Demes B, Jungers W L
Ruhr-Universität Bochum, FRG.
Folia Primatol (Basel). 1989;52(1-2):58-69. doi: 10.1159/000156381.
The external dimensions of the limb bones and the geometry of their midshaft cross-sections were determined for Loris tardigradus and Nycticebus coucang. Relative cortical thickness, cortical area, and second moment of area were calculated and contrasted with locomotor stresses. The difference in shape-related strength of the bones between the smaller- and the larger-bodied species is more pronounced than can be expected from stresses acting during normal locomotion. The Nycticebus skeleton has a much higher safety margin overall and seems to be dimensioned for infrequent but critical stresses of high magnitude. Lorisine gaits in general are characterized by low ground reaction forces, great mobility in all joints, and a nearly equal share in propulsion and weight-bearing by the fore- and hindlimb. Accordingly, the long bones of lorises (especially those of L. tardigradus) tend to be less rigid than those of other mammalian species (including other primates), they lack a preferential plane of higher bending strength, and femur and humerus do not differ markedly in their capacity to withstand mechanical stresses. External dimensions of the humerus and femur of the two African lorisine species parallel and corroborate these results. Some more general implications for the relationships between bone shape and locomotor stresses are also discussed.
测定了懒猴和蜂猴四肢骨骼的外部尺寸及其骨干中段横截面的几何形状。计算了相对皮质厚度、皮质面积和面积惯性矩，并与运动应力进行了对比。体型较小和体型较大的物种之间，骨骼在形状相关强度上的差异比正常运动时所受应力预期的更为明显。蜂猴的骨骼总体上具有更高的安全系数，其尺寸似乎是为应对不频繁但强度较大的关键应力而设计的。一般来说，懒猴的步态特点是地面反作用力较低，所有关节的活动度较大，前肢和后肢在推进和承重方面的分担几乎相等。因此，懒猴的长骨（尤其是懒猴的长骨）往往比其他哺乳动物（包括其他灵长类动物）的长骨刚性更差，它们缺乏抗弯强度更高的优先平面，股骨和肱骨在承受机械应力的能力上没有明显差异。两种非洲懒猴科物种的肱骨和股骨的外部尺寸与这些结果相符并得到了证实。还讨论了骨骼形状与运动应力之间关系的一些更普遍的影响。
