Translation, Cross-Cultural Adaptation, and Validation of the Italian Version of the Shoulder Instability—Return to Sport After Injury (SI-RSI) Scale.

Objective: To culturally adapt and validate the Italian version of the Shoulder Instability—Return to Sport after Injury (SI-RSI-I) scale. Methods: The SI-RSI-I was developed by adapting the Anterior Cruciate Ligament—Return to Sport Index—Italian version and replacing the term "knee" with "shoulder." Subsequently, it underwent validation following COSMIN recommendations. The study involved athletic participants who experienced SI. They completed the SI-RSI-I together with other measurement instruments: Western Ontario Shoulder Instability Index, Kerlan-Jobe Orthopedic Clinic Score, EuroQol-5D-5L, and Numeric Pain Rating Scale. The following psychometric properties were investigated: structural validity, internal consistency, test–retest reliability, measurement error, and construct validity. Results: The study included 101 participants (age mean [SD] 28.5 [7.4] y; 83 males, 18 females). The SI-RSI-I showed a single-factor structure, excellent internal consistency (α =.935), and excellent test–retest reliability (ICC =.926; 95% CI,.853–.964). The standard error of measurement was 6.1 points, and the minimal detectable change was 17.0 points. Furthermore, SI-RSI-I demonstrated moderate to strong correlations with all reference scales, confirming 8 out of 9 (88.0%) hypotheses, thus establishing satisfactory construct validity. Conclusion: The SI-RSI-I has demonstrated robust internal consistency, reliability, validity, and feasibility as a valuable scale for assessing psychological readiness to return to sport in Italian athletes with SI. [ABSTRACT FROM AUTHOR]