Biomechanical study of the mechanisms of postural adjustment accompanying learned and induced limb movements in cats and dogs.

Trajectories of the center of pressure and center of gravity projections were studied in dynamic conditions during learned movement and movement evoked by the motor cortex stimulation (induced movement) in dogs and cats. The learned movement began with initial displacement of the center of pressure towards the limb performing movement. It corresponded often with initial increasing of the performing limb pressure on support and it was a reason of initial acceleration of the center of gravity in the opposite direction. Induced movement began with decrease of the performing limb pressure on support. It could result in the initial displacement of the center of pressure in the wrong direction but usually it was corrected quickly and the general trajectories of the center of pressure and the center of gravity were similar to ones observed during learned movement. Results suggest different programs for movement and appropriate postural adjustment.