二足直立行走的生物力学特征和南方古猿阿法种可能的行走方式

BIOMECHANICAL CHARACTERISTICS OF BIPEDALISM AND POSSIBLE LOCOMOTION MODE OF AUSTRALOPITHECUS

生活于300万年前的南方古猿的行走方式一直是古人类学家关注争论的焦点之一。尽管标本露西(AL288)保留有大部长骨和盆骨,使得研究者有可能对其全身形态结构进行复原。从形态结构出发,不同的研究者对于这一标本所代表的个体在直立行走方面的能力,仍有很大的歧见。本文以露西的人体测量数据为基础,辅以现代人及黑猩猩的身体质量分布数据,建立起一套露西的静力学模型,并应用计算机模拟技术,以各种可能行走方式的运动方程"驱动"静力学模型,由此分析各种静力模型/运动方程组合导致的生物力学特征。最初结果显示,若露西以现代人运动方程直立行走,髋、膝、踝关节的能量消耗较小,且分布比较合理。但深一层的分析显示,包括露西在内的南方古猿股骨标本均表现了较强的在矢状面的抗变形能力与以屈膝屈髋方式行走的露西的力学需求相合,显示另外一种可能性的存在。

The locomotion mode of Australopithecus has long been a hot topic for palaeoanthropologists. The fossil specimen of Lucy(A1288-1) has its most long bones and pelvis preserved, so that researchers may have a detailed study on her body morphology and skeleton structure. Even based on the exact the same morphological data, there is still, oddly, a major and prolonged disagreement.Starting from Lucy's anthropometric data and aided by the computer simulation technique, this study built a series of dynamic modes, with a combination of lower limb joint moving functions and static characteristics of Lucy. It was shown that had Lucy had walked with a bent-knee, bent-hip(BKBH) posture, it would have been much more expensive in energy consumption than otherwise if she were walking in a fully erect manner. This suggested that Lucy may have been walking bipedally and erectly just like us today. However, further analysis indicates that the femurs of Australopithecus including Lucy's are of stronger anti-deformation ability in both sagittal and frontal plans, agreeing the joint torque output for the BKBH model built in this study. This finding suggests a total different conclusion.