Lower limb biomechanics and habitual mobility among mid-Holocene populations of the Cis-Baikal

The mid-Holocene hunter-gatherer populations of the Cis-Baikal represent long-term occupation by the Early Neolithic Kitoi Culture (6800-4900 B.C.) and the Middle Neolithic and Bronze Age Isakovo, Serovo and Glazkovo (ISG) cultures (4200-1000 B.C.). While there is considerable evidence for cultural and genetic discontinuity between these populations, differences in habitual activity between these periods remain poorly understood. The current study uses cross sectional geometric (CSG) properties of the femur and tibia in the lower limb, to investigate variation in mechanical loading and terrestrial locomotion between the Kitoi and ISG cultural groups. The results demonstrate a significant decrease in femoral rigidity and a trend towards more circular femoral diaphyses among the later ISG groups which suggests that there was a significant decrease in terrestrial mobility across this transition. This trend is accompanied by significant declines in tibial rigidity among females, resulting in greater sexual dimorphism among the ISG than the Kitoi. This indicates a shift towards a sexual division of labour which involved greater sedentism of the ISG than Kitoi women. Overall, the results suggest that shifts in habitual activity throughout the mid-Holocene of the Cis-Baikal involved both increased sedentism, and an increase in sexual differences in logistical mobility.