Femoral Variability on the Plateau of North America

The purpose of this research is to examine femoral variation within the Plateau region of North America by using external measurements. Femoral measurements from the Northern and Southern regions of the Plateau were analyzed for temporal and spatial changes in femur shape associated with a change a from hunter-gatherer lifestyle in the prehistoric period to a more sedentary lifestyle in the historic period. Results indicate that there is no significant variation between the Northern and Southern Plateau samples. Results do, however, indicate that there are differences in the femoral measurements of prehistoric and historic populations. Changes in femoral size are very significant in the maximum diameter of the head, and differences are somewhat evident in the following measurements; midshaft mediolateral diameter, trochanteric length, and femur midshaft diaphyseal shape. Historic populations have a larger femoral head diameter, and tend to have shorter, wider (mediolaterally at midshaft) femora. While prehistoric populations tend to have a longer femora that is anteroposteriorly elongated at midshaft. These differences may reflect changes in the mechanical loads placed on the femur during the highly mobile prehistoric period and the increasingly sedentary historic period.