Comparative adaptations of lower limb biomechanics during unilateral and bilateral landings after different neuromuscular-based ACL injury prevention protocols

Abstract

Potentially valuable anterior cruciate ligament (ACL) injury prevention strategies are lengthy, limiting training success. Shorter protocols that achieve beneficial biomechanical adaptations may improve training effectiveness. This study examined whether core stability/balance and plyometric training can modify female landing biomechanics compared with the standard neuromuscular and no training models. Forty-three females had lower limb biomechanics analyzed during unilateral and bilateral landings immediately before and after a 6-week neuromuscular or no training programs. Sagittal and frontal plane hip and knee kinematics and kinetics were submitted to 3-way repeated-measures analyses of variance to test for the main and interaction effects of training group, landing type, and testing time. Greater peak knee flexion was evident in the standard neuromuscular group following training, during both bilateral (p = 0.027) and unilateral landings (p = 0.076 and d = 0.633). The plyometric group demonstrated reduced hip adduction (p = 0.010) and greater knee flexion (p = 0.065 and d = 0.564) during bilateral landings following training. The control group had significant reduction in peak stance knee abduction moment (p = 0.003) posttraining as compared with pretraining. The current outcomes suggest that significant biomechanical changes are possible by an isolated plyometric training component. The benefits, however, may not be evident across all landing types, seemingly limited to simplistic, bilateral landings. Integrated training protocols may still be the most effective training model, currently improving knee flexion posture during both bilateral and unilateral landings following training. Future prevention efforts should implement integrated training protocols that include plyometric exercises to reduce ACL injury risk of female athletes.