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Introduction: The basic function of the hand is prehension. The muscles of the forearm involved in prehension, the flexors and extensors of the wrist and fingers, attach at the epicondyles of the humerus, at the radius and ulna. Overstrain causes epicondylar pain. The cause of this phenomenon is passive insufficiency of muscles spanning several joints, in this case of the flexor digitorum profundus of the upper extremity, held in extension.Aim: To explore insufficiency of muscles electromyographically.Method and results: Activity of the flexors and extensors of the forearm was registered by surface electromyography, and this showed reduced activity when flexion of the end-phalanges was caused only by passive muscular insufficiency.Conclusion: These observations prove that carrying objects by the flexed end-phalanges keeping the muscles of the forearm relaxed is important for treatment and prevention of epicondylar pain. There is, however, an exception in extremely hypermobile subjects.

Development of the frontoparietal bone in the European yellow-bellied toad, Bombina variegata, was followed on the basis of histological analysis of transverse serial sections through the larval skulls to recognize early stages of ossification represented by osteoid (uncalcified bone matrix) and on cleared and stained specimens to investigate more advanced stages. Ossification of the frontal begins as three tiny areas of osteoid (F1, F2, F3) adjoining the dorsal surface of the orbital cartilage, which are separated by areas without osteoid. F3 is the largest (most advanced). Prior to calcification, F3 extends to fuse with F2 and then with F1, but it does not expand over the prootic fissure posteriorly. As calcification begins the strip of bone is joined posteromedially by F4. Only then does a single ossification center corresponding to the parietal arise on the anterodorsal surface of the otic capsule. This ossification sequence corresponds to those observed in the Actinopterygii and in caudate amphibians. J. Morphol. 255:122–129, 2003. © 2002 Wiley-Liss, Inc.

The tissues are during their physiological function, e.g., in the course of growth, adolescence, and aging, subjected to a cyclic mechanical loading and to large displacements and rotations as well. A tissue free of all external tractions is in a state that minimizes its internal power. In the course of aging of the tissues, for instance in the wall of the aorta, the vein, and also in the myocardium or heart valves, the decrease of the water content and increase of the collagen content occurs; while in compact and trabecular bone the contents of both mineral substances and collagen, undergo reduction. In accordance with it, the strain energy function and the constitutive equations of living tissue based on the hyperelasticity theory using rotationless strain were studied. On the base of the proposed eigenvalue decomposition of the rotationless strain tensor and hyperelasticity the strain energy function was formulated as depending on biological time of tissue. The quantity of strain energy function per unit of the biological time, which essentially characterizes the velocity of change of mechanical response of tissue in the course of its aging, was also defined. The coefficient of tissue aging is the further diagnostic parameter, which is independent of the rotationless strain tensor and expresses the relative change of mechanical response of tissue during the biological time. The corresponding constitutive equation of tissue depending on the biological time is also determined. On the base of the regression analysis the theoretical stress-strain curves for myocardium and blood vessels were determined. The numerical results reveal that the coefficient of aging progressively increases in hardening tissues (coronary artery, vena cava inferior) whereas at the softening tissues it has a relatively slow increase at the dependence on tissue aging.

From the beginning of this century when Lewis (1901/02, 1910), Bardeen and Lewis (1901) and Bardeen (1906/07) published their impressive illustrations of embryonal muscles, obtained by plastic reconstructions from serial sections and when Grafenberg (1905/06) brought the descriptions of stages of muscle development, it has generally been accepted that limb muscles undergo a “direct” or a “straight up” differentiation in their ontogenesis. This means that every one muscle primordium separates from the larger blas-tema, i.e. from the premuscular mass for flexors or extensors, already in its form and position corresponding to the definitive muscle.

The fundamental question concerned in developmental studies of hand and foot muscles is that of the origin and homologies of the muscle layers. The attempts at classification and homologisation of palmar muscle layers appeared in the literature a long time ago.

The question of the origin, derivation and homologies of carpal and tarsal components has been an onerous problem in developmental anatomy for more than a hundred years. Interest was evoked by the work of Gegenbaur (1865) where the structure of the tetrapod extremity was derived for the first time from the fin of elasmobranch fishes. In the course of the subsequent development of the problem this idea was gradually exactified and geometrised (Gegenbaur, 1870a, b, c, d). Less known in the history of the problem, but quite important for later views on the development of the extremities is Gegenbaur’s consideration of the uniserial “archipterygium ” as the elemental extremity type, presented in these early works. From the archipterygium he derived the five-toed extremity so that he at first located the main axis through the radius and the fifth finger and derived the remaining fingers as collateral rays (Fig. 1 A). Later on, influenced by Huxley’s criticism (1873), Gegenbaur (1876) transposed the main extremity axis into the ulnar margin of the uniserial archipterygium and other fingers again were derived in the form of collateral rays.

The aim of the present work is to demonstrate of the influence of the adventitia on distribution of residual stresses in the human aorta. The biomaterial increase in media as well as in adventitia in the course of the aorta's growth is formed by an intussusceptive mechanism of growth. In children's aortas, formative elastin lamellae are wavy with high amplitude perpendicular to the aortic surface. In adults' aortas the waves become smoother (stepwise) towards the adventitia. Also introduced is the growth function, which characterizes the biomaterial growth and the interference between the media and adventitial layers. It is possible to expect an extraordinary variability in the formation of the aortic wall tissue in the course of its growth as a result of metabolic and humoral influences and magnitude of the residual stresses in the course of growth.