PURPOSE: The Anterior Cruciate Ligament Return to Sports after Injury scale (ACL-RSI) has been translated and culturally adapted into the Thai version. This study aimed to evaluate the reliability and validity of the Thai ACL-RSI for athletes recovering from ACL reconstruction. METHODS: This study was a cross-sectional study. Forward-backward translation, cultural adaptation, and validation of the Thai ACL-RSI were performed and tested in 40 athletes (8 females, 32 males
mean age 30.2 ± 7.32 years
mean body weight 70.7 ± 13.36 kg
mean height 170.1 ± 6.53 cm
mean body mass index 24.5 ± 3.74 kg/m RESULTS: The Thai ACL-RSI demonstrated commendable content validity (item-objective congruence index [IOC] 0.91), internal consistency (Cronbach's alpha coefficient 0.84), and test-retest reliability (intraclass correlation coefficient [ICC] 0.75). There was a significant negative correlation with TSK (r = -0.67, p <
0.001). CONCLUSION: The Thai ACL-RSI is validated, reliable, and consistent with the Thai TSK. This instrument can potentially measure psychological factors influencing preparedness for sports participation after ACL reconstruction. The evaluation of return-to-sport readiness should involve a multidisciplinary approach, including surgeons, physiotherapists, and psychologists, to ensure a comprehensive assessment of physical, functional, and psychological factors.