RESUMO
OBJECTIVES: Chronic ankle instability (CAI) is associated with decreased neural excitability that negatively impacts function. This study assessed a 2-week neuromuscular electrical stimulation (NMES) or transcutaneous electrical nerve stimulation (TENS) intervention over the ankle pronators on neural excitability, performance, and patient-reported function in patients with CAI. STUDY DESIGN: Randomized controlled trial. PARTICIPANTS: Twenty participants with CAI completed the study. MAIN OUTCOME MEASURES: Participants were assessed for reflexive and corticospinal excitability to the ankle muscles, dynamic balance, side-hop test performance and patient-reported outcomes at baseline, post-intervention (2-weeks), and retention (4-weeks). Between baseline and post-intervention, participants reported for 5 sessions where they received either sub-noxious NMES (nâ¯=â¯11) or sensory-level TENS (nâ¯=â¯9) over the ankle pronators. RESULTS: Improved reflexive excitability to the ankle pronators was observed in TENS at post-intervention (pâ¯=â¯0.030) and retention (pâ¯=â¯0.029). Cortical excitability to the dorsiflexors increased in TENS at post-intervention (pâ¯=â¯0.017), but not at retention (pâ¯=â¯0.511). No significant changes were found for other neural measures, balance ability, hopping, or patient-reported function (pâ¯>â¯0.050). CONCLUSIONS: Our results suggest TENS modified neural excitability; however, these changes were not enough to impact clinical function. While TENS may be capable of neuromodulation, it may require rehabilitative exercise to generate lasting changes. NCT04322409. LEVEL OF EVIDENCE: Level 2.