Simulation studies of descending and reflex control of fast movements

Several neurological control strategies for fast head movements are considered using computer simulations of a stretch reflex model. Each control strategy incorporates a different amount of proprioceptive feedback contributing to braking and/or clamping the movement. The model behavior for each control strategy is qualitatively compared to experimental data that includes the agonist and antagonist EMGs, and the head position, velocity, and acceleration. Significance of the study is discussed with respect to the characteristic tri-phasic EMG pattern for fast voluntary movements and the possible roles that the stretch reflex may have in contributing to this pattern of activation.