cross-cultural adaptation, validity and reliability of the persian version of the kerlan-jobe orthopedic clinic shoulder and elbow score

Introduction: shoulder injuries among overhead athletes are common, often occurring during sports activities. these injuries challenge the effectiveness of general shoulder function assessment tools like the dash and ases. the purpose of this study was to evaluate the validity and reliability of the persian-translated kerlan-jobe orthopaedic clinic (kjoc) questionnaire, which is specifically designed to assess shoulder function in overhead athletes.materials and methods: ethical clearance facilitated the linguistic and cultural adaptation of the original english version of the kjoc questionnaire into persian. the study involved 100 iranian overhead athletes (72 males, 28 females; mean age: 26.2±7.1 years) who participated in volleyball, water polo, and badminton. the persian-translated kjoc was subjected to a rigorous translation process, followed by content validity assessment using the content validity ratio (cvr) and content validity index (cvi). reliability was assessed through internal consistency using cronbach’s alpha (α) and test-retest reliability using the intraclass correlation coefficient (icc).results: the content validity of the persian-translated kjoc was confirmed with a cvr of 0.79 and a cvi of 0.85, indicating its necessity, clarity, and relevance. internal consistency, measured by cronbach’s α, was found to be excellent (α=0.947), and test-retest reliability, measured by icc, demonstrated excellent consistency (icc=0.903). the mean total scores of participants at the first and second administrations were 66.79±24.36 and 65.23±23.74, respectively, one week apart without any intervention, demonstrating the stability of the tool.conclusion: the persian-translated kjoc questionnaire exhibited excellent validity and reliability, confirming its suitability as a reliable tool for evaluating shoulder function and performance in overhead athletes. while the tool shows promise, the study acknowledges some limitations, such as the lack of construct validity assessment, ceiling/floor effect analysis, and the heterogeneous nature of the athlete pool.