Balance Training Does Not Alter Reliance on Visual Information during Static Stance in Those with Chronic Ankle Instability: A Systematic Review with Meta-Analysis

Background Visual, vestibular, and somatosensory systems contribute to postural control. Chronic ankle instability (CAI) patients have been observed to have a reduced ability to dynamically shift their reliance among sources of sensory information and rely more heavily on visual information during a single-limb stance relative to uninjured controls. Balance training is proven to improve postural control but there is a lack of evidence regarding the ability of balance training programs to alter the reliance on visual information in CAI patients. Objective Our objective was to determine if balance training alters the reliance on visual information during static stance in CAI patients. Methods The PubMed, CINAHL, and SPORTDiscus databases were searched from their earliest available date to October 2017 using a combination of keywords. Study inclusion criteria consisted of (1) using participants with CAI; (2) use of a balance training intervention; and (3) calculation of an objective measure of static postural control during single-limb stance with eyes open and eyes closed. Sample sizes, means, and standard deviations of single-leg balance measures for eyes-open and eyes-closed testing conditions before and after balance training were extracted from the included studies. Eyes-open to eyes-closed effect sizes [Hedges' g and 95% confidence intervals (CI)] before and after balance training were calculated, and between-study variability for heterogeneity and potential risks of publication bias were examined. Results Six studies were identified. The overall eyes-open to eyes-closed effect size difference between pre- and post-intervention assessments was not significant (Hedges' g effect size = 0.151, 95% CI = -0.151 to 0.453, p = 0.26). This result indicates that the utilization of visual information in individuals with CAI during the single-leg balance is not altered after balance training. Low heterogeneity (Q(5) = 2.96, p = 0.71, I-2 = 0%) of the included studies and no publication bias were found. Conclusion On the basis of our systematic review with meta-analysis, it appears that traditional balance training protocols do not alter the reliance on visual information used by CAI patients during a single-leg stance.