Faculty of Health and Life Sciences, Northumbria University, Newcastle, UK.
J Electromyogr Kinesiol. 2013 Oct;23(5):1075-81. doi: 10.1016/j.jelekin.2013.04.014. Epub 2013 May 27.
Little is known regarding the modulation and the plasticity of the neural pathway interconnecting elements of the central nervous system and skeletal muscle in resistant-trained individuals. The aim of the study was to compare corticospinal and spinal responses measured during dynamic muscle contractions of the tibialis anterior in resistance trained (RT) and un-trained (UT) males. Nine UT and 10 RT male volunteers reported to the laboratory 24h following a familiarisation session. Motor evoked potentials (MEPs) and the cortical silent period were evoked using transcranial magnetic stimulation at a range of contraction intensities and was delivered as the ankle passed 90° during shortening and lengthening contractions. The Hoffmann reflex (H-reflex) and V-waves were evoked with peripheral nerve stimulation. Despite the RT group being significantly stronger during shortening (28%; P=0.023: CI=1.27-15.1Nm), lengthening (25%; P=0.041: CI=0.27-17.0Nm) and isometric muscle actions (20%; P=0.041; CI=0.77-14.9Nm), no differences between the groups existed for corticospinal or spinal variables. Lack of detectable differences between RT and UT individuals may be linked to minimal exposure to task specific, isolated high intensity resistance training of the TA muscle.
关于在经过抗阻训练的个体中，连接中枢神经系统和骨骼肌的神经通路的调制和可塑性，目前知之甚少。本研究的目的是比较抗阻训练（RT）和未经训练（UT）男性在胫骨前肌动态收缩期间测量的皮质脊髓和脊髓反应。9 名 UT 和 10 名 RT 男性志愿者在熟悉环境后 24 小时内到实验室报到。使用经颅磁刺激在一系列收缩强度下诱发运动诱发电位（MEPs）和皮质静息期，并在踝关节在缩短和延长收缩过程中通过 90°时进行传递。使用外周神经刺激诱发 Hoffmann 反射（H-反射）和 V 波。尽管 RT 组在缩短（28%；P=0.023：CI=1.27-15.1Nm）、延长（25%；P=0.041：CI=0.27-17.0Nm）和等长肌肉运动（20%；P=0.041；CI=0.77-14.9Nm）时明显更强，但在皮质脊髓或脊髓变量方面，两组之间没有差异。RT 和 UT 个体之间没有可检测到的差异，这可能与 TA 肌肉接受特定任务、孤立高强度抗阻训练的接触很少有关。
