Balance disorders are a risk factor for falls in the elderly population. Balance control involving the complex interaction among nervous, muscular, and sensory systems should be maintained to keep an upright posture and prevent falls. Vestibular sensation is one of the main senses essential for postural control. Noisy galvanic vestibular stimulation (nGVS) is a noninvasive stimulation method for vestibular organs. Recently, it has received increasing attention for the treatment of balance disorders. However, the effect of balance disorders on stimulus effect during the implementation of nGVS remains unknown. Therefore, this study aimed to determine the effects of different floor surface and visual conditions on the stimulus effects of the nGVS intervention. In this study, two experiments were conducted with 24 participants (12 each for Experiments 1 and 2). In Experiment 1, nGVS (0.4 mA; 0.1–640 Hz) was performed in the open-eyes standing position on a solid surface (nGVS condition) and in the closed-eye standing position on a foam rubber (nGVS + foam rubber condition). In Experiment 2, sham stimulation was performed under the same conditions as in Experiment 1, except for nGVS. Center of pressure (COP) sway was measured in all participants with them standing with open eyes at Pre and Post-1 (immediately after the intervention) and Post-2 (10 min after the measurement of post-1). In Experiment 1, under the nGVS condition, COP sway was significantly reduced in Post-1 and Post-2 compared with Pre. However, no significant difference was observed among Pre, Post-1, and Post-2 under the nGVS + foam rubber condition. Furthermore, the intervention effect was significantly greater in the nGVS condition than in the nGVS + foam rubber condition. In contrast, in Experiment 2, the COP sway did not significantly differ among Pre, Post-1, and Post-2 under either condition. Based on the results of this study, nGVS was found to be effective with open-eyes standing on a solid surface.

中文翻译：

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不同刺激条件对噪声前庭电刺激刺激效果的影响

平衡障碍是老年人跌倒的危险因素。应保持涉及神经、肌肉和感觉系统之间复杂相互作用的平衡控制，以保持直立姿势并防止跌倒。前庭感觉是姿势控制必不可少的主要感觉之一。噪声前庭电刺激 (nGVS) 是一种针对前庭器官的无创刺激方法。最近，它在治疗平衡障碍方面受到越来越多的关注。然而，平衡障碍对 nGVS 实施过程中刺激效果的影响仍然未知。因此，本研究旨在确定不同地板表面和视觉条件对 nGVS 干预刺激效果的影响。在这项研究中，对 24 名参与者进行了两项实验（实验 1 和 2 各 12 人）。在实验 1 中，nGVS (0.4 mA; 0.1–640 Hz) 在固体表面上的睁眼站立位置（nGVS 条件）和在泡沫橡胶上的闭眼站立位置（nGVS + 泡沫橡胶条件）进行. 在实验 2 中，除了 nGVS 之外，在与实验 1 相同的条件下进行假刺激。在所有参与者中测量压力中心 (COP) 摇摆，他们在 Pre 和 Post-1（干预后立即）和 Post-2（在测量 post-1 后 10 分钟）睁眼站立。在实验 1 中，在 nGVS 条件下，与 Pre 相比，Post-1 和 Post-2 的 COP 摆动显着降低。然而，在 nGVS + 泡沫橡胶条件下，Pre、Post-1 和 Post-2 之间没有观察到显着差异。此外，nGVS 条件下的干预效果明显大于 nGVS + 泡沫橡胶条件下的干预效果。相比之下，在实验 2 中，在任一条件下，前、后 1 和后 2 之间的 COP 摇摆没有显着差异。根据这项研究的结果，发现 nGVS 对站立在固体表面上的睁眼很有效。