Neuromuscular electrical stimulation combined with dynamic multidirectional therapeutic exercise for chronic ankle instability: Effects on neuromuscular activation and functional outcomes.

Objectives
To compare the effects of a 4-week dynamic, multidirectional therapeutic exercise (TEx) programme alone versus TEx combined with neuromuscular electrical stimulation (NMES) in individuals with chronic ankle instability (CAI).

Design
Randomised intervention study.

Setting
Laboratory.

Participants
Twenty physically active adults with CAI.

Main Outcome Measures
Participants were randomised to either a TEx group or an NMES group. Both groups completed the same 4-week dynamic, multidirectional therapeutic exercise programme, while the NMES group received bilateral peroneal stimulation during exercise sessions. Outcomes included the Cumberland Ankle Instability Tool (CAIT), the Lower Quadrant Y-Balance Test (LQ-YBT), and lower-limb muscle activation latency during inversion-simulation and drop-jump tasks.

Results
Both groups improved CAIT scores post-intervention (p<0.001), although only NMES maintained improvements at follow-up (p<0.001). NMES demonstrated greater reductions in inversion-related muscle activation latency across multiple muscles, including tibialis anterior and peroneus longus (p<0.05). Within-group improvements in posteromedial, posterolateral, and composite LQ-YBT scores were observed in the TEx group (p<0.05). Drop-jump outcomes demonstrated variable changes between groups.

Conclusions
NMES combined with TEx may improve the timing of neuromuscular activation during inversion-simulation tasks, while TEx showed within-group improvements in some dynamic balance outcomes.