The effects of knee ligament loading during running in different foot strike patterns

Abstract

Background The purpose of this study is to examine the kinematic and kinematic variables during running with various foot strike patterns and to calculate the knee ligament loading using musculoskeletal modeling techniques. Methods Twenty participants were instructed to run overground at 4.3 ± 0.2 m/s along the instrumented runway, with landing their feet on the force plate under three foot strike patterns: forefoot (foot strike angle < -1.6°), midfoot (-1.6° < foot strike angle < -8.0°), rearfoot (foot strike angle > 8.0°). The angle, angular velocity, ground reaction force (GRF), and moment of the knee joint were calculated, and anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) forces were determined through musculoskeletal modeling. Results The forefoot strike had a significant shorter contact time than the midfoot and rearfoot strike (p < .05). The forefoot strike was lower than other foot strike patterns for flexion angle (F = 7.261, p = .005). In the kinetic variables, the forefoot strike showed single vertical GRF peak that was higher than the first or second peaks in other foot strike patterns (p < .05). The anterior and posterior ACL loading of the rearfoot strike were lower than forefoot and midfoot strike patterns (p < .05), while no significant between strike patterns were found in PCL loading. Conclusion This suggests that the lower ACL load of the rearfoot strike would be associated with the two-peak GRF characteristics with the impact attenuation at initial contact, and that forefoot strike showed a relatively high ACL load due to the small foot contact area for both landing and propulsion.