A Biomechanical Interpretation of the Pelvis of Australopithecus

TLDR

Dart’s model of the Makapan ilium in a Bushman pelvis revealed morphological similarities in size and shape, and the evolution from Australopithecus to Homo favored improved joint motion elements essential for hunting, gathering, and tool use rather than a specific gait. These features relate to the ability of the anterior gluteus medius–minimus muscle complex to produce internal rotation. Structural differences of the ilia imply that internal rotation, together with abduction, is a fundamental motor element for efficient bipedal gait, giving the gluteus medius–minimus complex important survival value.

Abstract

Dart’s model of the Makapan ilium in a Bushman pelvis showed their morphological similarities in size and shape. The structural differences of the ilia have important implications for locomotion that are revealed by biomechanical reconstruction. These features relate to the ability of the anterior of the gluteus medius-minimus muscle complex to produce internal rotation. Combined with abduction, internal rotation is a fundamental motor element necessary for efficient bipedal gait; consequently, the muscle complex had important survival value. In the evolution of Australopithecus to Homo , selection was less for a particular gait than for the improvement of a joint motion element in gait as an essential part of a hunting/gathering and tool-using way of life.