Neural activation of the triceps surae is impaired following 2 weeks of immobilization
Neural activation of the triceps surae is impaired following 2 weeks of immobilization
复制标题
DOI：
10.1007/s00421-004-1225-z
复制
发表时间：
2004-12-01
影响因子：
3
通讯作者：
Martin, A
中科院分区：
文献类型：
--
作者：
Gondin, J;Guette, M;Martin, A
本研究的目的是研究踝关节制动2周对小腿三头肌神经活动的影响，特别是单关节比目鱼肌和双关节腓肠肌之间的潜在差异。17名男性志愿者随机分为固定组(n=8)和对照组(n=9)。仅使用弹性胶带和踝关节稳定矫形器固定踝关节。测量最大自主收缩(MVC)时以及静息时单刺激、成对刺激和强直刺激后的足底屈肌扭矩。记录比目鱼肌和腓肠肌的相关肌电活动，并通过抽动内插技术估计它们的激活程度。制动后，小腿三头肌最大自主扭矩显著下降17%(P<；0.001)。强度损失伴随着激活水平(-6%，所用三种技术的平均值)和最大100赫兹强直力(-11%)的降低。比目鱼肌的肌电活动显著降低(-22%，P<；0.05)，但腓肠肌的肌电活动(归一化为相应的M波)没有明显下降。结论：制动后自主扭矩输出减少可归因于肌肉和神经的改变。后者选择性地累及单关节比目鱼肌，而保留了对双关节腓肠肌的神经驱动，而腓肠肌作为膝关节屈肌的功能尚未被固定。
The purpose of this study was to investigate the effect of 2 weeks of ankle joint immobilization on triceps surae neural activation, with particular emphasis on the potential differences between the monoarticular soleus and the biarticular gastrocnemius muscles. Seventeen male volunteers were divided into the immobilized group (IG, n = 8) and the control group (CG, n = 9). Elastic adhesive bandages and an ankle stabilization orthosis were used to immobilize the ankle joint only. The plantar flexor torque obtained during maximal voluntary contractions (MVC) and after single, paired and tetanic stimuli applied at rest was measured. The associated EMG activity from the soleus and gastrocnemius muscles was also recorded, and their activation levels were estimated by means of the twitch interpolation technique. After immobilization, triceps surae maximal voluntary torque significantly decreased by 17% ( P< 0.001). Strength losses were accompanied by a decrement in activation level ( - 6%, average of the three techniques used) and in maximal 100 Hz tetanic force ( - 11%). A significant decrease in the soleus ( - 22%, P< 0.05) but not in the gastrocnemius EMG activity, normalized to respective M-waves, was also found. It was concluded that the reduced voluntary torque output after immobilization could be attributed to both muscular and neural alterations. These latter selectively involved the monoarticular soleus muscle, while neural drive to the biarticular gastrocnemii, which had not been immobilized in their function as knee flexors, was preserved.