Abstract

FMRI studies support that neuromuscular electrical stimulation can modulate the excitability of the somatosensory cortex. We studied whether practice and electrical stimulation of the quadriceps would enhance learning during a weight-bearing task. 20 healthy individuals (10 male) and 8 control subjects participated in a 2-day study. Day 1 consisted of a pretest, a training session, and a post-test; day 2 consisted of a pretest, 2 bouts of electrical stimulation to the quadriceps muscles, and a post-test. The single limb squat task was performed at varying knee resistance and target velocities and a random unexpected perturbation was administered. Feedforward error was calculated during a 50 ms time window before the unexpected event. Feedback error was calculated during a 150 ms window after the unexpected event. Peak error score decreased by 2.98 degrees (p < 0.001) immediately following training. Error was improved by 1.78 degrees (p < 0.001) during the feedforward phase and 1.44 degrees (p < 0.001) during the feedback phase. All subjects plateaued after day 1; except for the electrical stimulation group that showed a decrease of 1.206 degrees during the perturbed cycles (p = 0.024). Electrical stimulation triggered additional learning, beyond practice, during the unexpected event at a latency associated with the transcortical reflex.

摘要

FMRI 研究支持神经肌肉电刺激可以调节躯体感觉皮层的兴奋性。我们研究了股四头肌的练习和电刺激是否会在负重任务中增强学习能力。20 名健康个体（10 名男性）和 8 名对照受试者参加了为期 2 天的研究。第 1 天包括前测、培训课程和后测；第 2 天包括前测、2 次股四头肌电刺激和后测。单肢深蹲任务是在不同的膝关节阻力和目标速度下进行的，并进行了随机的意外扰动。前馈误差是在意外事件发生前的 50 ms 时间窗口内计算的。反馈误差是在意外事件发生后的 150 毫秒窗口内计算的。峰值错误分数降低了 2。p  < 0.001) 训练后立即。 前馈阶段误差改善了 1.78 度 ( p < 0.001)  ，反馈阶段误差改善了1.44 度 ( p < 0.001)。所有受试者在第 1 天后趋于稳定；除了电刺激组在扰动周期中下降 1.206 度（p  = 0.024）。在与经皮层反射相关的潜伏期的意外事件期间，电刺激引发了额外的学习，超出了实践。