Figure 2.

Characteristics of simple and complex locomotion. A, Schematic drawing of the cat showing monitored spots on the forelimb. B, C, Sequential positions of the right forelimb presented as stick figures for one representative step of simple (B) and complex (C) locomotion; for complex locomotion, the leading limb is shown. The monitored spots are numbered. In C, gray rectangles indicate positions of the two crosspieces of the horizontal ladder.