Multiplanar Force-Plate Assessment of Direction-Specific Interlimb Asymmetry in Professional Football Players After ACL Reconstruction

Inter-limb differences may be observed after anterior cruciate ligament reconstruction (ACLR), even after return to professional sport. This study examined whether anterior–posterior (AP) and medial–lateral (ML) ground reaction force impulses provide information complementary to vertical metrics during bilateral and unilateral jump-landing tasks in professional football players after ACLR, and whether inter-limb asymmetry profiles vary according to task type and movement phase. Twelve male professional football players assessed 12–40 months after primary ACL reconstruction were initially enrolled. One player was excluded before analysis because of insufficient signal quality, leaving 11 players in the final analytical sample. They completed bilateral and unilateral countermovement jumps, drop jumps, and a multi-rebound jump on three-dimensional force platforms. Vertical (V), AP, and ML impulses were analyzed during braking and propulsion together with jump height, reactive strength index, contact time, power, and stiffness. No operated-versus-non-operated difference remained significant after correction for multiple comparisons. Under the prespecified exploratory criteria, cross-direction discordance was observed in 73% of players and occurred more frequently during unilateral than bilateral assessments. AP or ML was the direction of greatest asymmetry in 89% of pooled athlete–task–phase observations; these repeated observations were interpreted descriptively. Vertical asymmetry was not consistently associated with AP or ML asymmetry, and comparable jump performance could coexist with directional force differences. Unilateral tasks and multiplanar analysis therefore provided complementary information, but the clinical relevance of these findings requires validation in larger controlled studies.