COMPARATIVE ELECTROMYOGRAPHIC ANALYSIS OF DIFFERENTLY-SKILLED DANCERS' MOVEMENTS

Sport dancing is a hard-house type of sports, so dancers at the first classes face a variety of movements, which differ in amplitude, direction, speed, and different combinations at different times and different directions of movements of body parts. All this diversity must be implemented within strict spatial and temporal parameters, within the rhythmic picture of a dance. To form a skill of managing their dance moves dancers need a special motor training. To optimize the management of the process of such motor trainings a theoretical and experimental study must be conducted of criteria of objective control of dance movements. In analyzing the data we found mixed results of bioelectric parameters of right and left rectus muscles of thighs among highly skilled dancers. We observed that when performing the basic dance movement "time-step", the maximum amplitude contraction of rectus muscles of the left thigh of young men is significantly higher than that of girls. The maximum amplitude contraction of rectus muscles of the right thigh of girls is higher in comparison with boys. Similar results of the priority of the "take-off" leg according to the gender were also detected among secondary indicators: the mean and total amplitudes and mean frequency of rectus muscles contraction. Apparently, these figures are associated with the specifics of the dance sport: when performing the competitive variation of a duet dance the he-partner usually begins with the right foot, while loading the left, and the she-partner, respectively, starts with the left one, while loading the right leg. Our data are consistent with the studies on the speed of motor reaction of dancers at the audio signal. The authors have noted the fact of priority of the "leading hand" in the tactile interaction of the dancing duet, also associated with the specific of the sport. In addition, we found a reduced period of electrical activity of muscles in the group of highly-skilled dancers. Obviously, this is due to the decrease of time necessary to perform a movement, as it increases the synchronization of motor fibers (by average frequency) and, as a result of this, the period of electrical activity reduces. Consequently, it is the nature of bioelectric indicators of rectus muscles of thighs that determines the level of special motor preparedness in the sport dance. The higher the skill level of dancers is, the more noticeable the difference in the amplitudes and mean frequency of performance in seconds.