Cross cultural adaptation and psychometric properties of the Persian version of the fear of return to sport scale: a cross-sectional validation study

Patient-reported outcome measures (PROMs) are increasingly used in rehabilitation research to assess psychological factors related to recovery and return to sport. The Fear of Return to Sport Scale (FRESS) is a recently developed and psychometrically validated instrument for measuring fear of returning to sport. This study aimed to translate and cross-culturally adapt the FRESS to Persian (FRESS-Persian) and evaluate its reliability and validity among injured athletes. The FRESS was translated and cross-culturally adapted into Persian, following international guidelines. A total of 123 injured athletes completed the questionnaire. Reliability and validity were evaluated using Cronbach’s alpha, intraclass correlation coefficient (ICC), standard error of measurement, minimal detectable change, and exploratory and confirmatory factor analyses. Convergent and divergent validity were assessed by examining correlations with pain intensity, the Tampa Scale for Kinesiophobia (TSK), and the Injury-Psychological Readiness to Return to Sport Scale (I-PRRS). The FRESS-Persian demonstrated good internal consistency (α = 0.895) and good test–retest reliability (ICC = 0.774, 95% CI: 0.662–0.852). Exploratory factor analysis supported a one-factor structure explaining 57.75% of the variance. Confirmatory factor analysis supported the proposed model, although the RMSEA exceeded the recommended threshold. Factor loadings ranged from 0.692 to 0.851. The FRESS-Persian showed significant positive correlations with pain intensity ( r = 0.347) and TSK scores ( r = 0.283), and a significant negative correlation with I-PRRS scores ( r =-0.527). No floor or ceiling effects were observed. The findings support the reliability and validity of the FRESS-Persian for assessing fear of return to sport in this sample of Persian-speaking athletes following injury.