Exploratory Analysis of Unstable Surface Training: A Systematic Review and Meta-Analysis for Chronic Ankle Instability.

Objective: To conduct an exploratory systematic review and meta-analysis to evaluate the effect of unstable surface training on balance and hop function in individuals with chronic ankle instability (CAI).

Data Sources: Four major electronic databases were searched, including Cochrane Library, PubMed, Embase, and Web of Science, from January 1, 2000 to June 20, 2024.

Study Selection: Randomized controlled trials that compare unstable surface training with either general intervention or no intervention in individuals with CAI were included.

Data Extraction: The physical therapy evidence database scale was used to assess the risk of bias and methodological quality of included studies. The mean differences (MDs) with 95% confidence intervals (CIs) were calculated using Review Manager 5.4 software.

Data Synthesis: The review ultimately included 9 studies involving 308 participants. Compared with the other exercises or no exercise, unstable surface training could improve the significant effects of the star excursion balance test (SEBT) in the direction of posterolateral (MD=5.80; 95% CI, 1.60-9.99; P=.007), posteromedial (MD=6.24; 95% CI, 2.32-10.16; P=.002), medial (MD=9.11; 95% CI, 6.42-11.80; P<.00001), anteromedial (MD=7.25; 95% CI, 2.33-12.17; P=.004), the time-in-balance test (MD=8.45; 95% CI, 1.50-15.40; P=.02), the foot-lift test (MD=-1.39; 95% CI, -2.49 to -0.28; P=.01). However, there was no significant difference in the anterior direction of the SEBT (MD=3.22; 95% CI, -0.66 to 7.10; P=.10), the side-hop test (MD=-1.94; 95% CI, -4.82 to 0.95; P=.19), and the figure-of-8 hop test (MD=-0.97; 95% CI, -2.39 to 0.46; P=.18) between groups.

Conclusions: Compared with the other exercises or no exercise, unstable surface training has potential benefits in improving balance in people with CAI but has no significant effect on hop function. However, the exploratory nature of this study highlights the need for further research to confirm these findings.