Askari Sina, Kamgar Parisa, Chao TeKang, Diaz Eric, de Leon Ray D, Won Deborah S
Biomedical Engineering Department, University of Southern California, Los Angeles, CA 90007, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2012;2012:1855-8. doi: 10.1109/EMBC.2012.6346313.
While neuromuscular electrical stimulation (NMES) has enabled patients of neuromotor dysfunction to effectively regain some functions, analysis of neuromuscular changes underlying these functional improvements is lacking. We have developed an NMES system for a rodent model of SCI with the long term goal of creating a therapy which restores control over stepping back to the spinal circuitry. NMES was applied to the tibialis anterior (TA) and timed to the afferent feedback generated during robotic treadmill training (RTT). The effect of NMES+RTT on modifications in EMG was compared with that of RTT alone. A longitudinal study with a crossover design was conducted in which group 1 (n=7) received 2 weeks of RTT only followed by 2 weeks of NMES+RTT; group 2 (n=7) received 2 weeks of NMES+RTT followed by RTT only. On average, both types of training helped to modulate TA EMG activity over a gait cycle, resulting in EMG profiles across steps with peaks occurring just before or at the beginning of the swing phase, when ankle flexion is most needed. However, NMES+RTT resulted in concentration of EMG activation during the initial swing phase more than RTT only. In conjunction with these improvements in EMG activation presented here, a more complete analyses comparing changes after NMES+RTT vs. RTT is expected to further support the notion that NMES timed appropriately to hindlimb stepping could help to reinforce the motor learning that is induced by afferent activity generated by treadmill training.
虽然神经肌肉电刺激（NMES）已使神经运动功能障碍患者能够有效恢复一些功能，但缺乏对这些功能改善背后的神经肌肉变化的分析。我们已经为脊髓损伤的啮齿动物模型开发了一种NMES系统，其长期目标是创建一种疗法，使对踏步的控制恢复到脊髓回路。将NMES应用于胫前肌（TA），并根据机器人跑步机训练（RTT）期间产生的传入反馈进行定时。将NMES+RTT对肌电图（EMG）改变的影响与单纯RTT的影响进行比较。进行了一项交叉设计的纵向研究，其中第1组（n=7）仅接受2周的RTT，然后接受2周的NMES+RTT；第2组（n=7）先接受2周的NMES+RTT，然后仅接受RTT。平均而言，两种类型的训练都有助于在一个步态周期内调节TA的EMG活动，从而在各步中形成EMG图谱，其峰值出现在摆动期之前或开始时，此时最需要踝关节屈曲。然而，与单纯RTT相比，NMES+RTT在初始摆动期导致EMG激活更加集中。结合本文所述的EMG激活方面的这些改善，对NMES+RTT与RTT后的变化进行更全面的分析，有望进一步支持以下观点，即与后肢踏步适当同步的NMES有助于加强由跑步机训练产生的传入活动所诱导的运动学习。
