Anthropology, University at Albany
Saturday All day, Plaza Level
Traditionally, analyses of femoral morphology have examined the effect of skeletal variables on structural integrity separately, an approach that does not incorporate information on the whole bone. Finite element analysis allows exploration of the structural integrity of complete Neanderthal and recent modern human (RMH) femora in order to obtain a detailed picture of precisely how the characteristic differences between these femora affect their strength and strain predictability, while taking into account loading patterns produced by differences in the configuration of hip and knee joints. Finite element models of femora of a Neanderthal and RMH were used to investigate how differences in antero-posterior curvature, neck-shaft angle, diaphyseal cortical bone thickness, and transverse cross-sectional shape affect strength and predictability of strain distribution during three scenarios typically encountered during locomotion: 1) the moment of peak body weight transmission during regular bipedal walking, 2) irregular steps, and 3) traumatic force impact.
Six experiments were conducted, three assessing strength and predictability incorporating size and shape information, and three using isometrically scaled forces such that only shape differences are evaluated: the first two experiments mimicked normal bipedal walking, simulated at the moment of peak acetabular contact force (314.8% body weight) during the stance phase of gait. The second two explore the consequences of an irregular step, such as a stumble and were simulated as double the value of peak acetabular contact force oriented at an altered angle. Lastly a traumatic load was simulated by the application of a horizontal force (500 N) directed toward midshaft.
This study is funded by the National Science Foundation, grant number 1094672-1-57430.