(1) Background: Balance decline is highly prevalent in people suffering from chronic ankle instability (CAI). The control of balance depends upon multiple neurophysiologic systems including the activation of cortical brain regions (e.g., the primary sensorimotor cortex). The excitability of this region, however, is diminished in people with CAI. In this pilot double-blinded randomized controlled trial, we tested the effects of high-definition transcranial direct current stimulation (HD-tDCS) designed to facilitate the excitability of M1 and S1 in combination with short-foot exercise (SFE) training on proprioception and dynamic balance performance in individuals with CAI. (2) Methods: Thirty young adults completed baseline assessments including the Active Movement Extent Discrimination Apparatus (AMEDA), Joint Position Reproduction (JPR) test, Y-balance test, and the Sensory Organization Test (SOT). They were then randomized to receive a four-week intervention of SFE in combination with tDCS (i.e., HD-tDCS+SFE) or sham (i.e., control) stimulation. Baseline assessments were repeated once-weekly throughout the intervention and during a two-week follow-up period. (3) Results: Twenty-eight participants completed this study. Blinding procedures were successful and no adverse events were reported. As compared to the control group, the HD-tDCS+SFE group exhibited significant improvements in the JPR test, the Y balance test, and the SOT at different time points. No group by time interaction was observed in AMEDA test performance. (4) Conclusions: HD-tDCS combined with SFE may improve dynamic balance and proprioception in CAI. Larger, more definitive trials with extended follow-up are warranted.

中文翻译：

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高清晰度经颅直流电刺激与短脚运动相结合对慢性踝关节不稳的影响：一项随机双盲试验

（1）背景：患有慢性踝关节不稳（CAI）的人中，平衡下降非常普遍。平衡的控制取决于多种神经生理系统，包括大脑皮层区域（例如初级感觉运动皮层）的激活。然而，患有CAI的人对该区域的兴奋性降低。在这项试验性双盲随机对照试验中，我们测试了高清经颅直流电刺激（HD-tDCS）的作用，旨在促进M1和S1的兴奋性，结合短脚运动（SFE）训练对本体感受和CAI患者的动态平衡表现。（2）方法：30名年轻成人完成了基线评估，包括活动活动范围鉴别仪（AMEDA），关节位置再现（JPR）测试，Y平衡测试和感觉组织测试（SOT）。然后将他们随机分组，接受为期4周的SFE与tDCS（即HD-tDCS + SFE）或假（即对照）刺激相结合的干预。在整个干预过程中，每周进行一次基线评估，并在两周的随访期内进行基线评估。（3）结果：28名参与者完成了这项研究。盲法成功，没有不良反应的报道。与对照组相比，HD-tDCS + SFE组在不同时间点的JPR测试，Y平衡测试和SOT表现出显着改善。在AMEDA测试性能中未观察到按时间分组的相互作用。（4）结论：HD-tDCS结合SFE可以改善CAI的动态平衡和本体感觉。必须进行更大范围，更明确的试验，并进行进一步的随访。