Lepley Adam S, Bahhur Nael O, Murray Amanda M, Pietrosimone Brian G
Musculoskeletal Health and Movement Science Laboratory, Department of Kinesiology, University of Toledo, 2801 W. Bancroft Street, Toledo, OH, 43606-3390, USA,
Knee Surg Sports Traumatol Arthrosc. 2015 Apr;23(4):1010-7. doi: 10.1007/s00167-013-2816-1. Epub 2013 Dec 11.
Deficits in quadriceps strength and voluntary activation are common following knee injury. These deficits are hypothesized to generate from a neural level, however, it remains unclear how corticomotor pathways are affected following acute injury. The purpose of this investigation was to examine whether corticomotor alterations of the quadriceps were present following a simulated knee joint injury using an experimental effusion model.
Participants completed two testing sessions, an experimental knee effusion and control session, separated by 7 days. The central activation ratio was used to assess change in quadriceps activation. Corticomotor excitability was assessed pre- and post-intervention via active motor thresholds (AMTs) and motor evoked potentials (MEPs) normalized to maximal muscle responses. MEPs were assessed at different percentages of AMT, and associated slopes between these percentages were analysed. Paired-sample t tests were performed on percentage change scores calculated from pre-intervention outcome measures to assess change in corticomotor excitability and changes in the slope of MEP values as percentage of AMT increased.
Quadriceps activation significantly decreased during the effusion session. AMT and MEP change scores were not different between effusion and control conditions. No substantial differences were found in slope between any percentages of AMT.
An experimental knee effusion did not induce changes in corticomotor excitability. Further research is needed to understand how corticomotor pathways are affected following joint injury. Corticomotor excitability alterations may not be the cause of acute changes in neuromuscular activation following joint effusion. Future research should determine whether clinically altering corticomotor excitability will improve physical function.
II.
股四头肌力量和自主激活功能缺陷在膝关节损伤后很常见。据推测，这些缺陷源于神经层面，然而，急性损伤后皮质运动通路如何受到影响仍不清楚。本研究的目的是使用实验性积液模型，检查模拟膝关节损伤后股四头肌的皮质运动是否发生改变。
参与者完成两个测试阶段，即实验性膝关节积液阶段和对照阶段，间隔7天。采用中枢激活率评估股四头肌激活的变化。通过主动运动阈值（AMT）和归一化至最大肌肉反应的运动诱发电位（MEP）在干预前后评估皮质运动兴奋性。在不同AMT百分比下评估MEP，并分析这些百分比之间的相关斜率。对从干预前结果测量计算得出的百分比变化分数进行配对样本t检验，以评估皮质运动兴奋性的变化以及随着AMT百分比增加MEP值斜率的变化。
积液阶段股四头肌激活显著降低。积液组和对照组之间的AMT和MEP变化分数没有差异。在任何AMT百分比之间的斜率上未发现实质性差异。
实验性膝关节积液未引起皮质运动兴奋性的变化。需要进一步研究以了解关节损伤后皮质运动通路如何受到影响。皮质运动兴奋性改变可能不是关节积液后神经肌肉激活急性变化的原因。未来的研究应确定临床上改变皮质运动兴奋性是否会改善身体功能。
II级。
