Effects of Combining High-Definition Transcranial Direct Current Stimulation with Short-Foot Exercise on Chronic Ankle Instability: A Pilot Randomized and Double-Blinded Study

Yuanbo Ma,Yong Jiang,Yu Liu,Brad Manor,Jin Huang,Wei Zhuang,Keyi Yin,Junhong Zhou,Cui Zhang

doi:10.3390/brainsci10100749

Abstract

(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.

Highlights

Chronic ankle instability (CAI) is highly prevalent in people who have suffered an ankle sprain [1,2]and is characterized by recurrent ankle sprains, the perception of the ankle “giving-way,” and long-term functional impairment [3]
Inclusion criteria were: (1) self-reported history of the first acute ankle sprain more than one year ago; (2) experience of two or more sprains to the same ankle in the three months prior to study; (3) at least two episodes of slack or ‘giving-way’ associated with the same ankle in the six months prior to participation; (4) a Cumberland Ankle Instability Tool (CAIT) score less than 24 [18]; and (5) the ability to stand or walk for at least
Another participant withdrew due to insufficient time needed to complete the study protocol

Summary

Introduction

Chronic ankle instability (CAI) is highly prevalent in people who have suffered an ankle sprain [1,2]and is characterized by recurrent ankle sprains, the perception of the ankle “giving-way,” and long-term functional impairment [3]. Chronic ankle instability (CAI) is highly prevalent in people who have suffered an ankle sprain [1,2]. Traditional rehabilitation for CAI focuses primarily on peripheral neuromuscular function of the ankle [6]. Both spinal and supraspinal elements of the central nervous system play an important role in the regulation of sensation and balance [7]. Ankle joint sensation and proprioception require afferent information arising from mechanoreceptors to be delivered via peripheral, spinal, and subcortical nerve pathways to sensorimotor cortical networks in the brain. CAI diminishes the quantity and quality of afferent information and results in altered activation of these cortical networks

Methods

Results

Conclusion