Effectiveness of backward walking training on balance performance: A systematic review and meta-analysis

Background: Backward walking (BW) training is thought to impact balance performance through improving motor system proprioception and gait characteristic, but relevant evidence remains sparse and inconclusive. Objective: This study systematically reviewed and quantified the scientific evidence regarding the effectiveness of BW training on balance performance. Methods: Keyword and reference search on BW training interventions was conducted in six electronic databases (PubMed, Web of science, SPORTDiscus, CINAHL, Cochrane Library, and CNKI) for peer-reviewed articles published till November 2017. A standardized form was used to extract data from each selected article that met the pre-specified eligibility criteria. Meta-analysis was conducted to estimate the pooled effects of BW training on balance performance measures. Results: Eleven studies (nine randomized controlled trials and two pre-post studies) met the eligibility criteria and were included in the review. All studies reported some beneficial effects of BW training on balance performance. Compared to control, BW training was associated with a reduction in overall stability index score by 0.99 (95% CI = 0.37, 1.61; I ² = 0.0%; fixed-effect model), medial-lateral stability index score by 0.95 (95% CI = 0.34, 1.57; I ² = 0.0%; fixed-effect model), and anterior-posterior stability index score by 0.99 (95% CI = 0.37, 1.61; I ² = 0.0%; fixed-effect model). Meanwhile, BW training was associated with an increase in open-eyes single leg standing duration by 0.91 s (95% CI = 0.29, 1.53; I ² = 75.9%; random-effect model) in comparison to control. Conclusions: BW training could serve as a potentially useful tool to improve balance performance among those with a high risk of fall. However, current evidence remains preliminary due to the small cohort of studies and possible learning effect in pre-post studies. Future work with larger scale and randomized experimental design is warranted to evaluate the effectiveness of BW training on balance performance across diverse population and disease subgroups, and elucidate the underlying biomechanical and neurological pathways.