Neuromuscular Electrical Stimulation of Peroneal Longus on Balance Control Ability in Young Adults with Chronic Ankle Instability: A Randomized Controlled Trial

Abstract Objective This study aimed to investigate the effects of six weeks of peroneal longus neuromuscular electrical stimulation (NMES) on the balance control ability in young adults with chronic ankle instability (CAI). Design This study is a double blind randomized controlled trial. Six weeks of NMES and placebo intervention were conducted in the NMES and control groups for 20 minutes, three times a week, respectively. Thirty-eight participants successfully completed the whole intervention and single-leg standing tests. The kinetics data of the center of pressure (COP) trajectory during static single-leg stance were measured using a Kistler force platform. Two-way repeated measures ANOVA was used to analyze the electrical stimulation effects. Results Significant interactions were detected in CAIT scores and all balance parameters including Displacement X (Dx), Displacement Y(Dy), 95% confidence ellipse area (95%AREA), root-mean-square (RMS) and COP mean displacement velocity (MV) (p < 0.05, 0.103 ≤ η2 ≤ 0.201). Significant between-group differences were found in CAIT scores (p = 0.003, Cohen’s d = 0.215), Dx (p = 0.045, Cohen’s d = 0.107), RMS-ml (p = 0.019, Cohen’s d = 0.143) and 95%AREA (p = 0.031, Cohen’s d = 0.123) after the six weeks interventions. Conclusion Six weeks of NMES on the peroneus longus can improve static balance control ability in young adults with CAI, especially the stability of ankle frontal plane.