Pain Catastrophizing Is Associated with Knee Function in Physically Active Individuals with Patellofemoral Pain: A Cross-Sectional Study

Background/Objectives: Patellofemoral pain (PFP) is a common and often persistent knee condition traditionally understood in biomechanical terms, though psychological factors are increasingly recognized as relevant. Pain catastrophizing has attracted particular attention, but most evidence relies on univariable associations, is drawn from female-dominated samples, and rarely tests whether catastrophizing relates to knee function after adjustment for other relevant factors. This study examined the associations between pain catastrophizing, perceived stress, body mass index (BMI), and knee pain history and knee function in physically active individuals with PFP, and whether catastrophizing remained associated with function after adjustment for the other included factors. Methods: In this cross-sectional study, 55 physically active individuals with symptoms of PFP completed the Anterior Knee Pain Scale (AKPS), the Pain Catastrophizing Scale, and the Perceived Stress Scale. BMI and knee pain history were collected. Univariable analyses were followed by a multivariable model including all four prespecified predictors. Results: In univariable analyses, higher pain catastrophizing (β = −0.48, p < 0.001), higher perceived stress (β = −0.70, p = 0.004), and higher BMI (β = −0.58, p = 0.032) were each associated with lower AKPS scores. After adjustment, only pain catastrophizing remained significant (β = −0.36, 95% CI −0.60 to −0.11, p = 0.005). The final adjusted model explained 28% of the variance in AKPS scores. Conclusions: Pain catastrophizing remained associated with poorer knee function after adjustment for perceived stress, BMI, and knee pain history, suggesting that it may warrant consideration when assessing physically active individuals with PFP.