Secular Trends in Human Skeletal Growth: Stature Change and Appositional Bone Development in a 19th and Early 20th Century Finnish Skeletal Population

Abstract

This thesis aims to examine secular changes in four skeletal growth parameters (recorded living stature, bone length, total cross-sectional area (TA) and twice average bending rigidity ‘J’ in femur, tibia and humerus) using adult male individuals from a 19th and early 20th century Finnish skeletal collection. Further objectives are to investigate whether the study individuals’ prisoner status introduces variation in the skeletal parameters within the sample as well as to examine what environmental indicators may have a relationship with the examined parameters. Data on bone cross-sectional geometric properties (CSG) were collected using a desktop 3D laser scanner whilst environmental data were acquired using existing Finnish data sources. The results showed a significant secular increase in stature, which was also reflected in femur length. Humeral (CSG) properties showed a significant secular decrease. Individuals who were prisoners had significantly smaller TA and lesser J at 35% length of the humerus than non-prisoners. It is concluded that the changing living conditions of late 19th and early 20th century Finland seem to have affected both endochondral and appositional bone growth of this sample, whereby improvements in the country’s disease and nutritional environment after the Finnish Famine could explain the found secular trend in stature and femur length. Changes in childhood loading history after the introduction of free elementary school in Finland are a possible explanation for the secular decrease in the humerus cross- sectional geometric properties, and might also be related to the found difference between prisoners and non-prisoners.