Biomechanical Evaluation of Deceleration in Patients Post-Anterior Cruciate Ligament Reconstruction via Force Plate: A Systematic Review

Objective To systematically review the biomechanical evidence regarding deceleration deficits in patients following anterior cruciate ligament reconstruction (ACLr) using force plate evaluation, and to identify the kinetic variables most sensitive to these functional impairments. Methods A systematic search was conducted across MEDLINE/PubMed, EMBASE, Scopus, Web of Science, and SPORTDiscus. Studies were included if they utilized force plates to evaluate kinetic variables during deceleration tasks (e.g., landing, change of direction, stop-jumps) in ACLR populations compared to healthy controls or the contralateral limb. Methodological quality was assessed using the Cochrane Risk of Bias tool and Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria Results Ten studies met the inclusion criteria. The evidence consistently demonstrates that ACLR patients exhibit a "protective behavior" during deceleration, characterized by a significant reduction in force absorption. Specific findings include a mean difference of 0.033 BWs in peak braking ground reaction forces compared to healthy controls. Deficits in eccentric deceleration impulse and peak force were found to persist between 6 and 9 months post-surgery, regardless of improvements in isolated quadriceps strength. Furthermore, ACLr limbs exhibited higher vertical loading rates (vGRF-LR) and significantly longer Time-to-Stabilization compared to peers. Notably, individuals achieving > 90% quadriceps strength symmetry still demonstrated persistent kinetic asymmetries during dynamic landing tasks. Conclusion Force plate analysis reveals critical kinetic deficits in braking impulse and loading rates that traditional strength metrics fail to capture. Currently, no "pure" test for deceleration exists; instead, it is evaluated as a phase within complex tasks, leading to high methodological variability. Standardizing force plate protocols for deceleration is essential for refining return-to-sport criteria and mitigating long-term risks of joint degeneration.