Neuromuscular Control Deficits After Anterior Cruciate Ligament Reconstruction: A Pilot Study Using Single-Leg Functional Tests and Electromyography

<b>Purpose:</b> This study aimed to evaluate neuromuscular control and muscle activation patterns in individuals following anterior cruciate ligament (ACL) reconstruction, compared to healthy controls. <b>Methods</b>: A cross-sectional comparative study was conducted following STROBE guidelines, including 16 participants (ACL group: n = 9; control group: n = 7). Participants performed the single-leg squat (SLS) test and the single-leg drop landing (SLDL) test. Neuromuscular control was assessed using the Qualitative Analysis of Single-Leg Loading Score (QASLS), while gluteus medius and vastus medialis activation were recorded using surface electromyography. <b>Results</b>: The ACL group showed significantly higher QASLSs in the SLS test (<i>p</i> = 0.0113), indicating poorer movement quality, while no difference was found in the SLDL test (<i>p</i> = 0.5484). Gluteus medius activation was lower in the ACL group during the SLS test (<i>p</i> = 0.0564), and vastus medialis activation was higher but not significantly different (<i>p</i> = 0.095). <b>Conclusions:</b> These findings highlight persistent neuromuscular deficits post-ACL-reconstruction, particularly in SLS tasks, reinforcing the need for targeted rehabilitation strategies focusing on hip stabilization and quadriceps motor control to optimize movement quality and reduce reinjury risk.