Arcadia University, Glenside, Pennsylvania.
Biomechanics and Movement Science, University of Delaware, Newark, Delaware.
J Orthop Res. 2021 Jan;39(1):147-153. doi: 10.1002/jor.24666. Epub 2020 Mar 23.
Quadriceps dysfunction persists after anterior cruciate ligament reconstruction (ACLR), yet the etiology remains elusive. Inhibitory and facilitatory intracortical networks (ie, intracortical excitability) may be involved in quadriceps dysfunction, yet the investigation of these networks early after ACLR is sparse. The purposes of this study were to examine (a) changes in intracortical excitability in athletes after ACLR compared to uninjured athletes during the course of postoperative rehabilitation, (b) the association between intracortical excitability and quadriceps strength in athletes after ACLR. Eighteen level I/II athletes after ACLR between the ages of 18 to 30 years and eighteen healthy sex, age, and activity matched athletes were tested at three-time points: (a) 2 weeks after surgery, (b) achievement of a "quiet knee" defined as full range of motion and minimal effusion, (c) return to running time point defined as achievement of a quadriceps index ≥80% and at least 12 weeks post-ACLR. Short-interval intracortical inhibition (SICI) and intracortical facilitation (ICF), measured via transcranial magnetic stimulation and isometric quadriceps strength were examined bilaterally at each time point. There was a significant group × limb interaction (P = .017) for ICF. The ACLR group demonstrated asymmetric ICF (greater in the nonsurgical limb) compared to controls and a significant relationship between SICI and quadriceps strength of the surgical limb at the quiet knee time point (P = .018). ACLR individuals demonstrate differential effects on ICF between limbs. Also, SICI is associated with isometric quadriceps strength after ACLR, suggesting increased inhibition of the motor cortex may contribute to impaired quadriceps strength following ACLR.
股四头肌功能障碍在 ACLR 后仍然存在，但病因仍不清楚。抑制性和易化性皮质内网络（即皮质内兴奋性）可能与股四头肌功能障碍有关，但在 ACLR 后早期对这些网络的研究很少。本研究的目的是检查：（a）与未受伤的运动员相比，ACL 重建后的运动员在术后康复过程中皮质内兴奋性的变化；（b）ACL 重建后运动员皮质内兴奋性与股四头肌力量的关系。18 名 ACLR 后 I/II 级运动员（年龄 18-30 岁）和 18 名健康、性别、年龄和活动匹配的运动员在三个时间点进行了测试：（a）手术后 2 周；（b）达到“安静的膝关节”定义为全范围运动和最小的积液；（c）重返跑步时间点定义为达到股四头肌指数≥80%，ACL 后至少 12 周。通过经颅磁刺激和等长股四头肌力量测量双侧短间隔皮质内抑制（SICI）和皮质内易化（ICF）。ICF 存在显著的组-肢交互作用（P=0.017）。ACL 组与对照组相比，表现出不对称的 ICF（非手术侧更大），并且在安静膝关节时间点，SICI 与手术侧股四头肌力量之间存在显著关系（P=0.018）。ACL 组的 ICF 双侧存在不同的影响。此外，SICI 与 ACLR 后等长股四头肌力量相关，提示运动皮层的抑制增加可能导致 ACLR 后股四头肌力量受损。
