Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
Department of Medical Biostatistics, University of Vermont, Burlington, VT, USA.
Clin Biomech (Bristol). 2021 Jan;81:105231. doi: 10.1016/j.clinbiomech.2020.105231. Epub 2020 Nov 17.
The permanence of neuromuscular adaptations following anterior cruciate ligament reconstruction is not known. The aim of this study was to compare bilateral muscle co-contraction indices, time to peak ground reaction force, and timing of muscle onset between anterior cruciate ligament reconstruction subjects 10-15 years post reconstruction with those of matched uninjured controls during a one-leg hop landing.
Nine healthy controls and 9 reconstruction subjects were recruited. Clinical and functional knee exams were administered. Lower limb co-contraction indices, time to peak ground reaction force, and muscle onset times were measured bilaterally. Differences in clinical and functional outcomes were assessed with unpaired t-tests, and mixed model repeated measures were used to examine effects of group, limb and interaction terms in electromyography measures.
89% of control knees were clinically "normal", whereas only 33% of reconstructed knees were "normal". Anterior cruciate ligament-reconstructed subjects tended to achieve shorter functional hop distances but demonstrated symmetrical lower limb electromyography measures that were no different from those of controls' with the exception that biceps femoris activation was delayed bilaterally prior to ground contact but was greater during the injury risk phase of landing.
With the exception of hamstring activation, lower limb electromyography measures were largely similar between ligament-reconstructed and matched control subjects, which was in contrast to the clinical findings. This result brings into question the significance of neuromuscular function at this long-term follow-up but raises new questions regarding the role of symmetry and pre-injury risk.
前交叉韧带重建后神经肌肉适应性的持久性尚不清楚。本研究的目的是比较前交叉韧带重建后 10-15 年的双侧肌肉协同收缩指数、峰值地面反力时间和肌肉起始时间，与匹配的未受伤对照组在单腿跳跃着陆时的情况。
招募了 9 名健康对照组和 9 名重建组受试者。进行了临床和功能膝关节检查。测量了双侧下肢协同收缩指数、峰值地面反力时间和肌肉起始时间。使用独立样本 t 检验评估临床和功能结果的差异，并使用混合模型重复测量来检验肌电图测量中组、肢体和相互作用项的影响。
89%的对照组膝关节临床“正常”，而只有 33%的重建组膝关节“正常”。前交叉韧带重建组受试者倾向于实现较短的功能性跳跃距离，但表现出对称的下肢肌电图测量值，除了双侧股二头肌在触地前延迟激活，但在着陆的受伤风险阶段更大，与对照组的测量值没有不同。
除了腘绳肌激活外，重建组和匹配对照组的下肢肌电图测量值在很大程度上相似，这与临床发现形成对比。这一结果对长期随访时神经肌肉功能的重要性提出了质疑，但对对称性和受伤前风险的作用提出了新的问题。
