Spatial-Temporal Structure Features of Muscle Synergies during Profiling Elements Implementation in Rhythmic Gymnastics

The article presents an analysis of the muscle synergies involvedin making ball throws in different directions and from differentstarting positions. The study involved 6 highly qualified athletesengaged in rhythmic gymnastics. Electromyograms of the superficialmuscles of the upper extremities and trunk were recorded synchronouslyduring the movements, as well as video capture of the movementsof body segments. Synergy parameters were extracted from the recordedsignals using factor analysis using the principal component method.It has been established that individuals who have mastered a complex motorskill can demonstrate similar motor control strategies. This ismanifested in the structuring of intermuscular interaction in theform of two general modules, the degree of involvement of musclesin which is highly similar in the implementation of different motortasks. The first muscle module implements active movement of theupper limb by jointly activating the muscles of the forearm, shoulder andupper shoulder girdle, and also provides stabilization of the positionof the trunk by synchronizing the activity of the muscles of theback and abdomen. The second muscle module is specific and is mainly associatedwith high involvement in the synergy of the muscles of the uppershoulder girdle and forearm for the implementation of exercisesperformed without visual control, or from starting positions that limitthe mobility of certain parts of the body. Thus, the solution tothe problem of coordination of many elements of the motor systemmay consist not only in reducing the number of executive organs—muscles involvedin control, but also in organizing control variables in the formof modules at the kinematic level and their stabilization throughmuscle synergies.