Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, 1601 SW Archer Rd (151A), Gainesville, FL 32608, USA.
Ann Biomed Eng. 2013 Aug;41(8):1778-86. doi: 10.1007/s10439-013-0832-4. Epub 2013 Jun 6.
Evidence indicates that the frequency-domain characteristics of surface electromyogram (EMG) signals are modulated according to the contributing sources of neural drive. Modulation of inter-muscular EMG synchrony within the Piper frequency band (30-60 Hz) during movement tasks has been linked to drive from the corticospinal tract. However, it is not known whether EMG synchrony is sufficiently sensitive to detect task-dependent differences in the corticospinal contribution to leg muscle activation during walking. We investigated this question in seventeen healthy older men and women. It was hypothesized that, relative to typical steady state walking, Piper band EMG synchrony of the triceps surae muscle group would be reduced for dual-task walking (because of competition for cortical resources), similar for fast walking (because walking speed is directed by an indirect locomotor pathway rather than by the corticospinal tract), and increased when taking a long step (because voluntary gait pattern modifications are directed by the corticospinal tract). Each of these hypotheses was confirmed. These findings support the use of frequency-domain analysis of EMG in future investigations into the corticospinal contribution to control of healthy and disordered human walking.
证据表明，表面肌电图（EMG）信号的频域特征根据神经驱动的贡献源进行调制。在运动任务中，Piper 频带（30-60Hz）内的肌间 EMG 同步性的调制与皮质脊髓束的驱动有关。然而，尚不清楚 EMG 同步性是否足够敏感，以检测到行走过程中皮质脊髓对腿部肌肉激活的贡献在依赖任务的差异。我们在十七名健康的老年男性和女性中研究了这个问题。假设相对于典型的稳态行走，双任务行走（由于皮质资源的竞争）时三头肌肌群组的 Piper 频带 EMG 同步性会降低，快速行走（因为行走速度是由间接运动通路而不是皮质脊髓束指导的）时相似，而当迈大步时会增加（因为自愿的步态模式修改是由皮质脊髓束指导的）。这些假设都得到了证实。这些发现支持在未来对健康和障碍性人类行走的皮质脊髓贡献进行 EMG 的频域分析。
