AI 中文总结
该研究以28名健康成年人为对象，探究tSCS的效应，发现其破坏有意识踝关节本体感觉、使步态更受限，且经刺激下训练可改善本体感觉并重塑运动控制。
AI 中文摘要
经皮脊髓刺激（tSCS）主要通过激活传入网络调节脊髓感觉运动回路。尽管先前的研究已关注运动表现和脊髓兴奋性，但tSCS如何影响有意识的本体感觉，以及这种影响在多大程度上与运动控制的变化平行，仍不清楚。我们调查了tSCS对健康成年人（n=14）踝关节本体感觉和步态的急性效应及训练相关效应，另有独立对照组（n=14）在无刺激情况下完成相同的本体感觉训练。本体感觉通过双侧机器人踝关节动态定位能力评估（Crisscross）量化， gross motor output通过最大背屈力量评估，正常和串联跑步机行走时的步态通过时空参数、躯干摆动和内外侧重心（CoM）偏移量评估。急性tSCS使踝关节本体感觉误差增大（p<0.001），而背屈力量无变化（p=0.30）。步态向适度更受限的运动模式转变，表现为步宽和内外侧CoM偏移量减小（p<0.05）。在刺激下持续训练后，本体感觉误差减小，且与对照组不同，tSCS组表现出持续改善，该改善在刺激结束后仍存在。矢状面步态指标恢复至基线水平或超过基线，而内外侧指标仍保持受限，揭示了运动控制的方向依赖性重组。综上，这些发现表明tSCS影响感觉运动控制回路的多个方面，破坏有意识本体感觉的同时重塑运动行为，且神经系统可通过训练适应改变的传入输入。
英文摘要
Transcutaneous spinal cord stimulation (tSCS) modulates spinal sensorimotor circuits primarily through activation of afferent networks. While prior work has emphasized locomotor performance and spinal excitability, how tSCS affects conscious proprioceptive perception and the extent to which such effects parallel changes in locomotor control remain unclear. We investigated the acute and training-related effects of tSCS on ankle proprioception and gait in unimpaired adults (n = 14), with an independent control group (n = 14) completing identical proprioceptive training without stimulation. Proprioception was quantified using a bilateral robotic assessment of dynamic ankle localization ability (Crisscross), gross motor output using maximum dorsiflexion strength, and gait during normal and tandem treadmill walking using spatiotemporal, trunk-sway, and mediolateral center-of-mass (CoM) excursion measures. Acute tSCS increased ankle proprioceptive error (p < 0.001) while dorsiflexion strength was unchanged (p = 0.30). Gait shifted toward a modestly more constrained locomotor pattern, characterized by reduced step width and ML CoM excursion (p < 0.05). With continued training under stimulation, proprioceptive error decreased and, unlike the control group, the tSCS group showed progressive improvement that persisted after stimulation ended. Sagittal-plane gait measures recovered toward or beyond baseline, whereas mediolateral measures remained constrained, revealing a direction-dependent reorganization of locomotor control. Together, these findings show that tSCS influences multiple aspects of the sensorimotor control loop, disrupting conscious proprioception while reshaping locomotor behavior, and that the nervous system can adapt to altered afferent input through training.
