As an essential organ of both weight bearing and locomotion, the spine is subject to the conflict of providing maximal stability while maintaining crucial mobility, in addition to maintaining the integrity of the neural structures. Comparative morphological adaptation of the lumbar spine of mammals, especially in respect to locomotion, has however received only limited scientific attention. Specialised features of the human lumbar spine, have therefore not been adequately highlighted through comparative anatomy. Mathematical averages were determined of 14 measurements taken on each lumbar vertebrae of ten mammalian species (human, chimpanzee, orang-utan, kangaroo, dolphin, seal, Przewalski's horse, cheetah, lama, ibex). The revealed traits are analysed with respect to the differing spinal loading patterns. All examined mammalian lumbar spines suggest an exact accommodation to specific biomechanical demands. The lumbar spine has reacted to flexion in a predominant plane with narrowing of the vertebral bodies in quadrupeds. Torsion of the lumbar spine is withstood by an increase in the transverse distance between the inferior articular processes in the upper lumbar spine in primates, but lower lumbar spine in humans, quadrupeds and the seal. Sagittal zygapophyseal joint areas resist torsion in the seal and humans. Ventral shear is resisted by frontal zygapophyseal joint areas in humans and primates, and dorsal shear by encompassing joints in the ibex. The human fifth lumbar vertebra is remarkable in possessing the largest endplate surface area and the widest distance between the inferior articular processes, as an indicator of the high degree of axial load and torsion in bipedalism. Anat Key words: lumbar spine; zygapophyseal joints; comparative anatomy; mammalian; human; locomotion; bipedalism; gaitDue to the high incidence of spinal disorders, the human lumbar spine has maintained the stigma of being inadequately adapted to upright posture and locomotion. The converse point of view (Putz and Mü ller-Gerbl, 1996), however, suggests an exact accommodation of the spine of each mammalian species, including humans, to the specific biomechanical demands of the course of evolution, maintaining maximal stability while granting ideal mobility and securing the protection of neural structures. To date, the published literature on comparative lumbar vertebral anatomy has focused either on singular morphological aspects or selectively upon a mammalian subgroup

Until now, it has been taken for granted that the point of emergence of the supraorbital nerve is by way of a notch or a foramen at the border of the inner to the medial third of the supraorbital rim. In contrast to several anatomic textbooks, we noticed that the exit point was repeatedly not at the site where anticipated when implanting lid springs for facial palsy. This gave us the idea of investigating these variations and how big they are, because most open and recent endoscopic forehead lift techniques have relied on a constant exit point of the supraorbital nerve. A total of 507 macerated skulls (1014 orbits) from three anatomic collections in Austria and Germany were studied. All skulls were adult European skulls gathered from the prehistoric age up to the twentieth century. Additionally, 18 fixed cadavers (36 orbits) and 25 fresh cadavers (50 orbits) were studied. These data were not included in the statistical analysis but in the discussion. The anatomic measurements on the skulls were carried out with an anthropometric calliper. The examinations concentrated on the configuration (notch/foramen) and the number of exit point(s) on the supraorbital rim, the vertical distance from the supraorbital rim, and the distance from the nasion to the various exit point(s). Combining all of these parameters, 74 percent of the skulls showed asymmetric findings between the right and left orbits. In 15 percent of both orbits, the supraorbital nerve left the orbital cavity already in its two branches, the medial and lateral branch, either through a notch or a foramen, the foramen being sometimes the exit of a supraorbital canal. The average distance from the nasion to the frontal notch/foramen was 25 mm on both orbits (range 16 to 55 mm) and to the supraorbital notch/foramen 31 mm (range 20 to 49 mm). The largest vertical distance from the supraorbital rim to its farthest exit point was 19 mm. Other than what is cited in literature, the variations concerning the configuration and the distance of the exit point(s) of the supraorbital nerve were so significant that all forehead operations, especially those using endoscopic techniques, must take into account these findings.

