Exercise combined with electrical stimulation for the treatment of chronic ankle instability - A randomized controlled trial

Purpose: To compare the short, medium, and long-term effects of balance exercises combined with either peroneal neuromuscular electrical stimulation (NMES) or peroneal transcutaneous electrical nerve stimulation (TENS) on dynamic postural control and patient reported outcome measures (PROMs) in patients with chronic ankle instability (CAI). Methods: Thirty-four participants with CAI were randomly assigned to a 12-session home based exercise program combined with NMES (Ex-NMES) or TENS (Ex- TENS). Baseline postural control was tested with the modified Star Excursion Balance Test (mSEBT) and time to stabilization (TTS) after a single-leg drop-jump. The selfreported function was measured using the Cumberland Ankle Instability Tool (CAIT), the Identification of Functional Ankle Instability (IdFAI), and the Sports subscale of the Foot and Ankle Ability Measure (FAAMSport). Results: Both groups showed significant improvements in all self-reported outcome measures at the 12-month follow-up. Subjects in the Ex-NMES group had significantly better IdFAI (-4.2 [95% CI -8.1, -0.2]) and FAAMSport (13.7 [95% CI 2.2, 25.2]) scores at 6- and 12-month follow-up, respectively, compared to the Ex-TENS group. Medium to large between-group effect sizes were observed in self-reported functional outcomes and the mSEBT. Conclusion: The consistent trend of improvement in self-reported functional outcomes when training is combined with NMES compared with training with TENS may indicate a potential benefit that should be further investigated as a treatment for patients with CAI.