Moscow University
Anthropology
Bulletin
Anthropology
Bulletin
1) Moscow state academy of veterinary medicine and biotechnology named K.I. Skryabin, Moscow; 2) Lomonosov Moscow State University, Faculty of biology, Department of anthropology, Leninskie Gory, 1, p.12, Moscow, 119991, Russia
Vlasenko A.N., e-mail: dragprechvan@mail.ru; Drobyshevsky S.V., e-mail: dsv_anth@mail.ru
Biomechanical capabilities of the glenohumeral joint and coordination brain capabilities of anthropoid primates don’t except the ability to throw objects accurately, however, in comparison with human being this potency realizes feebly. In this article different causes of the throwing abilities of apes and human beings, which lie in specialization of the articular surface of the articular cavity of the scapula and the head of a humeral bone of modern human and Neanderthal, are considered. The research was done with the materials of Sub-Faculty of Anatomy and Histology of Moscow state academy of veterinary medicine and biotechnology named K.I. Skryabin, Anthropology Department and Zoological Museum of MSU. Mammal skeletal material over 29 species was used. The curvature of articular surfaces was measured. Simulation modeling of movement, corresponding to throwing one was practicing on skeletal material and volunteers; movement trajectory was fixed with the help of photography. The videorecordings of the trainings and performances of the javelin-throwers were also analyzed. The shape of the articular surface of scapula is sharply different between animals, adapted to the different forms of locomotion: the articular surface of terrestrial interacts between themselves during extension «forced trajectories» way, which limit lateral and rotatory motions; arboreal’s glenohumeral joint allows more free movements; brachiator’s surfaces are perfectly spherical. We discovered a unique specialized variant in human’s and Neanderthal’s joint with subdivision of the articular surface into two zones. One of the zone is the cause of the «forced trajectory», which promotes throwing movements and makes them more clear. Archeological testimonies allow to suppose, that morphofunctional throwing complex of the glenohumeral joint began to form 3,5 millions years ago and had been developed about 600 thousand years ago (as minimum). Quadrupedal mammals’ erratic curvatury of the articular surface of the head of the glenohumeral bone and glenoid determines «forced trajectory» while extension of glenohumeral joint and points the specialization of biological species in making rectilineal motions of a thoracic limb. Unlike the quadrupedal mammals humans’ specific changes of the relief of the conjugated surfaces of the glenohumeral joint, which determines the «forced trajectory» of the flexion-extention movement had developed not as an adaptation to walking or running, but as morphic adaptation to throwing objects into the goal. The characteristics of the articular surface of the humans’ glenohumeral and scapular bone can be considered one of the ancestral features and can be used in paleontology as a marker for humans’ differentiation from anthropoid apes, adapted to wooden locomotion and perhaps from the early orthograde hominids.
human morphology, anthropology, human origin, shoulder joint, scapula, humerus, throwing, Neanderthals
Цит.: Vlasenko A.N., Drobyshevsky S.V. What determines the accuracy of the throwing? «Forced trajectory» in the movement of the shoulder joint // Moscow University Anthropology Bulletin (Vestnik Moskovskogo Universiteta. Seria XXIII. Antropologia), 2016; 1/2016; с. 46-53
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