Introduction: Chronic ankle instability (CAI), which is characterized by deficient postural control, is associated with functional limitations and diminished self-reported quality of life. Recent studies have suggested that balance training can improve postural control, but high-quality evidence-based research to confirm the effect of balance training on dynamic postural stability in CAI patients is lacking. The purpose of this study was to synthesize current evidence regarding the effect of balance training on dynamic postural stability in CAI patients.
Evidence acquisition: PubMed, Embase, Web of Science and Cochrane Library databases were searched for clinical trials that evaluated the effect of balance training on posture and balance in CAI patients from their inception to 15 July 2021. All statistical analyses were performed in RevMan 5.4. The risk of bias was assessed by the Cochrane Collaboration's risk of bias tool, and studies that reported statistically comparable outcomes were analyzed in meta-analyses using random effects models. Heterogeneity was assessed using the I2 statistic index.
Evidence synthesis: A total of 12 RCTs included in this meta-analysis and revealed that balance training was effective for improving the dynamic posture stability of CAI patients (SMD=0:90; 95% CI: 0.54 to 1.26; P<0:00001, I2=71%; Star Excursion Balance Test). Subgroup analysis (balance training vs. other training) revealed a small negative effect size, but this was not statistically significant (SMD=-0.12, 95% CI=-0.53 to 0.29, P=0.56, I2=9%). Another subgroup analysis (balance training vs. no training) revealed that balance training was more likely to have greater improvement on the dynamic posture stability of CAI patients (SMD=0.94, 95% CI: 0.71 to 1.17; P<0.00001, I2=0%).
Conclusions: Balance training yielded a statistically significant and clinically meaningful improvement in dynamic postural stability in CAI patients. Limited evidence indicates that balance training was more effective than other training methods.