Effects of Low-Load Blood Flow Restriction Exercise combined with Proprioceptive Training on Ankle Strength and Balance in Adults with Chronic Ankle Instability

Background Ankle sprains occur frequently across all ages and sexes, and some individuals progress to chronic ankle instability (CAI), which is characterized by muscle weakness, impaired proprioception, and decreased postural control. Recently, blood flow restriction exercise (BFR) has gained increasing attention in musculoskeletal rehabilitation. However, research on the effects of low-load blood flow restriction exercise (LL-BFR) combined with proprioceptive training in individuals with CAI remains limited. Purpose This study aimed to investigate the effects of LL-BFR combined with proprioceptive training on ankle muscle strength and balance in adults with CAI. Study design A randomized comparative study with two groups using a pre-post design Methods This study involved 26 adults with CAI, who were randomly assigned to two groups of 13 participants each. The experimental group performed LL-BFR combined with proprioceptive training, while the control group performed traditional high-load resistance training (HLRT) combined with proprioceptive training. The time × group interaction effects were analyzed using a two-way mixed measures ANOVA, with the statistical significance level (α) set at 0.05. Results Both groups showed significant pre- to post-intervention improvements in ankle dorsiflexion, plantarflexion, and eversion strength (p <0.05), whereas no significant change was observed in inversion strength (p > 0.05). For dynamic balance, significant improvements were found in both the limit of stability and the Y-Balance Test (YBT) in both groups (p <0.05). A significant time × group interaction was observed for the YBT; however, post hoc analyses indicated that although the control group demonstrated a greater magnitude of improvement than the experimental group, the between-group difference did not remain statistically significant after Bonferroni correction (p = 0.044). Conclusions LL-BFR significantly improved ankle muscle strength and dynamic balance in individuals with CAI; however, it did not demonstrate superiority over traditional HLRT across most outcomes. Therefore, LL-BFR may be considered as an adjunctive or alternative intervention for individuals unable to perform high-load resistance exercise.