The Investigation of Nonlinear Variability Underlying Postural Control in The Injure-Limb in Individuals with and without Chronic Ankle Instability

Background: Less flexible and adaptable sensorimotor systems reflect in movement variability in individuals with Chronic Ankle Instability (CAI), which may limit their ability to detect relevant information using a variety of primary sensory feedback. Thus, the aim of the study was to investigate underlying biological noise pertaining to postural control in single-limb stance during increased environmental constraints with sensory feedback manipulations in individuals with and without CAI. Methods: Forty-two individuals with and without CAI participated in the study. A one-way ANOVA was utilized to examine group differences in biological noise underlying postural control during the SOT conditions in single-limb stance. Results: Individuals with CAI demonstrated significantly lower SampEN while maintaining posture during Condition 5 (P=.037) and Condition 6 (P=.030), where they were forced to exclusively rely on vestibular feedback, in single-limb stance compared to healthy controls. Discussion: Individuals with CAI did not demonstrate decreased movement variability pertaining to postural control during all six SOT conditions. Those participants with CAI only displayed decreased movement variability when they were forced to executively rely on vestibular feedback while maintaining posture in the injured-limb compared to healthy controls.