ACL重建后中枢运动控制改变：高风险落地时的肌肉协同分析
简介
22例单侧ACL重建患者与16例健康对照完成单腿落地侧跳任务，采用表面肌电（14块肌肉）结合非负矩阵分解提取肌肉协同模式。ACLR患侧落地时股四头肌权重过度、额状面稳定协同模块（臀中肌/腓骨长肌）缺失、协同募集时序紊乱，且与不良膝关节生物力学相关。提示针对特定肌肉协同异常的神经肌肉训练或有助于降低二次损伤风险、安全重返运动。
英文摘要
PURPOSE: Anterior cruciate ligament reconstruction (ACLR) patients face elevated secondary injury risk due to residual neuromuscular deficits, yet the neuromuscular coordination strategies underlying altered muscle coordination remain unclear. Muscle synergy (MS) analysis offers a valuable framework for elucidating these mechanisms. This study characterized MS patterns in ACLR patients during high-risk landing and their correlation with lower-extremity biomechanics. METHODS: Twenty-two patients who had undergone unilateral ACLR performed a single-leg drop-land-lateral jump task using both affected and nonaffected limbs, whereas sixteen healthy controls performed the task using their dominant limb. with the limb-level data were subsequently categorized into three groups: affected, nonaffected, and control. Surface electromyography (14 muscles), kinematics, and ground reaction forces were recorded. Non-negative matrix factorization was used to extract MS spatial (muscle weighting vectors) and temporal (activation profiles) components across pre-landing, impact, and loading phases. Joint angles/moments were computed via OpenSim musculoskeletal models. Mixed-effects models and Pearson correlations assessed group differences and synergy-biomechanics associations. RESULTS: Compared to controls, ACLR limbs showed lower hip abduction and ankle plantarflexion angle but greater knee flexion angle at landing, accompanied by excessive pre-landing quadriceps weighting, reduced gluteal/semimembranosus contributions, and earlier but lower-amplitude synergy recruitment. Post-landing, quadriceps weighting decreased and knee-dominant synergy recruitment delayed, with compensatory redistribution toward gluteal, gastrocnemius, and tibialis anterior muscles, corresponding to reduced knee extension and increased hip extension moments. Critically, during impact, ACLR limbs lacked a dedicated frontal-plane stabilization synergy, MS4 (gluteus medius/peroneus longus), relative to the control group. A greater number of synergies in the affected limb was associated with more normative joint biomechanics. CONCLUSIONS: ACLR limbs exhibit persistent, limb-specific MS abnormalities across all landing phases, including altered sagittal-plane quadriceps weighting, impaired frontal-plane modular control, and dysregulated synergy timing. These central neuromuscular coordination alterations correlate with maladaptive knee biomechanics, potentially increasing secondary ACL injury risk. From a sports training perspective, targeting these specific synergy alterations, particularly the missing frontal-plane stabilization module, may inform more effective neuromuscular training protocols for safe return to sport.