O volnovoǐ prirode tsentral'nogo protsessa formirovaniia traektorii izmeneniia sustavnogo ugla u cheloveka.

It is supposed that muscles of a single joint are controlled by a wave propagation of excitation along a central line-ordered neuronal ensemble. The number of steady active output ensemble neurons increases with wave-front displacement and the neurons discretely contribute to the motor command that is defined in terms of shifts of the so-called invariant muscle force-length characteristics. The terminal position of the wave front is responsible for the final angular limb position, whereas the wave velocity responsible for the peak movement speed. To verify the wave model, human time-angle trajectories of rapid arm movements to different positions in the horizontal plane were analysed. The trajectories fall into groups having the following properties: 1) The initial profiles of the trajectories that belong to one group are identical; 2) the duration of the coincidence of any two grouped trajectories increases with their extent; 3) summation of two or more grouped trajectories with a certain time delay between them again gives a trajectory which belongs to the same group. The data obtained are in good agreement with the wave model.