Unilateral training of both lateral limbs increases unilateral muscle strength, whereas bilateral training increases bilateral muscle strength, a phenomenon known as lateral specificity in resistance training. Although motor imagery (MI) combined with action observation (AO) (i.e., MI + AO) training increases muscle strength, it is not completely understood whether such training increases the lateral specificity of muscle strength in a way resistance training does. To investigate whether MI + AO induces lateral specificity of muscle strength increase, 18 healthy subjects were divided into groups: MI + AO and the control groups. The control group watched a movie of natural sceneries for ten minutes per day five times a week for three weeks, whereas the MI + AO group imagined bilateral shoulder flexion while watching a movie of athletes performing bilateral shoulder flexion with barbells or dumbbells, with the same time schedule. The MI + AO group alone showed a significant increase in bilateral shoulder strength at three weeks after the intervention compared with the baseline. Unilateral shoulder strength was not significantly altered. These results suggest that MI + AO training increases muscle strength, providing evidence that similar to resistance training, lateral specificity also exists in MI + AO training.

中文翻译：

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运动图像结合动作观察训练对健康受试者肌肉力量的横向特异性的影响。

双侧肢体的单侧训练会增加单侧肌肉的力量，而双侧训练会增加双侧肌肉的力量，这种现象在阻力训练中称为侧向特异性。尽管运动图像（MI）与动作观察（AO）训练（即MI + AO）结合可以增强肌肉力量，但仍无法完全理解这种训练是否以阻力训练的方式增加了肌肉力量的侧向特异性。为了调查MI + AO是否诱导肌肉力量的横向特异性，将18名健康受试者分为MI + AO组和对照组。对照组每周五次每天观看十分钟的自然风光电影，持续三周，而MI + AO小组则在观看运动员在同一时间用杠铃或哑铃进行双侧肩部屈曲的电影时，想象双侧肩部屈曲。与基线相比，单独的MI + AO组在干预后三周显示双侧肩部力量显着增加。单侧肩部力量没有明显改变。这些结果表明，MI + AO训练可增强肌肉力量，从而提供证据表明与MI + AO训练相似，其横向特异性也存在于阻力训练中。单侧肩部力量没有明显改变。这些结果表明，MI + AO训练可增强肌肉力量，从而提供证据表明与MI + AO训练相似，其横向特异性也存在于阻力训练中。单侧肩部力量没有明显改变。这些结果表明，MI + AO训练可增强肌肉力量，从而提供证据表明与MI + AO训练相似，其横向特异性也存在于阻力训练中。