Isokinetic Knee Strength and Multidirectional Jump-Landing Asymmetry in Professional Football Players After Anterior Cruciate Ligament Reconstruction: An Exploratory Cross-Sectional Study

Background/Objectives: Isokinetic testing is widely used after anterior cruciate ligament reconstruction (ACLR), but isolated knee strength may not reflect function during braking, re-acceleration, and stabilization. This study examined relationships between isokinetic strength and vertical and multidirectional performance in professional football players after ACLR and compared asymmetry across functional domains.

Methods

Eleven male professional players, 12–40 months post-ACLR and back in unrestricted training and competition, completed isokinetic concentric knee extensor and flexor strength testing, single-leg countermovement and drop jumps, and unilateral and bilateral forward and lateral jumps on 3D force-plates. Limb differences, strength–performance associations, bilateral contributions, and domain-specific asymmetry were assessed.