Lebon F, Rouffet D, Collet C, Guillot A
Université de Lyon, Université Claude Bernard Lyon 1, Centre de Recherche et d'Innovation sur le Sport (C.R.I.S.) EA 647, Laboratoire de la Performance Motrice, Mentale et du Matériel (P3M), France.
Neurosci Lett. 2008 Apr 25;435(3):181-5. doi: 10.1016/j.neulet.2008.02.033. Epub 2008 Mar 10.
To provide evidence that motor imagery (MI) is accompanied by improvement of intramuscular conduction velocity (CV), we investigated surface electromyographic (EMG) activity of 3 muscles during the elbow flexion/extension. Thirty right-handed participants were asked to lift or to imagine lifting a weighted dumbbell under 3 types of muscular contractions, i.e. concentric, isometric and eccentric, taken as independent variables. The EMG activity of the agonist (long and short heads of biceps brachii) and the antagonist (long portion of triceps brachii) muscles was recorded and processed to determine the median frequency (MF) of EMG power spectrum as dependant variable. The MF was significantly higher during the MI sessions than during the resting condition while the participants remained strictly motionless. Moreover, the MF during imagined concentric contraction was significantly higher than during the eccentric. Thus, the MF variation was correlated to the type of contraction the muscle produced. During MI, the EMG patterns corresponding to each type of muscle contraction remained comparable to those observed during actual movement. In conclusion, specific motor programming is hypothesized to be performed as a function of muscle contraction type during MI.
为了提供运动想象（MI）伴随着肌肉内传导速度（CV）改善的证据，我们研究了3块肌肉在肘关节屈伸过程中的表面肌电图（EMG）活动。30名右利手参与者被要求在3种肌肉收缩类型（即向心收缩、等长收缩和离心收缩）下作为自变量提起或想象提起一个哑铃。记录并处理了主动肌（肱二头肌长头和短头）和拮抗肌（肱三头肌长头）的肌电图活动，以确定肌电图功率谱的中位数频率（MF）作为因变量。在运动想象期间，参与者保持完全静止时，MF显著高于静息状态。此外，想象向心收缩期间的MF显著高于离心收缩期间。因此，MF变化与肌肉产生的收缩类型相关。在运动想象期间，对应于每种肌肉收缩类型的肌电图模式与实际运动期间观察到的模式保持相似。总之，假设在运动想象期间会根据肌肉收缩类型执行特定的运动编程。
