Visual Memory Influences the Effect of Soccer Ball Handling on Knee Valgus Angle while Cutting

Abstract

BACKGROUND: Sports injuries remain a major concern for athletes despite ongoing efforts to improve screening and prevention methods. Recent research suggests that neurocognition may play a role in the neuromuscular control associated with injuries such as anterior cruciate ligament tears. Additionally, sport-specific tasks, such as dribbling a soccer ball, are integral to playing sports, but may also influence lower extremity mechanics. The relationship between neurocognitive ability and biomechanics during a sport specific cutting task has yet to be investigated. PURPOSE: To determine the relationship between neurocognition and the effect of soccer ball handling on lower extremity mechanics during a side-step task. METHODS: Fifteen healthy male collegiate soccer players (20.8 ± 2.0 yr; 1.77 ± 0.07 m; 77.0 ± 8.6 kg) participated in the study. Participants performed anticipated 45° run-to-cut trials while dribbling a soccer ball (BH) and without dribbling (NB) while 3D kinematics and kinetics were recorded. Approach speeds of NB trials were matched to those of BH trials. Peak knee valgus angle (pKValA) and moment for the plant leg were calculated. Participants also completed the ImPACT® neurocognitive assessment to evaluate visual and verbal memory, reaction time, and visual motor speed. Composite scores from the neurocognitive assessment were entered as candidate linear regression predictors for the change scores in lower extremity biomechanical parameters (i.e., BH – NB). Promising models with respect to adjusted-R2 and Mallow’s Cp were further evaluated for significance (α=0.05) through linear regression analysis. RESULTS: A one unit decrease in the visual memory composite score (i.e., worse visual attention, scanning, and/or visual learning) was associated with an increase in pKValA of 0.25° ± 0.07° during the BH task compared to the NB task (R2 = 45.8%, p = 0.006). CONCLUSION: The detrimental effect of soccer ball handling during a side-step cut movement on knee valgus was found to be influenced by athletes’ visual memory ability. These results may suggest that athletes with a diminished capacity for visual memory may be less able to maintain optimal biomechanics while accommodating the demands of sport-specific tasks that require visual attention.