Biomorphological features of muscles that act on the shoulder joint of some representatives of orderPasseriformes are represented in the article. As shoulder joint of birds has many axes, not only the muscles of the shoulder joint provide the movements in it, but some of the muscles of the shoulder girdle and elbow joint. It should be noted that the main flight muscles of birds are the shoulder girdle muscles, including the chest (m. pectoralis) and supra-coracoid muscles. Some muscles of an elbow joint, including m. coracoradialis and m. scapuli triceps, are equally important. However, the amount of muscles that somehow act on the shoulder joint of the investigated birds' species is different, the degree of muscle development in these species is also different. In order to understand the degree of development, particularly mechanisms of differentiation and development of muscle structures, a comprehensive study of the muscles of the shoulder girdle, shoulder and elbow joints was conducted. The material for the research was obtained from the funds of the Department of animal anatomy named after acad. V.G. Kasyanenko of National University of Life and Environmental Sciences of Ukraine, where the studies of muscular structures of the shoulder joint of some representatives of order Passeriformes, including raven (Corvus corax), rook (Corvus fragilegus), waxwings (Bombycilla garrulous), were conducted. Research of muscles of the shoulder joint, shoulder girdle and elbow joint of birds was performed on fresh or fixed in 10% formalin solution cadavers. After describing and defining of fixation points of the muscles, they were dissected to determine the location of the muscle fibers. In addition, in order to determine the degree of development of muscles and muscle groups, each muscle was weighed. During the research, muscles were drawn or pictured to complement the work with illustrative material. There was no larger or smaller muscle neither in muscle group of shoulder, nor elbow joint that should be significantly for each case. There is no clear stability in the development of muscle groups of these joints. At the same time, muscle group of elbow joint is more developed than the muscle group of shoulder joint. All these mentioned features of structure and differentiation of muscles, which act on the shoulder joint of birds, are caused by physical exertion, posed by adaptation to a different type, speed and duration of flight.
Electromyographic Evaluation of the Shoulder Muscle after a Fatiguing Isokinetic Protocol in Recreational Overhead Athletes
