📄 Abstract
BACKGROUND Anterior Cruciate Ligament (ACL) injury precipitates not only peripheral structural damage but also central neuroplastic reorganisation. Disrupted afferent input alters sensorimotor integration, reduces corticospinal excitability, and destabilises motor engrams governing quadriceps activation and dynamic knee control. These cortical adaptations manifest as persistent arthrogenic inhibition and functional asymmetry despite successful reconstruction. Therefore, effective rehabilitation must integrate neural restoration with tissue healing to achieve true limb symmetry and safe return to sport. Recent research shows that ACL rupture disrupts motor engrams—the brain’s stored movement patterns responsible for quadriceps activation, proprioception, and dynamic knee stability. These cortical changes contribute to quadriceps inhibition, altered gait, and delayed functional recovery even after successful reconstruction. Therefore, ACL rehabilitation must target both tissue healing and the restoration of disrupted neural pathways. AIM: To explore how motor engram disruption and cortical reorganisation influences recovery after ACL injury and to propose a neuro-integrative rehabilitation as an evidence-supported neuroplasticity technique that can facilitate brain-based rehabilitation and functional symmetry and safe return to sport. OBJECTIVES: Primary Objective: To conceptually analyse the role of motor engram disruption, cortical reorganisation and central neuroplastic changes following ACL injury, and to establish a brain-based framework for rehabilitation. Secondary Objectives: To explain the concept of motor engrams and cortical reorganisation role in normal knee motor control and dynamic stability. 1. To synthesise existing evidence on the relationship between altered sensory input, cortical reorganisation, and quadriceps inhibition after ACL injury. 2. To conceptually propose Motor Imagery and cortical reorganisation as an adjunct neuroplasticity-based intervention in ACL rehabilitation for return to sport symmetry. METHODOLOGY: This conceptual review synthesises current literature related to neuroplastic changes following ACL injury, motor learning mechanisms, corticospinal excitability changes and the role of Motor Imagery in neuromuscular re-education. Articles describing cortical reorganisation, reduced corticospinal excitability, symmetry deficits and MI-induced neural activation were analysed to develop a theoretical framework for brain-integrated ACL rehabilitation for return to sport symmetry. RESULTS: Studies report that ACL injury leads to decreased corticospinal excitability, altered motor cortex activation, and impaired sensorimotor integration. Motor Imagery has been shown to activate similar cortical regions as actual movement, supporting the reactivation of motor engrams. Evidence indicates that Motor Imagery and corticospinal excitability enhances quadriceps muscle activation, improves proprioceptive awareness, and strengthens brain–muscle pathways—especially valuable during early postoperative phases when physical loading is limited and during sports symmetry. CONCLUSION: ACL rehabilitation should progress beyond a purely structural approach and incorporate strategies that promote brain healing. ACL Rehabilitation should be evolved from biomechanical model to neuro-biomechanical paradigm that integrates tissue repair and cortical restoration. Motor Imagery is a safe, accessible, and evidence-supported neuroplastic technique that can restore disrupted motor engrams and improve long-term functional outcomes. A brain integrated rehabilitation approach may optimise return to sports outcomes. LIMITATIONS: Heterogeneity of included literature, Limited ACL-specific Motor Imagery and Cortical Reorganisation trials, Potential publication bias, Lack of standardized Motor Imagery protocols for return to sport symmetry, Indirect evidence from related knee conditions.
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📚 How to Cite:
Madhumitha Varadarajan, Dr.Sivakumar.S, Dr.Prakash Jayabalan, R.Edward Thainess Durai, R.Divya , REWIRING THE INJURED KNEE: CORTICAL REORGANISATION, MOTOR ENGRAMS, AND THE NEUROBIOLOGY OF RETURN-TO-SPORT SYMMETRY AFTER ACL INJURY- A CONCEPTUAL REVIEW , Volume 12 , Issue 6, June 2026, EPRA International Journal of Multidisciplinary Research (IJMR) , Pages: 815 - 819 , DOI: https://doi.org/10.36713/epra30725