Effects of varying amounts of pronation on the mediolateral ground reaction forces during barefoot versus shod running.

Despite extensive research on running mechanics, there is still a knowledge gap with respect to the degree of relationship between mediolateral ground reaction forces (ML-GRF) and foot pronation. Our goal was to investigate whether differences exist in ML-GRF among runners that exhibit different degrees of pronation. Seventeen male and 13 female recreational runners ran with and without shoes while ML-GRF and frontal kinematics were collected simultaneously. Subjects were divided into groups based upon their peak eversion (low pronation, middle pronation, high pronation). Discrete parameters from the ML-GRF were peak forces, respective times of occurrence, and impulses. No significant differences were found between groups regarding the magnitude of ML-GRF. Based upon the relative times of occurrence, the peak medial GRF occurred closer to the peak eversion than the peak lateral GRF. Findings support the idea that the ML-GRF have less to do with pronation than previous research suggested.