Purpose: The aims of this study were to evaluate the functional recovery before and after ACL reconstruction and to evaluate the sensitivity to change in performance-based and self-reported outcomes prior to and after ACL reconstruction and to determine whether these changes represent clinically relevant improvement.
Methods: Eighty-three athletes participated in this study. Athletes were tested after an ACL injury, after preoperative training, and 6 and 12 months after ACL reconstruction. Athletes completed quadriceps strength testing, hop testing, and self-reported questionnaires for knee function (International Knee Documentation Committee subjective knee form, Knee Outcome Survey-Activities of Daily Living Scale, and the Global Rating Scale of Perceived Function) at each testing period.
Results: A significant interaction of limb by time was seen in normalized quadriceps strength, and single, triple, and 6-m timed hop, where the involved limb improved more than the uninvolved limb over time. A main effect of time was noted for performance-based limb symmetry indexes and self-reported measures.
Conclusion: Limb-to-limb asymmetries are reduced, and normal limb symmetry is restored after perturbation training and aggressive quadriceps strengthening and returned to similar levels 6 months after reconstruction. Performance-based values on the involved limb and self-reported outcomes are sensitive to change over time, and these were clinically relevant improvements.