Effectiveness of balance training in people with chronic ankle instability: An Umbrella review with meta-meta-analysis.

BackgroundChronic ankle instability (CAI) is a common sequela of lateral ankle sprains and is characterized by proprioceptive deficits, impaired postural control, and functional limitations. Balance training (BT) is widely prescribed in rehabilitation; however, the magnitude and consistency of its effects remain uncertain.ObjectiveTo synthesize and critically evaluate evidence from systematic reviews and meta-analyses that assess the effectiveness of balance training in adults with CAI.MethodsAn umbrella review of systematic reviews, with or without meta-analyses, was conducted. PubMed, Web of Science (WoS), Scopus, and ScienceDirect were searched up to November 1, 2025. Methodological quality was assessed using AMSTAR 2, risk of bias was assessed using ROBIS, and certainty of evidence was assessed using GRADE. When possible, a meta-analysis was performed using a random-effects model with Hartung-Knapp adjustment. Effect sizes were expressed as Hedges' g (95% CI) and heterogeneity was assessed using I2 and τ2.ResultsTwenty-seven systematic reviews were included, of which five contributed quantitative data (25 individual studies; n = 1,821 adults). Dynamic postural control showed a significant pooled effect favoring BT over the control group (Hedges' g = 0.91; 95% CI 0.41-1.41; high heterogeneity). Additional comparisons demonstrated significant advantages for BT over control and visual-occlusion-augmented training, whereas vibration-only protocols outperformed combined BT + vibration training in isolated analyses. An outlier influence was identified in the primary study. Static balance outcomes have been inconsistently reported across reviews and cannot be quantitatively synthesized. No meta-analytic data were available for pain, ankle range of motion (ROM), muscle strength, or health-related quality of life owing to insufficient or heterogeneous reporting. The overall certainty of evidence for dynamic postural control was rated as moderate according to the GRADE.ConclusionsBalance training provides moderate certainty evidence for improving dynamic postural control in adults with CAI. Evidence of static balance and broader functional outcomes remains limited, with substantial methodological heterogeneity across reviews. These findings should be interpreted cautiously, and high-quality randomized trials with standardized protocols and long-term follow-up are required to strengthen the clinical evidence base.