Neuromuscular electrical stimulation improves stability and function in chronic ankle instability: a systematic review and meta-analysis

Chronic ankle instability (CAI) commonly develops following lateral ankle sprains and is associated with recurrent sprains, persistent pain, and neuromuscular deficits. While neuromuscular electrical stimulation (NMES) has shown promising results in enhancing muscle strength and neuromuscular control, its specific effects on CAI remain insufficiently investigated. A comprehensive search of electronic databases was conducted to identify randomized controlled trials (RCTs) evaluating NMES interventions in individuals with CAI. Studies were included if they reported outcomes related to instability, balance (both static and dynamic), and functional recovery. Pooled data were analyzed using weighted mean differences (WMDs) or standardized mean differences (SMDs), with heterogeneity assessed using the I² statistic. Seven RCTs involving 248 participants were included in the analysis. NMES significantly improved self-reported instability (WMD = 2.18; 95% CI: 1.21 to 3.14; p < 0.01), static balance (WMD = − 1.43; 95% CI: − 2.80 to − 0.06; p = 0.04), dynamic balance (SMD = 0.73; 95% CI: 0.40 to 1.06; p < 0.01), and functional recovery (SMD = 0.40; 95% CI: 0.01 to 0.80; p = 0.04) compared to control groups. NMES shows promise as an adjunctive therapy for CAI. However, given the observed heterogeneity and methodological limitations, current evidence warrants cautious interpretation. Further rigorous, sham-controlled trials are essential to validate long-term efficacy. PROSPERO (CRD420251101522).