ObjectiveThe objectives of the study were to (1) determine the association between kinesiophobia and lumbar joint position sense (JPS) in individuals with chronic low back pain (CLBP); (2) examine the relationship between kinesiophobia and postural stability in individuals with CLBP; and (3) investigate whether pain intensity mediates the relationship between kinesiophobia, lumbar JPS, and postural stability in individuals with CLBP. MethodsIn this cross-sectional study, a total of 83 individuals diagnosed with CLBP were included. The level of fear of movement was assessed using the Tampa Scale for Kinesiophobia (TSK). Lumbar JPS was measured using the active target repositioning technique, which involved evaluating JPS in 3 directions: lumbar flexion, side-bending to the left, and side-bending to the right. The repositioning accuracy of the lumbar joint was quantified in degrees using a dual digital inclinometer. Postural stability was assessed using a stabilometric force platform, which measured anterior to posterior (A-P) sway, medial to lateral (M-L) sway, and the ellipse area in mm². ResultsThe findings of this study revealed a statistically significant and moderate positive correlation between kinesiophobia and lumbar JPS in various directions, including flexion (r = 0.51, P < .001), side-bending to the left (r = 0.37, P = .001), and side-bending to the right (r = 0.34, P = .002). Similarly, a significant positive association was observed between kinesiophobia and postural stability, as indicated by the correlation coefficients: A-P sway (r = .47, P < .001), M-L sway (r = 0.58, P < .001), and ellipse area (r = 0.51, P < .001). Furthermore, the analysis revealed that pain significantly mediated the relationship between kinesiophobia and both lumbar JPS (P < .05) and postural stability (P < .05). These findings were demonstrated through mediation analysis. ConclusionsThis study identified a significant association between kinesiophobia, lumbar JPS, and postural stability. Additionally, we observed the presence of pain as a potential mediator in this relationship. However, it is important to note that our cross-sectional study design precludes establishing causality or determining the direct mediation effect of pain on adverse outcomes.