An Osteometric Study on the Variation in Orientation of the Lesser Trochanter in an Early Medieval Human Skeletal Assemblage and Comparison with an Individual from the Late Upper Palaeolithic

Abstract

Anatomical textbooks describe the lesser trochanter in contemporary humans as being oriented posteromedially. In contrast, orientation of the lesser trochanter towards posterior was observed in some human femora from the Upper Palaeolithic, including the femur of a young adult individual from Germany (Irlich 1), radiocarbon dated to 12 500-11 200 BP (calibrated AMS age). The present study analysed the orientation of the lesser trochanter in femora originating from an early medieval skeletal assemblage (Greding, Germany) and compared the results with those for the Irlich 1 femur. Eleven landmarks, four on the proximal femur, four on the mid-shaft and three on the distal femur, were recorded with a MicroScribe® digitizer and analysed using AutoCAD® 2010 software. Seven angles and five distances were measured. In the Greding femora, significant differences (p < 0.05) between sexes were found for several linear measurements, while no significant sex-related differences existed for angular measurements. For some angular variables related to the orientation of the lesser trochanter, the values for the Irlich 1 femur lay outside the range of variation of the Greding specimens, reflecting the more posterior orientation of the lesser trochanter in the Irlich 1 femur. This posterior orientation of the lesser trochanter was not associated with a particularly low degree of femoral anteversion. It is hypothesised that the differences in orientation of the lesser trochanter between the Irlich 1 femur (and other femora of Upper Palaeolithic individuals) and the femora from Greding could basically reflect differences in traction exercised by the iliopsoas muscle during infancy and childhood between the sedentary agricultural population from Greding and Upper Palaeolithic hunter-gatherers with a mobile lifestyle.