The anomalous archaic Homo femur from Berg Aukas, Namibia: A biomechanicalassessment

The probably Middle Pleistocene human femur from Berg Aukas, Namibia, when oriented anatomically and analyzed biomechanically, presents an unusual com bination of morphological features compared to other Pleistocene Homo femor a. Its midshaft diaphyseal shape is similar to most other archaic Homo, but its subtrochanteric shape aligns it most closely with earlier equatorial H omo femora. It has an unusually low neck shaft angle. Its relative femoral head size is matched only by Neandertals with stocky hyperarctic body propo rtions. Its diaphyseal robusticity is modest for a Neandertal, but reasonab le compared to equatorial archaic Homo femora, Its gluteal tuberosity is re latively small. Given its derivation from a warm climatic region, it is bes t interpreted as having had relatively linear body proportions (affecting p roximal diaphyseal proportions, shaft robusticity, and gluteal tuberosity s ize) combined with an elevated level of lower limb loading during developme nt (affecting femoral head size and neck shaft angle). (C) 1999 Wiley-Liss, Inc.