Effect of a Visual Dual-Task on Single-Leg Countermovement-Jump in Male Professional Soccer Players with Lower-Limb Injuries: A Cross-Sectional Observational Study.

Background

Participation in soccer imposes high physical, mechanical, and cognitive demands. Recent evidence suggests that cognitive load, often overlooked in injury prevention, interacts with biomechanical factors and injury risk, resembling a dual-task paradigm where players must adapt motor responses while processing unpredictable game situations. This cross-sectional observational study examined how adding a dual-task during single-leg countermovement-jumps (SLCMJ) affects neuromotor control and performance in elite soccer players.

Methods

Players performed SLCMJ on the injured leg while muscle activation, kinematics, and kinetics were measured, with and without a dual-task requiring color identification, via repeated-measures ANOVA; three injured groups (Chondropathy, n = 10, ACL, n = 15, Muscle Injury, n = 15) and a healthy control group (n = 22, followed the same protocol during final-rehabilitation stage.

Results

Specific main outcomes were kinetics, kinematics, and EMG variables. Kinetic performances were significantly higher (p < 0.001, d > 0.6) with dual-task: eccentric rate-of-force-development, jump-height, reactive-strength-index-modified, and shorter for time-to-peak of ground-reaction-force (p < 0.05, d > 0.6). Muscle activation increased with dual-task in rectus femoris and biceps femoris during pushing (eccentric and concentric phases) (p < 0.01, d = 0.7) and for medial gastrocnemius during landing (p < 0.05, d = 0.7). Kinematic analyses showed greater pushing knee flexion, while pushing and landing trunk flexion was lower (p < 0.01, d > 0.8). Kinetic values in the three injured groups were lower than those of controls (p < 0.01, d > 0.8).

Conclusions

Injured elite soccer players appeared disinhibited in dual-task conditions that improved SLCMJ performance but altered neuromotor control, underscoring the importance of a neurocognitive approach in return-to-play assessments to evaluate reinjury risk.