Postural supporting mechanisms during spontaneous single limb movement in the cat.

Patterns of postural adjustment accompanying spontaneous single limb movement in the cat were studied to examine qualitative and quantitative variations in support strategies. A multiple plate dynamometer and electromyograph were used to measure supporting actions during consecutive trials. Weight transfer involving primarily the forelimbs was dominant. A similar tripodal stance with increased bilateral hindlimb weight-bearing characterized a secondary support strategy. Both dominant and secondary balance behavior showed transient reversals to a bipodal postural pattern. Bipodal stance exhibited increased weight-bearing in the stabilizing forelimb and in the diagonally opposite hindlimb. Selection of different postural strategies for identical phasic limb movements could possibly result from modulation of lower level reflex inhibition.