Frontal Rearfoot Kinematics in Running Prior to Volitional Exhaustion

Abstract

Excessive rearfoot motion, especially in the frontal plane, is believed to be a major cause of overload injuries in running. The aim of this study was to determine the influence of fatigue on frontal rearfoot motion just before volitional abandonment during an exhaustive run on a treadmill. Rearfoot kinematics were recorded three-dimensionally and reconstructed in a frontal plane associated with the heel. Statistical analysis of the results suggested that exhaustion did not influence tibial varum substantially, except at first heel strike. However, maximal calcaneal eversion and subtalar pronation did increase significantly, while maximal pronation velocity accelerated to 100°/s more than at the start of the exhaustive run. Also, the results of this study suggest that the increase in rearfoot motion is directly affected by fatigue and not by a fatigue-induced increase in step length.