Fig. 1. Summary of the commonly accepted differences that are believed to distinguish the walking gaits of most primates from those of most nonprimate mammals. Nonprimates generally use (A) lateral sequence walking gaits (LH, RH, left and right hindlimb; LF, RF, left and right forelimb), (B) have a humerus that at ground contact is retracted relative to a horizontal axis passing through the shoulder, and (C) have greater peak vertical forces F on their forelimbs than they do on their hindlimbs. Primates show the opposite pattern. From Schmitt and Lemelin (2002), with permission.