École de Kinésiologie et des Sciences de l'Activité Physique, Université de Montréal, Montréal, Canada.
LAMIH, UMR CNRS 8201, Université de Valenciennes et du Hainaut Cambrésis, Valenciennes, France.
Eur J Neurosci. 2018 Nov;48(10):3288-3298. doi: 10.1111/ejn.14126. Epub 2018 Oct 10.
During isometric contractions, the net joint torque stability is modulated with the force production phases, i.e., increasing (IFP), holding (HFP), and decreasing force (DFP) phases. It was hypothesized that this modulation results from an altered cortical control of agonist and antagonist muscle activations. Eleven healthy participants performed 50 submaximal isometric ankle plantar flexion contractions. The force production phase effect (IFP, HFP and DFP) was assessed on the net joint torque stability, agonist and antagonist muscles activations, cortical activation, and corticomuscular coherence (CMC) with agonist and antagonist muscles. In comparison to HFP, the net joint torque stability, the agonist muscles activation and the CMC with agonist muscles were lower during IFP and even more during DFP. Antagonist muscle activations, cortical activations and CMC with antagonist muscles were higher during HFP than during IFP only. Increased CMC with agonist and antagonist muscles appeared to enhance the fine motor control. At a cortical level, agonist and antagonist muscle activations seemed to be controlled independently according to their muscle function and the phase of force production. Results revealed that CMC was an adequate measure to investigate the cortical regulation of agonist and antagonist muscle activations. This may have potential applications for patients with altered muscle activations.
在等长收缩期间，净关节扭矩稳定性通过力产生阶段进行调节，即增加（IFP）、保持（HFP）和减少力（DFP）阶段。假设这种调制是由于对激动剂和拮抗剂肌肉激活的皮层控制发生改变所致。11 名健康参与者进行了 50 次次最大等长踝关节跖屈收缩。在净关节扭矩稳定性、激动剂和拮抗剂肌肉激活、皮层激活以及与激动剂和拮抗剂肌肉的皮质肌相干（CMC）方面，评估了力产生阶段效应（IFP、HFP 和 DFP）。与 HFP 相比，IFP 期间净关节扭矩稳定性、激动剂肌肉激活和与激动剂肌肉的 CMC 降低，而 DFP 期间甚至更低。拮抗剂肌肉激活、皮层激活和与拮抗剂肌肉的 CMC 在 HFP 期间高于 IFP 期间。增加的与激动剂和拮抗剂肌肉的 CMC 似乎增强了精细运动控制。在皮层水平上，根据肌肉功能和力产生阶段，似乎可以独立控制激动剂和拮抗剂肌肉的激活。结果表明，CMC 是研究激动剂和拮抗剂肌肉激活的皮层调节的有效措施。这可能对肌肉激活改变的患者具有潜在的应用价值。
