Effect of foot strike patterns and cutting angles on knee kinematics and kinetics during side-cutting maneuvers

Purpose Cutting maneuvers are important actions in multidirectional sports but associated with noncontact anterior cruciate ligament (ACL) injuries. This study aimed to investigate the effect of different foot strike patterns and cutting angles on knee kinematics and kinetics. Methods Twenty healthy male team sports athletes performed cuts with maximum speed at three angles (45°, 90°, and 135°) with different foot strike patterns (rearfoot strike [RFS] and forefoot strike [FFS]). A three-dimensional motion capture system combined with a force plate was used to collect makers trajectory and ground reaction force (GRF). Vertical GRF, and knee joint angles and moments were compared among these cutting tasks. Results Regardless of foot strike patterns, increased knee flexion angle, knee valgus moment, and knee internal rotation moment were observed during cutting to sharper angles (p < 0.001). At 90° and 135°, the FFS condition remained in a varus position and showed lower knee flexion moment than the RFS condition (p ≤ 0.004). However, no significant differences in knee kinematic and kinetic variables were found between foot strike patterns during cutting to 45°. Conclusions These findings suggest that sharper cutting angles potentially increase the risk of ACL injury. Compared with the RFS pattern, the FFS pattern induces a slight knee varus angle and a lower knee flexion moment at sharper angles, which might further reduce the load placed on the knee.