Abstract
BACKGROUND: The Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale measures psychological readiness to return to sport after an anterior cruciate ligament (ACL) injury or ACL reconstruction (ACLR). The 6-item short version of this scale has demonstrated psychometric properties similar to those of the original 12-item version. PURPOSE: To translate the short ACL-RSI scale into Thai and assess its psychometric properties via the COSMIN (COnsensus-based Standards for the selection of health Measurement INstruments) checklist. STUDY DESIGN: Cohort study (Diagnosis); Level of evidence, 3. METHODS: This prospective cohort study was conducted from August 2022 to April 2024. The Thai version of the short ACL-RSI scale was translated according to international guidelines. A psychometric evaluation was performed on athletes aged 18 to 50 years who had undergone ACLR at 6 months to 5 years prior. Participants completed the study questionnaires at baseline and 2 weeks later. The construct validity of the Thai version of the short ACL-RSI scale was evaluated by testing predefined hypotheses regarding its associations with other assessment tools. Reliability was assessed using internal consistency, test-retest reliability, and measurement error. Interpretability was assessed based on floor and ceiling effects and the minimal important change. RESULTS: The short ACL-RSI scale was successfully translated into Thai. A total of 142 participants (mean age, 30.7 ± 8.9 years; 83.1% male) were included. Overall, 8 of 9 (88.9%) predefined hypotheses were confirmed, supporting good construct validity. The scale demonstrated good internal consistency (Cronbach alpha = 0.88) and test-retest reliability (intraclass correlation coefficient = 0.79). No floor or ceiling effects were observed. The minimal important change, which was calculated via a distribution-based method, was 9.2 points. CONCLUSION: The study demonstrated that the Thai version of the short ACL-RSI scale is a valid and reliable tool for assessing psychological readiness to return to sport after ACLR.