Omofuma Isirame, Carrera Robert, King-Ori Jayson, Agrawal Sunil K
Mechanical Engineering Department, Columbia University, New York, NY, USA.
Deployment Roboticist, Covariant AI, Emeryville, CA, USA.
Wearable Technol. 2024 Feb 8;5:e3. doi: 10.1017/wtc.2023.24. eCollection 2024.
Transcutaneous spinal cord stimulation (TSCS) is gaining popularity as a noninvasive alternative to epidural stimulation. However, there is still much to learn about its effects and utility in assisting recovery of motor control. In this study, we applied TSCS to healthy subjects concurrently performing a functional training task to study its effects during a training intervention. We first carried out neurophysiological tests to characterize the H-reflex, H-reflex recovery, and posterior root muscle reflex thresholds, and then conducted balance tests, first without TSCS and then with TSCS. Balance tests included trunk perturbations in forward, backward, left, and right directions, and subjects' balance was characterized by their response to force perturbations. A balance training task involved the subjects playing a catch-and-throw game in virtual reality (VR) while receiving trunk perturbations and TSCS. Balance tests with and without TSCS were conducted after the VR training to measure subjects' post-training balance characteristics and then neurophysiological tests were carried out again. Statistical comparisons using t-tests between the balance and neurophysiological data collected before and after the VR training intervention found that the immediate effect of TSCS was to increase muscle activity during forward perturbations and to reduce balance performance in that direction. Muscle activity decreased after training and even more once TSCS was turned off. We thus observed an interaction of effects where TSCS increased muscle activity while the physical training decreased it.
经皮脊髓刺激（TSCS）作为硬膜外刺激的一种非侵入性替代方法正越来越受欢迎。然而，关于其在协助运动控制恢复方面的效果和效用仍有许多需要了解的地方。在本研究中，我们将TSCS应用于同时进行功能训练任务的健康受试者，以研究其在训练干预期间的效果。我们首先进行神经生理学测试，以表征H反射、H反射恢复和后根肌肉反射阈值，然后进行平衡测试，先在无TSCS的情况下进行，然后在有TSCS的情况下进行。平衡测试包括向前、向后、向左和向右方向的躯干扰动，受试者的平衡通过他们对力扰动的反应来表征。一项平衡训练任务要求受试者在虚拟现实（VR）中玩接球和投球游戏，同时接受躯干扰动和TSCS。在VR训练后进行有无TSCS的平衡测试，以测量受试者训练后的平衡特征，然后再次进行神经生理学测试。使用t检验对VR训练干预前后收集的平衡和神经生理学数据进行统计比较发现，TSCS的即时效果是在向前扰动期间增加肌肉活动，并降低该方向的平衡表现。训练后肌肉活动减少，在TSCS关闭后减少得更多。因此，我们观察到了一种效果的相互作用，即TSCS增加肌肉活动，而体育训练则降低肌肉活动。