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This investigation is based on measurements of 60 macerated adult European skulls from the Alexander-Ecker Collection at the Anatomy Department of the University of Freiburg. Computer tomographical (CT) and anatomical measurements were compared to assess the accuracy of the CT representation of osseous structures. Nine structures were examined: the optic canal; the superior orbital fissure; the foramen rotundum; the foramen ovale; the foramen spinosum; the foramen Vesalii (venosum); the carotid canal; the internal auditory canal, and the hypoglossal canal. The results show a good and even excellent correlation if the cranial opening is approximately at a right angle to the scanline. For this reason, the results of the coronal examination of the internal auditory canal are less satisfactory, and the coronal and axial measurements of the hypoglossal canal show only a moderately good correlation.

Human cadaveric specimens commonly serve as mechanical models and as biological tissue donors in basic biomechanical research. Although these models are used to explain both in vitro and in vivo behavior, the question still remains whether the specimens employed reflect the normal in vivo situation. The mechanical properties of fresh-frozen or preserved cadavers may differ, and whether they can be used to reliably investigate pathology could be debated. The purpose of this study was to therefore examine the mechanical properties of cadaveric long biceps tendons, comparing fresh (n=7) with fresh-frozen (n=8), formalin embalmed (n=15), and Thiel-preserved (n=6) specimens using a Universal Testing Machine. The modulus of elasticity and the ultimate tensile strength to failure was recorded. Tensile failure occurred at an average of 12N/mm in the fresh group, increasing to 40.1N/mm in the fresh-frozen group, 50.3N/mm in the formalin group, and 52N/mm in the Thiel group. The modulus of elasticity/stiffness of the tendon increased from fresh (25.6MPa), to fresh-frozen (55.3MPa), to Thiel (82.5MPa), with the stiffest being formalin (510.6MPa). Thiel-preserved and formalin-embalmed long head of biceps tendons and fresh-frozen tendons have a similar load to failure. Either the Thiel or formalin preserved tendon could therefore be considered as alternatives for load to failure studies. However, the Young's modulus of embalmed tendons were significantly stiffer than fresh or fresh frozen specimens, and these methods might be less suitable alternatives when viscoelastic properties are being investigated.

According to current generally accepted theories, analysis of the shape of a bone provides clues to the stresses acting upon it. Although many investigations have ensured that understanding of the lower limb is relatively advance, knowledge relating to the upper limb, and particularly to the scapula, is still far from complete. We have therefore endeavoured to interpret the shape of this bone morphometrically. To this end various scapular parameters have been standardised and statistically analysed, and the results examined both from the functional and the clinical points of view. Our investigation has established that, as in the case of the long bones, the form of the scapula is dependent upon both height and sex. Assessment of the architecture of the subacromial space and its possible parameters of influence have also demonstrated that the size of this space is essentially dependent upon the height of the subject and the size of the acromial and scapulospinal angles. A short distance between the acromion and the upper edge of the glenoid cavity and a small glenoid-spinal angle can be regarded from a functional point of view as factors predisposing to the development of the impingement syndrome. We have also been able to show that certain constant structural features produce an optimal distribution of the forces acting upon the scapula. In particular, the relationship of the supporting pillars (the lateral border and the spine) of this bone to one another appears to represent the expression of an ideal adaptation to the action of those forces.

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In this study, the ligaments of the ankle joint and the tibiofibular syndesmosis were examined in formalin-fixed anatomic specimens using a 13 MHz sonographic scanner. For this purpose, 48 specimens of the ankle joint were examined, and the anterior tibiofibular, anterior talofibular, and calcaneofibular ligaments were marked by sonographically guided dye injection. The markings were checked during the subsequent dissection. The number of identifications reached 89.6% for the anterior tibiofibular and talofibular ligaments and 87% for the calcaneofibular ligament. The results show that the most frequently injured ligaments of the ankle joint can be visualized reliably by use of 13 MHz high-frequency sonography.