en بیومکانیک ورزشی Sports biomechanics پژوهشي Research <div style="text-align: justify;"><span style="font-size:14px;"><span style="font-family:Tahoma;"><span style="line-height:2;"><b><span lang="EN">Purpose:</span></b><span lang="EN"> Persistent neuromuscular deficits following anterior cruciate ligament reconstruction (ACLR) have been linked to alterations in central neural drive and disrupted cortico-muscular communication. This study investigated cortico-muscular interactions and neuromuscular control during a steady force task in athletes following ACLR compared with healthy athletes.</span><br> <b><span lang="EN">Methods:</span></b><span lang="EN"> Twenty-four male athletes participated in this cross-sectional study, including 12 athletes who had undergone unilateral ACL reconstruction using a hamstring tendon autograft and 12 uninjured healthy athletes. Athletes in the ACLR group were tested 10.0 &plusmn; 2.0 months post-surgery. Participants performed a standardized steady isometric force task. Cortical activity was recorded using electroencephalography, and surface electromyography was recorded from the semitendinosus muscle. Cortico-muscular coherence (CMC) was calculated in the beta (13&ndash;30 Hz) and gamma (30&ndash;60 Hz) frequency bands. Force steadiness was quantified using the coefficient of variation of force (ForceCV), and inter-limb asymmetry was assessed using a functional asymmetry ratio.</span><br> <b><span lang="EN">Results:</span></b><span lang="EN"> The ACLR and Healthy groups did not differ in age, height, body mass, or BMI (p > 0.05). Force steadiness was significantly reduced in the ACLR group, with higher ForceCV values than in healthy athletes (4.5 &plusmn; 0.7% vs. 3.0 &plusmn; 0.7%, p < 0.001, d </span><span dir="RTL" lang="AR-SA">=</span><span lang="EN"> 2.14). Cortico-muscular coherence analysis revealed limb-specific alterations in the ACLR group, particularly in the beta band, where coherence tended to be lower in the reconstructed limb compared with the contralateral limb. Healthy athletes demonstrated near-symmetrical coherence between dominant and non-dominant limbs. A similar but smaller pattern was observed in the gamma band. Inter-limb functional asymmetry was significantly greater in the ACLR group (1.30 &plusmn; 0.11) than in the Healthy group (1.00 &plusmn; 0.11; p < 0.001, d = 2.73). ForceCV was strongly correlated with the functional asymmetry ratio across all participants (r = 0.99, p < 0.001).</span><br> <b><span lang="EN">Conclusion:</span></b><span lang="EN"> Athletes following ACL reconstruction exhibit altered cortico-muscular interactions, reduced force steadiness, and greater inter-limb asymmetry during a controlled force task. These findings indicate that persistent neuromuscular deficits after ACLR may involve disrupted neural-muscular coupling between the central nervous system and peripheral musculature. Rehabilitation strategies targeting both neuromuscular control and central neural mechanisms may therefore be important for restoring symmetrical motor function after ACL reconstruction.</span></span></span></span></div> Anterior Cruciate Ligament Reconstruction, Electroencephalography, Electromyography, Motor Control, Sensory Motor Cortex 0 0 http://ptj.uswr.ac.ir/browse.php?a_code=A-10-543-1&slc_lang=en&sid=1 Sajjad Abdollahi abdollahi.sjd@gmail.com 0000-0002-7144-9249 Yes Department of Sport Biomechanics, Faculty of Sports Sciences, Bu-Ali Sina University, Hamedan, Iran. Mehrdad Anbarian anbarian@basu.ac.ir 0000-0002-3605-5586 No Department of Sport Biomechanics, Faculty of Sports Sciences, Bu-Ali Sina University, Hamedan, Iran. Rahman Sheikhhoseini rahman.pt82@gmail.com 0000-0002-9885-3591 No Department of Corrective Exercise and Sport Injury, Faculty of Physical Education and Sport Sciences, Allameh Tabataba’i University, Tehran, Iran.