Relationship between Kinesiophobia and Ankle Joint Position Sense and Postural Control in Individuals with Chronic Ankle Instability—A Cross-Sectional Study

Functional ankle instability (FAI) is a condition that causes mechanical alterations to the ankle joint and leads to disability. Fear of movement can significantly influence physical factors, and understanding their relationship is crucial in assessing and managing individuals with FAI. The present study aimed to (1) assess the impact of kinesiophobia on ankle joint position sense (JPS) and postural control and (2) evaluate if kinesiophobia can predict JPS and postural control in FAI individuals. This cross-sectional study included 55 FAI individuals. The Tampa Scale of Kinesiophobia (TSK) score was used to measure kinesiophobia. The ankle JPS was evaluated using a digital inclinometer. The individuals were asked to actively reposition to the target position of 10° and 15° of dorsiflexion and plantarflexion. The reposition accuracy is measured in degrees. The static postural control was evaluated in unilateral stance using a stabilometric force platform, including assessments for the ellipse area, anterior to posterior sway, and medial to lateral sway in mm(2). Kinesiophobia showed a significant positive correlation (moderate) with the ankle JPS errors in dorsiflexion (10°: r = 0.51, p < 0.001; at 15°: = r = 0.52, p < 0.001) and plantarflexion (10°: r = 0.35, p = 0.009; at 15°: = r = 0.37, p = 0.005). Kinesiophobia also showed significant positive (moderate) correlation with postural control variables (ellipse area: r = 0.44, p = 0.001; Anterior–Posterior sway: r = 0.32, p = 0.015; Medial–Lateral sway: r = 0.60, p < 0.001). Kinesiophobia significantly predicted ankle JPS (p < 0.05) and postural control (p < 0.05). Increased fear of movement is associated with increased ankle JPS errors and postural sway in FAI individuals. Therefore, assessment of these factors is critical in FAI individuals.