INTER-SECTION Volume III - Page 31

| Detecting Social Change | Figure 1. On the left (1a) is a section of a normal vertebrae visible and on the right (1b) a vertebrae affected by osteopo- rosis. The difference can be seen in both the external (cortical) and internal (trabecular) bone. The cortical bone in the right vertebrae is thinner and void spaces emerge in the matrix of the trabecular bone. Due to the thinner outer layer and larger gaps in the internal structure is the bone less dense and therefore more prone to fractures (photographs by S.A. Inskip, 2017). factors and osteoporosis make it relevant to study this disease in past populations since its prevalence conditions in the past (Brickley et al. 2006, 136). During the Industrial Revolution in Britain there was a change in nutrition, lifestyle and living conditions. London’s population more than doubled in size during the eighteenth and nineteenth century, especially for the poorer population (Schwarz 1992, 126). The urban expansion of narrow streets and industrial growth resulted in smog formation and blocked sunlight (Bucholz and Ward 2012, 333; Henderson et al. 2013, 256). Sunlight provides vitamin D, which is an important substance in the protection against osteoporosis. However, less sunlight would have affected the whole population of London. These recorded changes in nutrition, lifestyle and living conditions during the Industrial Revolution are largely conducive to the presence of osteoporosis in a population. This leads to the expectation that a greater prevalence of osteoporosis would be expected in the post-Medieval period than in the preceding period. However, earlier research by Roberts and Cox (2003), using a crude prevalence rate (CPR) demonstrated a decrease in prevalence between the Medieval and post-Medieval period in Great Britain (2.62% Medieval and 1.20% post- method to examine a change, the authors admit that the percentage value for their post-Medieval sample is only based on two cemeteries in London. Roberts and Cox (2003) recognise their limitations and therefore the rate based on the two sites could be a bias. This raises the question whether or not the crude prevalence rates presented for the Medieval and post-Medieval period are representative for the whole period and the whole of Britain. This is especially important since recent archaeological studies on os FV&62FRT6&RFV &FW2vFFR&W6VFVB&W7VG2g&FR7GVG'&&W'G2B6Rr֖W2WB#SRF27GVGFW&Vf&R2F76W72F2G&VB'&W6V&6rVFR6FW2g&FBvW֖RvWFW"FW&R27&V6R"FV7&V6P&WfV6Rb7FV&62GW&rFRFR`GW7G&Ɨ6F'6&r7FV&62&FW0&WGvVVǗ6VBFfGV2g&VFWf6VWFW&W2B7BVFWf6VWFW&W2FFW&2BWFG0FRFFW6VBF2&W6V&62FW&fVBg&Цf&F&fFVB'FRW6WVbF&6VwFR7FVv6FW&2&VVǗ6VB'FR6VG&RbV&&6Vw4"B2&VVV&Ɨ6V@'w&2"FRvV6P7FVv6&W6V&6FF&6Rt$BW6pFFvVW&FVB'B4"2FPGfFvRFBBfw2FR6RWFG2@Ǘ627G&FVw&6VB6&62&WGvVVFFFW&fVBg&FffW&VB7FGWF2&RFW&V'W6VFVB#rDU"4T5Dd#