Anterior Cruciate Ligament (ACL) injuries are among the most common and debilitating knee injuries, particularly in multidirectional sports. ACL reconstruction (ACLR) is a widely used surgical intervention, yet the pathway to optimal recovery remains a topic of debate. One of the key milestones in post-surgical rehabilitation is the return to running, an essential component in the recovery process.
Biomechanical studies reported that for every step taken during running, the weight acceptance of the athlete is estimated to be around, and sometimes over, 2–3 times the athlete’s body mass. Failure to match the task demands and the athlete’s load tolerance may result in significant load absorbed by passive structures (e.g., menisci, ligaments, joints, etc.), potentially leading to overload. Therefore, a shift from a time-based to a criteria-driven rehabilitation approach implemented to assess athlete readiness is vital to ensure a safe and effective return to running process.
The paper by Compagnin, Gastaldo, and Della Villa provides a structured, criteria-based approach to guide clinicians and athletes through this complex process. The authors emphasise the importance of understanding the biomechanical demands of running and aligning rehabilitation strategies with the athlete’s physiological and functional readiness. This includes achieving minimal pain (numeric rating scale ≤3), and swelling (activity-related effusion ≤1cm), restoring knee range of motion (full extension and ≥120°/130° of knee flexion), developing sufficient quadriceps and hamstring strength (isokinetic test ≥70% Limb Symmetry Index), and ensuring proper neuromuscular control (optimal foundational task kinetics and kinematics). Additionally, progressive loading strategies, gait retraining, and individualised rehabilitation plans are crucial for optimising outcomes and reducing re-injury risk.
This evidence-based framework, that encompasses five key domains (joint homeostasis, knee mobility, gait biomechanics, strength, and functional movement) that should be assessed and addressed before running retraining, bridges the gap between research and clinical practice, providing professionals with a practical guide to help athletes return to running safely and efficiently after ACL reconstruction.
