Femoral angle development and locomotor progression in children from 18th and 19th century London

The external geometry of the human femur changes markedly during early ontogeny as children learn to sit, crawl, stand, and eventually walk. Here we examine the pattern of femoral angle development in a sample of children from 18th and 19th century London and evaluate how angular changes correspond to key stages of childhood locomotor development. Metaphyseal bicondylar angle (BCA) and neck-shaft angle (NSA) measurements were collected from radiographs of a documented archeological sample of 112 children aged from birth to 8.5 years. Ontogenetic patterns were assessed by using a local regression (LOESS) to fit curves to each angle parameter according to chronological age and femur length, and group comparisons were made between successive locomotor stages. The results demonstrate an increase in BCA throughout growth, which accelerates rapidly between the ages of 1 and 2 years when children first start to walk with an immature waddling gait. NSA was observed to increase during the first few months after birth, followed by a rapid decline at about 7 months and a steady decline during the second year when children learn to walk. The findings from this study contribute to the current literature on femoral angle development and provide an insight into femur development in children from industrial London. Further research is required to ascertain whether this pattern of NSA development is specific to the studied population.