Fig. 6. Cockroaches (A,B) and geckos (C,D), with different leg number, morphology and adhesive mechanism, have similar single-leg wall reaction force patterns during climbing. Dorsal (A,C) and sagittal (B,D) views are shown. The arrows represent average peak wall reaction forces for single legs in fore-aft (blue), lateral (green) and normal (red) directions. All legs in both animals pull up the wall. Legs pull in toward the midline, except for the hind cockroach legs where lateral forces were near zero. Front legs pull the head toward the wall, while hind legs push the abdomen (below the COM) away from the wall. In the cockroach, the middle-leg normal forces were small. Black arrows indicate average body weight for the animals studied (30 mN for cockroaches, 20 mN for geckos). Arrows that represent limb reaction forces are scaled relative to the length of the black arrows. Gecko data are from Autumn et al. (2006).