Modulation of muscle activity and force fluctuations in the plantarflexors after bedrest depends on knee position.
Modulation of muscle activity and force fluctuations in the plantarflexors after bedrest depends on knee position.
复制标题
卧床休息后肌肉活动的调节和跖屈肌的力量波动取决于膝盖的位置。
DOI：
10.1002/mus.20764
复制
发表时间：
2007
期刊：
影响因子：
3.4
通讯作者：
Shinohara,Minoru
中科院分区：
文献类型：
--
作者：
Yoshitake,Yasuhide;Kouzaki,Motoki;Fukuoka,Hideoki;Fukunaga,Tetsuo;Shinohara,Minoru
腿部肌肉的力量波动在卧床休息后增加，这可能是由于特定于肌肉或激动剂肌肉共同的神经策略的调制。本研究的目的是检查在膝关节屈曲（FLX）和伸展（EXT）位置卧床休息后，在稳定收缩期间，跖屈肌肌肉参与程度不同，肌肉活动和力量波动的调节。在20天卧床休息前后，在稳定的等长收缩期间测量5名年轻男性内侧腓肠肌（MG）、外侧腓肠肌和比目鱼肌的跖屈力和表面肌电图（EMG）。在EXT中，MG卧床后整流肌电图≤10 Hz的功率显著增加。MG中肌肉活动的这种低频调制伴随着力的标准差增加29%。其他肌肉的EMG无变化。在FLX中，没有对EMG或力波动进行调整。这些结果表明，MG的低频调制在卧床休息后EXT稳定跖屈期间增加力波动方面发挥作用。研究结果表明，在卧床休息后稳定收缩期间，神经策略的调节具有任务/肌肉特异性，并强调了针对特定任务/肌肉设计特定训练方案的重要性。肌肉神经，2007年
Force fluctuations in leg muscles increase after bedrest, perhaps due to modulation of the neural strategy that is specific to a muscle or common to agonist muscles. The purpose of this study was to examine the modulation of muscle activity and force fluctuations during steady contractions with variable involvement of plantarflexor muscles after bedrest at knee‐flexed (FLX) and extended (EXT) positions. Before and after 20‐day bedrest, plantarflexion force and surface electromyogram (EMG) in the medial gastrocnemius (MG), lateral gastrocnemius, and soleus muscles were measured during steady isometric contractions in five young men. In EXT, power ≤10 HZin the rectified EMG of MG increased significantly after bedrest. This low‐frequency modulation of muscle activity in MG accompanied a 29% increase in the standard deviation of force. There was no change in EMG in other muscles. In FLX, there was no adjustment in EMG or force fluctuations. These results suggest that low‐frequency modulation of MG plays a role in increasing force fluctuations during steady plantarflexion in EXT after bedrest. The findings indicate task/muscle specificity in the modulation of neural strategy during steady contractions after bedrest and underscore the importance of designing a specific training regimen targeted to particular tasks/muscles with regard to force fluctuations in multiple‐agonist systems. Muscle Nerve, 2007