Different Types of Muscle Contraction Regulation in Athletes Adapted to Stereotypical and Situational Motor Activity

Resumo

We studied the regulatory mechanisms underlying isometric and concentric muscle contractions in athletes adapted to stereotypical and situational motor activities. It has been found that the total electromyography (EMG) amplitude of the studied muscles in basketball players during isometric and concentric contractions to voluntary failure in the final period (phase) of contractions decreases, as compared with the initial phase, while the EMG amplitude in short- and long-distance runners was more stable throughout the whole contraction duration. This EMG dynamics was accompanied by certain changes in the amplitude and frequency of EMG turns, confirming that electrical activity in the motor units of muscles is differently organized in basketball players and runners. The coordination structure of the performed isometric and concentric contractions is probably determined by the specificity of the motor program pool formed in athletes during their adaptation to different types of training.