Limb Length Discrepancy: Prevalence, Patterns, and Variation in Pre- and Post-Industrial Humans

Abstract

Limb length discrepancy is a condition in which bilateral limb length is unequal. Leg length discrepancy is surprisingly common and, depending on its magnitude as well as the individual’s activity level, it can contribute and/or cause various physical issues. Arm length discrepancy, on the other hand, is believed to cause little to no physical issues albeit being relatively poorly explored and understood. In specific cases of leg length discrepancy, the cause is usually not known. This study uses the long bone lengths of pre- and post-industrial human skeletons to calculate the arm and leg length discrepancies in the pre- and post-industrial populations. Moreover, this paper calculates the prevalence, average magnitudes, and directional biases of the respective limb length discrepancies and evaluates how they differ between groups based on contemporaneity, sex, race, age, birth year, handedness, height, and weight. This thesis finds that there are many demographic correlations with arm and leg length discrepancy, which suggests that the acquired causes of limb length discrepancy are more diverse and complex than previously thought.