en آسیب شناسی ورزشی و حرکات اصلاحی Sport injury and corrective exercises پژوهشي Research <div style="text-align: justify;"><strong>Purpose</strong>: Anterior cruciate ligament (ACL) reconstruction is the standard treatment for restoring knee joint function, but patients undergoing this surgery show deficits in sensorimotor control that often impair movement coordination of the lower limb. This study aimed to investigate the coordination and coordination variability of lower limb joints during single-leg stance in individuals with ACL reconstruction.<br> <strong>Methods</strong>: The study analyzed 24 participants: 12 with right ACL reconstructions using hamstring autografts (12-16 months post-surgery) and 12 healthy controls, all of the same gender and aged 20&ndash;37. Kinematic variables of lower limb joints were recorded using eight motion analysis cameras (250 Hz). Inter-joint coordination and coordination variability were examined using the continuous relative phase (CRP) method across different phase planes involving angular velocity, acceleration, and jerk for the ankle, knee, and hip joints in the anterior-posterior direction.<br> <strong>Results</strong>: ACL-reconstructed individuals showed higher hip-ankle joint coordination in angular velocity (P=0.004), indicating a reduction in coordination between these joints and reduced coordination variability in hip-knee (all phase planes) and knee-ankle joints (velocity-acceleration and jerk-acceleration phase planes) compared to the healthy group (P<0.05).<br> <strong>Conclusion</strong>: Altered movement patterns in individuals with ACL reconstruction could increase the risk of reinjury. Thus, it is necessary to design optimal rehabilitation protocols for these patients.</div> Anterior cruciate ligament (ACL) reconstruction, Singleleg stance, Coordination, Coordination variability 433 444 http://ptj.uswr.ac.ir/browse.php?a_code=A-10-714-1&slc_lang=en&sid=1 Leila Ghazaleh L.ghazaleh@alzahra.ac.ir 0000-0002-5228-2703 No Department of Exercise Physiology, Faculty of Sport Sciences, Alzahra University, Tehran, Iran. Banafsheh Mohammadi b.mohammadi@sku.ac.ir 0000-0001-9951-2265 Yes Department of Sport Sciences, Faculty of Literature and Humanities, Shahrekord University, Shahrekord, Iran. Maede Alavikiaa maalavikia@yahoo.com 0000-0002-7971-3905 No Department of Biomedical Engineering Biomechanics, Amirkabir University of Technology, Tehran, Iran. Peyman Aghaie Ataabadi Peymanaghaiee@ut.ac.ir 0000-0003-0719-455X No Department of Sports Injury and Biomechanics, Faculty of Sport Sciences and Health, University of Tehran, Tehran, Iran. Seyyed Morteza Kazemi morteza@sbmu.ac.ir 0000-0003-3631-1305 No Bone, Joint And Related Tissues Research Center, Akhtar Hospital, Shahid Beheshti University Of Medical Sciences, Tehran, Iran. Nader Farahpour naderfarahpour1@gmail.com 0000-0002-5883-7845 No Department of Sport Biomechanics, Faculty of Sports Sciences, Bu-Ali Sina University, Hamedan, Iran.