Xiao Songlin, Wang Baofeng, Zhang Xini, Zhou Junhong, Fu Weijie
Key Laboratory of Exercise and Health Sciences of Ministry of Education, Shanghai University of Sport, Shanghai, China.
The Hinda and Arthur Marcus Institute for Aging Research, Hebrew SeniorLife, Boston, MA, United States.
Front Bioeng Biotechnol. 2022 Jun 1;10:894131. doi: 10.3389/fbioe.2022.894131. eCollection 2022.
This study aimed to examine the effects of 4 weeks of high-definition transcranial direct current stimulation (HD-tDCS) and foot core exercise (FCE) on foot sensorimotor function (i.e., toe flexor strength and passive ankle kinesthesia) and postural control. In total, 36 participants were randomly assigned into three groups as follows: HD-tDCS, FCE, and the control group. A total of 12 training sessions were performed over 4 weeks (i.e., three sessions per week) in the laboratory. The HD-tDCS group received 20-min HD-tDCS with a current density of 2 mA, and the FCE group completed short foot exercise, towel curls, toe spread and squeeze, and balance board training. Participants in the control group just maintained the activities what they usually did and did not receive any interventions. Foot muscle strength, passive ankle kinesthesia, and postural control were assessed at baseline and post-intervention. HD-tDCS induced a greater decrease in the percentage changes in the passive kinesthesia thresholds of ankle inversion ( < 0.001) and eversion ( = 0.013) than the control group. Compared with the control group, a significant increase in the percentage change in the metatarsophalangeal joint flexor strength was found in the HD-tDCS group ( = 0.008) and the FCE group ( = 0.027), and a significant increase in the percentage change in toe flexor strength was observed in the FCE group ( = 0.015). Moreover, FCE induced a greater reduction in the percent changes in the medial-lateral average center of gravity sway velocity in one-leg standing with eyes open ( = 0.033) and the anteroposterior average center of gravity sway velocity in one-leg standing with eyes closed ( < 0.001) than control. This study demonstrated that 4 weeks of HD-tDCS and FCE induced distinct benefits on foot sensorimotor function and the standing postural control performance in healthy young adults. HD-tDCS could improve the metatarsophalangeal joint flexor strength and the passive kinesthesia thresholds of ankle inversion and eversion. Meanwhile, FCE could also enhance foot muscle strength and enhance postural control performance in one-leg standing.
本研究旨在探讨4周的高清经颅直流电刺激（HD-tDCS）和足部核心运动（FCE）对足部感觉运动功能（即趾屈肌力量和被动踝关节感觉）及姿势控制的影响。总共36名参与者被随机分为以下三组：HD-tDCS组、FCE组和对照组。在实验室中，4周内共进行了12次训练课程（即每周三次）。HD-tDCS组接受了20分钟、电流密度为2毫安的HD-tDCS，FCE组完成了短足运动、毛巾卷曲、脚趾伸展和挤压以及平衡板训练。对照组的参与者仅维持其日常活动，未接受任何干预。在基线和干预后评估足部肌肉力量、被动踝关节感觉和姿势控制。与对照组相比，HD-tDCS组在踝关节内翻（<0.001）和外翻（=0.013）被动感觉阈值的百分比变化上有更大幅度的降低。与对照组相比，HD-tDCS组（=0.008）和FCE组（=0.027）在跖趾关节屈肌力量的百分比变化上有显著增加，FCE组在趾屈肌力量的百分比变化上有显著增加（=0.015）。此外，与对照组相比，FCE在睁眼单腿站立时的内外侧平均重心摆动速度百分比变化（=0.033）和闭眼单腿站立时的前后平均重心摆动速度百分比变化（<0.001）上有更大幅度的降低。本研究表明，4周的HD-tDCS和FCE对健康年轻成年人的足部感觉运动功能和站立姿势控制表现有明显益处。HD-tDCS可改善跖趾关节屈肌力量以及踝关节内翻和外翻的被动感觉阈值。同时，FCE也可增强足部肌肉力量并提高单腿站立时的姿势控制表现。
