Sex differences in activity-related osseous change in the spine and the gendered division of labor at Ensay and Wharram Percy, UK

Abstract

Sex differences in the distribution of vertebral degenerative and plastic change were examined and compared within and between samples of 51 individuals from the historically and ethnographically documented 16th-19th century site of Ensay, the Outer Hebrides, and 59 individuals from the medieval site of Wharram Percy, the Yorkshire Wolds. Both populations have a known gendered division of labor between males and females and known activity-related stresses on the spine. Osseous changes normally associated with degenerative joint disease (osteoarthritis) of the apophyseal facets and osteophytosis of the vertebral bodies were scored and reported separately. Inter- and intrasite differences were found in the frequency and distribution of osseous change down the spine. Overall, the Ensay sample was more highly stressed than that from Wharram Percy. Furthermore, differences between males and females at Ensay could be identified as relating to different types of activities. Distinctions between males and females at Wharram Percy were less marked, suggesting broadly similar lifestyles. These results accorded with expectations regarding contrasting levels of activity-related stress at the two sites and the division of labor between males and females. In particular, the prevalence and distribution of facet remodeling, facet sclerosis/eburnation, and osteophytosis in Ensay females could be related to load-bearing using creels (a form of basket), which disrupted "normal" patterns of osseous change along the spine. Importantly, morphologically distinct osseous modifications recorded on the apophyseal facets produced dissimilar distributions, suggesting that they may have different etiologies. These results highlight the need for a high degree of discrimination in recording, analyzing, and exploring activity-related osseous change.

Using dental and activity indicators in order to explore possible sex differences in an adult rural medieval population from Thebes (Greece)

“…Age, weight and mechanical loading have been considered some of the most important etiological factors of OA (eg. Waldron 1997;Sofaer-Derevenski 2000;Solano 2002;Weiss 2005;. It is believed that severe OA scores on specific joints are the result of continued use of specific muscles and joints in daily and repetitive tasks (Weiss and Jurmain 2007).…”

“…Hence, is somewhat surprising, that plastic change (bone remodeling, and specifically spinal zygapophyseal facet remodeling) has been subject to less intensive study than OA. According to Sofaer-Derevenski (2000), the biomechanical forces leading to facet remodeling could make it one of the most reliable indicators of activity, and specifically of load bearing. Therefore, studying the distribution of facet remodeling along the spine could provide specific information as to how the loads might have been carried (ex.…”

“…Schmorl's nodes were also recorded as present or absent. Facet remodeling along the spine was recorded according to a four-stage system, formed by Sofaer-Derevenski (2000). According to this system, observations were made on the superior and inferior articular facets and changes such as the morphology of the margins were assessed giving the scores 0 to 3 for severity.…”

“…Load-carrying by tumpline, or on the head, have been associated with a peak in OA in the upper thoracic, the middle and lower thoracic, as well as the mid-cervical and lower lumbar vertebrae (Shore 1935;Steward 1979;Kilgore 1984;Jurmain 1990;Bridges 1994;Lovell 1994). However, a peak in OA specifically in the T1 (1 st ) thoracic vertebra has been associated with the method of carrying creels (Merbs 1983;Miles 1989;Sofaer-Derevenski 2000). There is no documented source informing us that carrying creels was a method of burden-carrying in medieval Thebes, therefore we cannot attribute the noted peak in T1 in males, to this specific method.…”

“…Activity patterns in the past were also related to social status. Sex-based division of labor in past populations has been documented in several studies (e.g., Merbs 1983;Sofaer-Derevenski 2000;Manzon and Gualdi-Russo 2016). A person's sex in the past was associated with their social status, although the factor of physical strength should not be ignored.…”