Reliability of reflex measurements and perceived instability following cutaneous stimulation during gait

Individuals with chronic ankle instability (CAI) exhibit a variety of sensorimotor deficits which contribute to long-term health risks and lower overall health-related quality of life. Recent literature finds abnormal cutaneous reflex characteristics and perceptions of instability during gait among those with CAI. These may serve as important patient-specific outcome measures in diagnosing and monitoring the condition, however, the test-retest reliability of these measurements is still undetermined. Therefore, the purpose of this study is to assess reliability of cutaneous reflex amplitudes and variability and perceived instability following perturbation in those with CAI and healthy controls during gait. Subjects walked on a treadmill while receiving random, non-noxious sural nerve stimulations throughout the stance phases of gait. Muscle activity was measured via electromyography for the peroneus longus, and medial and lateral gastrocnemius. Subjects reported their perceived instability following each stimulation. Cutaneous reflex amplitudes and perceived instability throughout the stance phases of gait can be reliably measured within the same day and over a 1-week period while reflex variability may be a less reliable measure. Our findings support the use of these variables as clinical outcome measures to identify and monitor neuromuscular recovery.