forces between the ground and the foot were found to be reasonably comparable with measurements made during human walking using pressure- and force-platforms. Joint force, torque and work in the foot were then predicted. Within the limitations of our model, the results show that during simulated human-like bipedal walking, (1) the human and non-human ape (NHA) feet carry similar joint forces, although the distributions of the forces differ; (2) the NHA foot incurs larger joint torques than does the human foot, although the human foot has higher values in the first tarso-metatarsal and metatarso-phalangeal joints, whereas the NHA foot incurs higher values in the lateral digits; and (3) total work in the metatarso-phalangeal joints is lower in the human foot than in the NHA foot. The results indicate that human foot proportions are indeed well suited to performance in normal human walking.
猿类的足部形态与人类不同。到目前为止，人们仅仅假定人类所呈现出的形态必定适应习惯性两足行走，因为习惯性两足行走通常被视为人类与猿类之间最明显的差异之一。本研究只是通过考察足部比例对模拟两足行走过程中足部关节的力、扭矩和功的影响，来探究人类骨骼比例在类人两足行走过程中是否真的能提升足部性能。普通黑猩猩、猩猩、大猩猩和人类的骨骼由多刚体模型表示，其中足部各组成部分通过有限元表面与外界接触。这些模型由从人类行走实验中收集的相同关节运动函数驱动。发现地面与足部之间的模拟接触力与使用压力平台和力平台在人类行走过程中所做的测量结果具有合理的可比性。然后预测了足部的关节力、扭矩和功。在我们模型的局限性范围内，结果表明，在模拟类人两足行走过程中，(1)人类和非人类猿类（NHA）的足部承受相似的关节力，尽管力的分布不同；(2)NHA足部产生的关节扭矩比人类足部大，尽管人类足部在第一跗跖关节和跖趾关节处的值较高，而NHA足部在外侧趾处的值较高；(3)人类足部跖趾关节的总功低于NHA足部。结果表明，人类足部比例确实非常适合正常人类行走的性能。
