Females are more likely to sustain lower extremity injuries than males. Many injury risk functions (IRFs) for females are derived from scaled male data. Biomechanical differences between males and females in the lower extremity are known, but little is known about how these differences affect the applicability of scaling between the sexes. Twenty matched pair small female PMHS legs were tested by applying inversion and eversion of the ankle, matching a condition previously tested on males and larger females. For the new dataset, half the specimens were barefoot and the remainder were shod. The goal of this study was to generate IRFs for ankle inversion and eversion from a combined dataset of male and female PMHS tests to determine the extent to which sex, scaling, and the presence of a shoe affect the prediction of ankle injury tolerance. Results suggest that sex-specific IRFs exhibit greater predictive ability than those developed with scaled male and female data combined. Scaling inversion and eversion moment was found to misconstrue the measured data, even within the same sex. Therefore, IRFs for each sex (no specific anthropometry) are recommended. Absence or presence of a shoe was a significant predictor of injury tolerance and the presented IRFs take both conditions into account.