The Effect of Cross-education Training on Rehabilitation Outcomes in Patients with a History of Anterior Cruciate Ligament Reconstruction: A Systematic Review

Introduction: Anterior Cruciate Ligament Reconstruction (ACLR) often leads to Arthrogenic Muscle Inhibition (AMI) and impaired neural drive, posing significant challenges to rehabilitation. Cross education (CE) exercise, leveraging neuroplasticity, offers a potential strategy to manage these deficits. This systematic review synthesized evidence on the effects of CE interventions on rehabilitation outcomes, electromyographic indices, and biomechanical control post-ACLR. Methods: A structured search was conducted across PubMed, Scopus, Google Scholar, and national databases up to May 2026. Of 4,521 identified records, 12 randomized clinical trials (PEDro scores: 5–9) were included. Data were synthesized across three domains: muscular strength, neural adaptations, and functional outcomes. Results: High-intensity interventions, specifically those incorporating eccentric contractions three times per week and initiated from the second postoperative week, significantly attenuated quadriceps strength loss compared to control groups. Neuromuscular and biomechanical analyses demonstrated an increase in EMG activity and enhanced dynamic stability, characterized by a reduction in center of pressure (COP) excursions. While CE alone effectively improved muscle thickness, the concurrent application of blood flow restriction (BFR) did not yield significant incremental benefits. Discrepancies observed in certain functional outcomes were attributed to the inherent heterogeneity in the intensity and timing of the implemented interventions. Conclusion: Cross education is an efficient, neuroplasticity-based adjunct that bypasses physical constraints to preserve neural drive during early and intermediate recovery phases. While highly effective for restoring baseline strength and postural control, optimal return to sport outcomes requires integrating CE with plyometric and functional exercises in late-phase rehabilitation. Standardizing CE protocols remains imperative.