Long bone bilateral asymmetry in the nineteenth-century Stirrup Court Cemetery collection from London, Ontario

Abstract

This study employs non-destructive methods to investigate patterns of long bone bilateral asymmetry in a skeletal sample from the nineteenth-century peri-urban Stirrup Court Cemetery collection from London, Ontario, Canada. The St. Thomas Cemetery skeletal sample from urban Belleville, Ontario provides additional data for comparison. While one objective of the study is to determine the etiologies of any asymmetries and to identify patterns in what measurements on which bones displayed the most asymmetry, another objective is to test the hypothesis that limbs indicating asymmetry due to pathology or trauma in one element would show bilateral asymmetries elsewhere in the same bone and limb, due to either atrophy alone or to additional compensatory hypertrophy. Overall, the Stirrup Court data shows a general pattern of crossed symmetry, and when compared with the Belleville data the pattern of high and low absolute asymmetries is consistent. The results reveal a lack of asymmetry in elements with obvious long-term damage, which may indicate that caution is required in making determinations about lived impairment/disability in such cases. The sexual dimorphism in asymmetry in both samples, with males displaying more asymmetry in humeral minimum shaft circumference in the Stirrup Court sample, likely reflects the division of labor and behavior patterns in these populations. Finally, this study suggests that the effects of osteoarthritis may mask non-age-related impairment/disability, and that the skeletal record of impairment/disability is likely affected by differential preservation, with consequences for the emerging field of the archeology of disability.