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Using 15 parameters, we provide a systematic description of mammal proximal femoral morphology. We established two types of proximal femoral morphology, termed coxa recta and coxa rotunda, characterized by low versus high concavity of the head-neck junction. Concavity is a measure of the sphericity of the femoral head as it meets the femoral neck that can be quantified by angular measurements. We asked whether the parameter of concavity corresponds with the classification of mammal proximal femoral morphology based on coalesced versus separate ossification patterns and locomotor patterns. Statistical analysis demonstrated a distinction between coxa recta and coxa rotunda with significant differences between the two groups in all but 3 of the 15 parameters examined. We found the most discriminating measurement between mammal hips to be the concavity of the posterior head-neck junction (beta angle). Coxa recta (small concavity) and coxa rotunda (large concavity) relate to the ossification pattern seen in proximal femoral development, and species-specific patterns of locomotion. We interpret the two hip types to reflect optimization for strength (recta) versus mobility (rotunda). Conceptually, both hip types can be recognized in humans, where coxa recta can be related to the development of osteoarthritis., (Copyright © 2012 Wiley Periodicals, Inc.)

The morphology of the talus prescribes relative positions and movements of the calcaneus and navicular with respect to the tibia, hence determining the overall geometry, mobility and function of the foot that mechanically interacts with environments. Clarifying the variations of the articular surface orientations of the talus in humans and extant great apes is therefore of importance in understanding the evolution of bipedal locomotion in the human lineage. The aim of this study is to clarify the three-dimensional orientations of three articular surfaces of the talus (superior, posterior calcaneal and navicular articular surfaces) by means of the newly proposed surface approximation method. Thirty-two tali in humans, chimpanzees, gorillas and orangutans were scanned using a three-dimensional noncontact digitizer, and the articular surfaces were then approximated using a paraboloid or a plane to calculate the orientations of the surfaces with respect to the body of the talus. The results quantitatively demonstrated that the superior articular surfaces in humans were relatively more parallel with the horizontal plane of the talar body, while those in apes were more medially oriented. Furthermore, the cylindrical axis defined by the shape of the posterior calcaneal articular surface was directed less anteroposteriorly in humans than in apes, in contrast to the fact that the subtalar axis is more anteroposteriorly oriented in humans. It was also demonstrated that the navicular articular surface in humans was more plantarly oriented and axially twisted. These specialized features of the human talus seem to be functionally linked to obligate bipedal locomotion. The talar morphological differences among the great apes were prominent in the mediolateral and rotational orientations of the navicular articular surfaces, possibly reflecting the degree of arboreality among the great apes.

Here I analyze the anatomical thought of the French physician and naturalist Félix Vicq d'Azyr (1748-1794) in order to bring to light its importance in the development of comparative anatomy at the end of the eighteenth century. I argue that his work and career can be understood as an ambitious program for a radical reform of all biomedical sciences and a reorganization of this whole field around comparative anatomy, on the conceptual as well as the institutional level. In particular, he recommended a close connection between anatomical and physiological studies, and a generalization of the comparative approach towards organs and functions in man and animals. This conception led him not only to reform the scope, the methods, the style of description, and the vocabulary in anatomy, but also to construct a new classification of living beings and to pursue a quest for laws of organization. This strategy was successful, since Vicq d'Azyr was able to promote his thought as well as his institutional position efficiently. The Revolution and his untimely death prevented him from achieving his program, but his attempt would serve as an example for younger scientists like Cuvier.