 The length ratio of her humerus (arm) to femur (thigh) is 84.6%, which compares to 71.8% for modern humans, and 97.8% for common chimpanzees, indicating that either the arms of "A. afarensis" were beginning to shorten, the legs were beginning to lengthen, or both were occurring simultaneously.Lucy also had a lordose curve, or lumbar curve, another indicator of habitual bipedalism.She apparently had physiological flat feet, not to be confused with pes planus or any pathology, even though other "afarensis" individuals appear to have had arched feet.