Homo erectus has special body features that enable them to be bipedal. The most critical factor determining the bipedalism of Homo erectus is their pelvis morphology (Gruss & Schmitt, 2015). The pelvic of Homo erectus contributes to the length of their through rotation of the pelvis when running. The rotation allows for the increment of the stride legs’ swing without necessarily lowering the body mass, resulting in heavy muscle exertion. Besides, the enlarged pelvis of Homo erectus makes it ideal to be bipedal because the modified pelvis helps resist the stress associated with running. The pelvis modification, called the iliac pillar, also plays a crucial role in preventing stress from running. On the other hand, the wide femora also give room for maximum mechanical advantage, especially for the muscles that bring legs towards the midline.
In Australopithecus apheresis, the pelvis’s width affects the muscular requirement necessary for running (Schulkin, 2016). When one leg supports the body, the Australopithecus apheresis tends to fall off from the supporting leg limiting its ability to run. Australopithecus apheresis had a tall waist and broad thorax like pelvis than in Homo erectus. There is a strong connection between the pelvis and the spine as the two work together to achieve stability. Therefore, the thinner the pelvis, the more the stability; one thing that the Australopithecus apheresis lacked. Thus, this contributed to their lack of bipedalism, unlike Homo Erectus.
Endurance running is a form of continuous running over long distances repeatedly for an extended period. When the homo genus carries out enduring running, the tendons and ligaments in the legs act as springs push forward and backward, strengthening the body. Continuous endurance running makes them strong as the muscles adjust to the tough conditions they have been subjected to.