Anatomical evidence for a uniquely positioned suprascapular foramen.

The suprascapular foramen is a rare but not exceptional variation of the suprascapular notch. The suprascapular notch and suprascapular foramen could lead to pain and muscles atrophy because of nerve compression. In this study, we present a suprascapular foramen which does not correspond to a nerve's trajectory but rather corresponds to a specific bone formation that increases the surface area for muscle attachment. As a consequence, its presence cannot be taken as an indication for neurolysis, contrary to ossification of the foramen in its normal anatomical position. Moreover, this unique foramen is distinguishable from a classical suprascapular foramen on radiographs and, especially, on CT scan images.

A pathological Neandertal thumb phalanx from Moula-Guercy (France).

OBJECTIVE: To discuss a Neandertal pathological adult first pollical proximal phalanx (I2-104) from the Baume de Moula-Guercy (Ardèche, France) and evaluate the possible causes of this pathology. METHODS: Macroscopic analyses of external features, as well as CT imaging, were used in the analysis RESULTS: The presence of asymmetric eburnation on the distal epiphysis associated with an osteophyte on the palmar surface, as well as the absence of periosteal bone reaction visible on CT images, is consistent with osteoarthritis. CONCLUSION: Osteoarthritis (OA) can have different origins and the cause is difficult to identify. The pathology of the Moula-Guercy I2-104 phalanx may be due to a genetic predisposition for OA known in Neandertals and associated with short limb bones. The OA could have been aggravated by the age of this individual and by an inflammatory reaction caused by repeated movements and intense vibrations provoked by high-frequency knapping or by other use of the hands SIGNIFICANCE: The I2-104 phalanx is the first Neandertal pollical phalanx known to display OA, although joints of this bone are frequently affected by this pathology in modern humans. Thus, greater insight into the presence and consequences of Neandertal behaviors is offered LIMITATION: It is impossible to give a definitive conclusion on the cause(s) of the OA in this case. SUGGESTIONS FOR FURTHER RESEARCH: More data is needed concerning OA within Neandertals and its relationship with behavior and genetics.

Revisiting the question of Neandertal regional variability: a view from the Rhône valley corridor.

We compared the dental assemblage of the Rhône Valley corridor (RVC) with that of European Neandertals dating to MOIS 7-4 using two linear measurements and three indices. To test if the RVC population was significantly different from Western European Neandertals, we preformed a multi-tiered approached. First, we tested for the normality of the variables using a Shapiro-Wilks test. If the variables were normal, a stepwise Discriminant Function Analysis (DFA) (using Mahalanobis distances) was performed for the normally distributed variables. DFA uses correlation metrics to address weight combinations of variables and emphasizes between group variation while minimizing within group variation. Results show that there is no distinction between the RVC population and other Neandertals except for the Crown Module index of the upper canine. However, the presence of a single significant result does not provide evidence for a local RVC variant within the Neandertal population. These results are supported by evidence from archaeological analysis of this region. We propose that the high genetic control for dental size and shape may account for the reduced ability to distinguish between subpopulation groups based on dental dimensions in groups with small effective size such as the Neandertals.

Clavicle, a neglected bone: morphology and relation to arm movements and shoulder architecture in primates.

In spite of its importance for movements of the upper limbs, the clavicle is an infrequently studied shoulder bone. The present study compares clavicular morphology among different extant primates. Methods have included the assessment of clavicular curvatures projected on two perpendicular planes that can be assessed overall as cranial and dorsal primary curvatures. Results showed that in cranial view, three morphologies can be defined. One group exhibited an external curvature considerably more pronounced than the internal one (Gorilla, Papio); a second group was characterized by an internal curvature much more pronounced than the external one (Hylobates, Ateles); and a third group contained those with the two curvatures equally pronounced (Pan, Homo, Pongo, Procolobus, Colobus). Clavicle curvatures projected on the dorsal plane could be placed into four groups. The first group is characterized by two curvatures, an inferior and a superior (Apes, Spider monkeys). The second included monkeys, whose clavicles have an inferior curvature much more pronounced than the superior one. The third group includes only Hylobates, whose clavicles possess only the superior curvature. The last group includes only modern humans, whose clavicles show only the inferior curvature, which is less pronounced than that which exists in monkeys. Curvatures in cranial view relate information regarding the parameters of arm elevation while those in dorsal view offer insights into the position of the scapula related to the thorax. The use of clavicular curvature analysis offers a new dimension in assessment of the functional morphology of the clavicle and its relationship to the shoulder complex.

The Omo I hominin clavicle: archaic or modern?

Assessment of clavicular curvatures projected onto two perpendicular planes to decompose the three dimensional shape into cranial and dorsal primary curvatures has shown that two morphological groups of clavicle exist within the genus Homo. The first one includes all species from Homo habilis to Neandertals, while the second includes only Upper Paleolithic remains and more recent modern humans. These morphological differences are associated with different shoulder architectures. The morphology of the Omo I left clavicle is sufficiently complete to compare its curvatures to other clavicles of several species of Homo. Its overall morphology, assessed by its curvatures, is similar to that of Upper Paleolithic remains and modern humans, confirming the conclusions of previous descriptions of the Omo I remains in general and of its clavicles in particular.