Spondylolysis patterning in two native Alaskan skeletal collections

Scott S. Legge, Macalester College

Abstract

The frequency and patterning of spondylolytic separations are examined in skeletal collections from Golovin Bay and Nunivak Island, Alaska. Previous researchers have observed high frequencies of spondylolysis among skeletal collections from the Canadian Arctic and Greenland. It was expected that the collections from Golovin Bay and Nunivak would exhibit similar frequencies and patterns of lesions given a shared genetic background, based upon language, and similar subsistence resource utilization.

All vertebrae are observed and documented utilizing the Smithsonian protocol for skeletal analysis (Verano and Urcid, 1994). In the Golovin collection, when considering only those individuals with complete lumbar segments (N = 33), spondylolysis is observed in 18 individuals giving an overall frequency of 54.5%. When considered by individual vertebra, L5 exhibits the highest frequency among both males and females. However, among males the frequency of L5 spondylolysis is significantly higher than the frequency of L4 spondylolysis. Among females at Golovin there is no significant difference in the frequencies of L4 and L5 spondylolysis. The differential occurrence of spondylolysis between L4 and L5 may reflect different activities between males and females at Golovin Bay. In the Nunivak collection only one individual out of 20 with complete lumbar segments exhibits spondylolysis. Comparisons between males and females within the Nunivak collection are not possible because of the limited occurrence of this pathology. Ethnographic data from both regions suggest that these populations utilized similar subsistence resources, however spondylolysis frequencies and patterning supports the concept of subtle differences in the methods for gathering those resources. American Journal of Physical Anthropology, Volume 126, Supplement 40: 136 (Abstract)