Parameters of neuromuscular system at the unexercised and trained examinees from a position of the theory of chaos and self-organization are studied. Essential distinction between two studied groups (the trained and unexercised students) is established. Dynamics of involuntary micro-movements of extremities (fingers of hands) in a person as reaction to the dosed physical activity is shown in change of parameters of quasiattractors of characteristics of a tremor. Dynamics of increase in volumes of quasiattractors of a vector of organism state in the unexercised students is revealed. The new technique of research of a control system by movements of a person by means of the analysis of characteristics of a tremor of an extremity in the conditions of physical activity is stated. Practical possibility of application of the method of multidimensional phase spaces of involuntary micro-movement in the assessment of reaction of neuromuscular system of the person on dynamic physical activity is shown. As a measure of state of human neuromuscular system (to loading and after loading) the authors use the quasiattractors of movement of state vector of system in two-dimensional phase space of states.