Mitsutake Tsubasa, Taniguchi Takanori, Nakazono Hisato, Yoshizuka Hisayoshi, Sakamoto Maiko
Department of Physical Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan.
Department of Occupational Therapy, Faculty of Medical Science, Fukuoka International University of Health and Welfare, Fukuoka, Japan.
Front Hum Neurosci. 2022 Jun 2;16:891669. doi: 10.3389/fnhum.2022.891669. eCollection 2022.
Noisy galvanic vestibular stimulation (nGVS) is an effective method for stabilizing posture; however, little is known regarding the detailed muscle activity and joint movement in the standing posture. This study aimed to clarify the changes in the lower limb muscle activity and joint angular velocity by nGVS intervention using the simultaneous assessment method of inertial measurement units and surface electromyography (EMG).
Seventeen healthy participants were assessed for their physical responses under four conditions (standing on a firm surface with eyes-open/eyes-closed, and a foam surface with eyes-open/eyes-closed) without stimulation (baseline) and with stimulation (sham or nGVS). Noise stimuli were applied for 30 s at a level below the perceptual threshold. The body control response was evaluated using EMG activity and angular velocity of the lower limbs.
Regarding the change from baseline for each parameter, there was a significant interactive effect of EMG activity in the muscle type × intervention and EMG activity and angular velocity in the condition × intervention. analysis revealed that the angular velocity was significantly decreased in the abduction-adduction direction in the standing on a foam surface with eyes-closed condition compared to that with eyes-open in the nGVS intervention.
Our results suggest that nGVS altered physical responses in different standing postural conditions. The present study is exploratory and therefore the evidence should be investigated in future studies specifically target those muscle activities and joint motion parameters.
噪声性前庭电刺激（nGVS）是一种稳定姿势的有效方法；然而，关于站立姿势下详细的肌肉活动和关节运动知之甚少。本研究旨在通过使用惯性测量单元和表面肌电图（EMG）同步评估方法，阐明nGVS干预对下肢肌肉活动和关节角速度的影响。
17名健康参与者在四种条件下（睁眼/闭眼站立在坚实表面上，以及睁眼/闭眼站立在泡沫表面上）接受无刺激（基线）和有刺激（假刺激或nGVS）时的身体反应评估。在低于感知阈值的水平施加30秒的噪声刺激。使用下肢的肌电活动和角速度评估身体控制反应。
关于每个参数相对于基线的变化，在肌肉类型×干预中的肌电活动以及在条件×干预中的肌电活动和角速度存在显著的交互作用。分析显示，在nGVS干预中，与睁眼相比，闭眼站立在泡沫表面上时，外展-内收方向的角速度显著降低。
我们的结果表明，nGVS改变了不同站立姿势条件下的身体反应。本研究具有探索性，因此，这些证据应在未来专门针对那些肌肉活动和关节运动参数的研究中进行调查。
