The relationship between foot alignment and inter-segmental foot kinetics during running

Abstract

Differences in foot kinetics related to foot alignment have been suggested to be a contributing factor for running-related injuries. However, the influence of foot alignment on multi-segmental foot kinetics during running remains incompletely understood. The present study aimed to investigate the relationship between foot alignment and inter-segmental foot kinetics during running. Twelve males performed barefoot running with rearfoot strike at 3.3 m/s ± 10% along a 10 m runway. We simultaneously recorded multi-segmental foot kinematics, plantar pressure, and ground reaction force using a three-dimensional motion analysis system and a plantar pressure sensor. The ground reaction force was distributed to the rear- and forefoot based on the pressure ratio of each segment. Sagittal moment, power and work at the ankle and midfoot were calculated using an inverse dynamics approach. Foot alignment was assessed by Foot Posture Index (FPI). Spearman's rank correlation coefficient was used to examine the relationship between FPI and kinetic parameters at the ankle and midfoot (α = 0.05). FPI was significantly correlated with peak plantarflexion moment at the ankle and midfoot (ρ = 0.72, p < 0.01; ρ = 0.63, p = 0.03, respectively). FPI also showed a significant correlation with peak positive power (ρ = −0.70, p = 0.01) and positive/negative work at the ankle (ρ = −0.71, p < 0.01; p = 0.63, p = 0.03, respectively). These findings suggest that the assessment of foot alignment is useful for estimating the foot and ankle kinetics during running.