Reflexive and Perceptual Characteristics as Functional Outcome Measures of Chronic Ankle Instability.

Background: Cutaneous reflexes serve an integral role in maintaining efficient movement patterns and may be linked to sensory-perceptual deficits experienced by those with chronic ankle instability (CAI), namely, during the stance and transitional phases of the gait cycle. Abnormal reflex characteristics and perceptions of instability following unexpected perturbation have the potential to serve as potential patient-specific biomarkers for neuromuscular recovery following a lateral ankle sprain (LAS), however, these outcomes are scarcely explored.

Methods: The purpose of this retrospective case control study (level III) was to observe lower limb cutaneous reflex patterns and variability as well as perceived instability following sural nerve stimulation in those with CAI. These outcomes were measured via electromyography of 6 lower limb muscles and self-reported perceived instability as participants received random, non-noxious stimulations while walking on a treadmill.

Results: Those with CAI exhibited elevated peroneus longus facilitation and gastrocnemius reflex variability during midstance that were correlated with greater levels of perceived instability following sural stimulation.

Conclusion: These findings indicate reflex alterations may contribute to perceived instability during functional activity, a hallmark symptom of CAI.