The bone also shows that A. afarensis had abandoned the flexible midfoot that apes use to grasp tree branches, in favor of an arch that makes upright walking more efficient.

这个骨头也说明南方古猿已经抛弃了猿所具有的用于攀爬树枝的柔韧的足中段结构，由于足弓结构的出现，直立行走变得更有效率。