Shod versus unshod: The emergence of forefoot pathology in modern humans?

BackgroundPathologies of the metatarsal bones in contemporary humans are common yet it remains unclear from an evolutionary perspective to what extent, if any, footwear and other environmental factors such as modern substrates have contributed to the emergence of common metatarsal pathological changes.ObjectivesTo investigate the frequency of metatarsal bone pathologies in contemporary and habitually unshod pre-historic people in order to ascertain whether these frequencies are affected by variation in habitual behaviour, the wearing of footwear and/or exposure to modern substrates.MethodThe metatarsal elements from four human groups were examined for pathological variation. Three of these skeletal samples were from recent rural and urban shod populations (Sotho, Zulu and European) and one from habitually unshod pre-pastoral Holocene people who practiced a subsistence hunter gatherer lifestyle.ResultsThe trends in the dominance of pathological lesions between the five metatarsal bones were broadly similar in all four samples. In all groups the first metatarsal presented with the greatest number of pathological lesions; more specifically, at the first metatarsal head. The Sotho and European groups presented with notably greater frequencies of pathological changes followed by the Zulu group and then the pre-pastoral.ConclusionsThe pathological lesions found in the metatarsals of the three recent human groups generally appeared to be more severe than those found in the pre-pastoral group. This result may support the hypothesis that pathological variation in the metatarsus was affected by habitual behaviour including the wearing of footwear and exposure to modern substrates.