Cremoux Sylvain, Amarantini David, Tallet Jessica, Dal Maso Fabien, Berton Eric
Aix-Marseille Université, CNRS, ISM UMR 7287, Marseille, France; PRISSMH-LAPMA, Université de Toulouse, UPS, Toulouse, France; LAMIH, UMR CNRS 8201, Université de Valenciennes et du Hainaut-Cambrésis, Valenciennes, France.
Inserm, Imagerie cérébrale et handicaps neurologiques, UMR 825, Toulouse, France; Université de Toulouse, UPS, Imagerie cérébrale et handicaps neurologiques, UMR 825, Toulouse, France.
Clin Neurophysiol. 2016 Jan;127(1):629-634. doi: 10.1016/j.clinph.2015.03.016. Epub 2015 Apr 11.
After spinal cord injury (SCI), the antagonist muscles activation is increased during voluntary contractions and reflex conditioning protocols. This increase can be the result of both muscle atrophy and reciprocal facilitation mechanism. It remains however unclear to what extent increased antagonist muscles activation could be rather attributable to central vs. peripheral changes during voluntary contractions achieved by SCI participants.
We investigated the activations of elbow extensors and flexors during isometric elbow flexion and extension contractions performed at 3 force levels by 10 healthy participants and 8 participants with cervical SCI (cSCI).
At similar force level and absolute net torque in flexion, the antagonist muscles activation was increased for the participants with cSCI. At similar absolute net torque in extension, the activations of agonist and antagonist muscles were increased for the participants with cSCI.
During flexion contractions, increased antagonist muscles activation may be explained by extensors atrophy or reciprocal facilitation. During extension contractions, increased antagonist muscles activation may reflect the importance of reciprocal facilitation as antagonist muscles were evaluated as intact by clinical testing and maximal net joint torque recording.
These results in cSCI participants revealed an increased activation of antagonist muscles, which may reflect a reorganization of the spinal reflexes and their supraspinal control involved during isometric elbow contractions.
脊髓损伤（SCI）后，在自主收缩和反射调节过程中，拮抗肌的激活会增加。这种增加可能是肌肉萎缩和交互促进机制共同作用的结果。然而，目前尚不清楚在SCI患者进行自主收缩时，拮抗肌激活增加在多大程度上可归因于中枢性变化与外周性变化。
我们研究了10名健康参与者和8名颈髓损伤（cSCI）参与者在3种力水平下进行等长屈肘和伸肘收缩时，肘伸肌和屈肌的激活情况。
在相似的力水平和屈肘绝对净扭矩下，cSCI参与者的拮抗肌激活增加。在相似的伸肘绝对净扭矩下，cSCI参与者的主动肌和拮抗肌激活均增加。
在屈肘收缩过程中，拮抗肌激活增加可能由伸肌萎缩或交互促进来解释。在伸肘收缩过程中，拮抗肌激活增加可能反映了交互促进的重要性，因为通过临床测试和最大净关节扭矩记录评估拮抗肌是完整的。
这些在cSCI参与者中的结果揭示了拮抗肌激活增加，这可能反映了等长屈肘收缩过程中脊髓反射及其脊髓上控制的重组。
