Effect of Otago Exercise Program Combined with Neuromuscular Electrical Stimulation on Chronic Ankle Instability in Older Adults: A Pilot Randomized Controlled Trial

<b>Background</b>: Chronic ankle instability (CAI) is a common functional disorder in older adults, affecting their balance and quality of life. Therefore, finding effective ways to enhance ankle stability and function under safe conditions remains a key issue for healthy aging. <b>Objective</b>: This study aims to explore the effects of the Otago Exercise Program (OEP) combined with Neuromuscular Electrical Stimulation (NMES) on ankle stability, the pain index, and balance ability in older adults aged 60 and above with CAI. <b>Methods</b>: This study is a single-blind pilot randomized controlled trial, including 36 eligible older adults with CAI, with 34 completing the trial. Participants were randomly assigned to the OEP group, the combined group (OEP + NMES), and the control group. The intervention period lasted 8 weeks. Evaluation measures included the Cumberland Ankle Instability Tool (CAIT), Visual Analog Scale (VAS), Eyes-closed Single-Leg Stance Test (UST), and the Modified Star Excursion Balance Test (mSEBT), with assessments conducted before the intervention, at week 4, and at week 8. <b>Result</b>: After the intervention, all three groups showed significant improvements in CAIT, VAS, UST, and mSEBT scores (<i>p</i> < 0.05), with a large group × time effect observed for the primary outcome CAIT (partial η² = 0.414). The combined group (OEP + NMES) demonstrated the most significant improvement in CAIT and UST scores (<i>p</i> < 0.05) and outperformed the other two groups in dynamic balance in the posteromedial and posterolateral directions. <b>Conclusions</b>: The combined intervention of OEP and NMES significantly improves ankle stability, both static and dynamic balance abilities, and alleviates pain in older adults with CAI. This combined approach offers a safe and effective rehabilitation strategy for the older adults, with promising clinical application prospects.