Revisiting traumatic injury risk and agricultural intensification: Postcranial fracture frequency at Cerro Oreja in the Moche Valley of north coastal Peru

Abstract

Objectives: In Lambert and Welker (2017) we explored the association between subsistence economy and postcranial fracture prevalence, finding that low-intensity agriculturalists exhibited significantly lower fracture rates than foragers or high-intensity agriculturalists. Here, we explore the impacts of sampling strategy on fracture rates in a sample of high-intensity agriculturalists from the Moche Valley, Peru, and further test the hypothesis that postcranial fracture risks are higher for intensive agriculture. Materials and methods: The long bones and clavicles of 102 individuals from an Early Intermediate Period cemetery (400 B.C.-A.D. 200) at Cerro Oreja were examined for healed fractures.Sample composition was manipulated in six ways to investigate the effects of age and element completeness on estimates of fracture prevalence. Fracture rates at Cerro Oreja were then compared to those for other high-intensity agriculturalists.Results: Both skeletal element completeness and age composition were found to influence fracture rate estimates, reflecting the greater likelihood of identifying healed fractures on betterpreserved bones and the accrual of injuries with age. The fracture rate of 3.4% at Cerro Oreja was the median value among seven high-intensity agriculturalist samples. The fracture distribution at Cerro Oreja was most similar to that observed at Kulubnarti, Sudan (Kilgore et al., 1997).Discussion: Skeletal element completeness and age composition can impact fracture rates estimated for skeletal samples and should be considered when conducting comparative analyses.All rates calculated for Cerro Oreja are within the range of those obtained for other highintensity agriculturalists and support previous findings that traumatic injury risk is higher for high-intensity agriculturalists. Similarities between Cerro Oreja and Kulubnarti suggest that rugged terrain may exacerbate fracture risk for agriculturalists, illustrating the costs of intensive agriculture in suboptimal environments. K E Y W O R D S agricultural intensification, bioarchaeology, injury risk, Peru, postcranial fractures

The hazards of the pastoralist lifestyle: Evidence from postcranial fractures in Middle Bronze and Early Iron Age populations of the Forest‐Steppe Altai, Russia

“…A global comparative analysis has shown that high‐intensity agriculturalists employing cultivation techniques designed to increase harvest, low‐intensity agriculturalists practicing only minimal landscape modification, and hunter‐foragers have predictable differences in traumatic injury risk regardless of geographic locality (Lambert & Welker, 2017, 2019). High‐intensity agriculturalists and hunter‐gatherers exhibit significantly higher rates of long bone fractures in contrast to low‐intensity agriculturalists (ibid).…”