Lockyer Evan J, Nippard Anna P, Kean Kaitlyn, Hollohan Nicole, Button Duane C, Power Kevin E
Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1C5S7, Canada.
School of Human Kinetics and Recreation, Memorial University of Newfoundland, St. John's, NL A1C5S7, Canada.
Brain Sci. 2019 Feb 14;9(2):41. doi: 10.3390/brainsci9020041.
The present study compared corticospinal excitability to the biceps brachii muscle during arm cycling at a self-selected and a fixed cadence (SSC and FC, respectively). We hypothesized that corticospinal excitability would not be different between the two conditions.
The SSC was initially performed and the cycling cadence was recorded every 5 s for one minute. The average cadence of the SSC cycling trial was then used as a target for the FC of cycling that the participants were instructed to maintain. The motor evoked potentials (MEPs) elicited via transcranial magnetic stimulation (TMS) of the motor cortex were recorded from the biceps brachii during each trial of SSC and FC arm cycling.
Corticospinal excitability, as assessed via normalized MEP amplitudes (MEPs were made relative to a maximal compound muscle action potential), was not different between groups.
Focusing on maintaining a fixed cadence during arm cycling does not influence corticospinal excitability, as assessed via TMS-evoked MEPs.
本研究比较了在自选节奏和固定节奏（分别为SSC和FC）的手臂骑行过程中，皮质脊髓对肱二头肌的兴奋性。我们假设在这两种情况下皮质脊髓兴奋性没有差异。
首先进行SSC，每5秒记录一次骑行节奏，持续一分钟。然后将SSC骑行试验的平均节奏用作参与者被要求保持的FC骑行目标。在SSC和FC手臂骑行的每次试验中，通过对运动皮层进行经颅磁刺激（TMS）引出的运动诱发电位（MEP）从肱二头肌记录下来。
通过标准化MEP波幅评估的皮质脊髓兴奋性（MEP相对于最大复合肌肉动作电位）在各组之间没有差异。
如通过TMS诱发的MEP所评估的，专注于在手臂骑行过程中保持固定节奏不会影响皮质脊髓兴奋性。
