Reducing anterior cruciate ligament injury risk factors by training perception: How vital is maintaining the perception-action coupling?

This study investigated the effect of maintaining perception-action coupling during a 4-week perceptual training program aiming to reduce biomechanical risk factors associated with ACL injury. Kinetic (valgus and internal rotation knee moments) and neuromuscular (total knee muscle activation and directed co-contraction ratios) variables were calculated during evasive sidestepping of 3D-projected opponents in 1-on-1, 2-on-2 and 3-on-3 game-based situations pre and post-intervention training. An additional transfer scenario was assessed post-intervention. Twenty-six amateur Australian Rules footballers were allocated to control (C), uncoupled (U) or coupled (PA) groups. Participants completed biweekly perceptual training containing 48 trials requiring a verbal (uncoupled) or running sidestep (coupled) response while counting the number of attentional cues displayed. Training groups showed no reductions in peak valgus and internal rotation moments, however, a small decrease in peak valgus moments was observed in the transfer condition. Coupled training displayed significant group differences in medial-lateral co-contraction ratios from controls. No changes in muscle activation patterns pre-post ARF were observed, however C and UC groups redirected co-contraction ratios laterally in the transfer condition. Results suggest that attentional cueing perceptual training with a coupled response may have a beneficial impact on kinetic ACL injury risk factors and maintain muscle activation levels associated with decreased ACL injury risk.