Cross-Cultural Adaptation and Content Validation of the Kannada Version of the Western Ontario Rotator Cuff Index

Objectives The study aimed to translate the Western Ontario Rotator Cuff (WORC) Index into Kannada, adapt it culturally and evaluate its content validity for use among Kannada-speaking individuals with Rotator Cuff-Related Shoulder Pain (RCRSP). Material and Methods The questionnaire was translated and culturally adapted using widely accepted Beaton’s guidelines. Two native Kannada speakers separately performed forward translation of WORC from English to Kannada, and the translated versions were then combined into a synthesised version. Following this, two native Kannada speakers who were fluent in English and unaware of the original version independently translated the synthesised Kannada version back into English. All versions were reviewed by an expert committee including four translators, the principal investigator, a senior physiotherapist and two musculoskeletal physiotherapy postgraduate students to ensure that the translations matched the original in terms of meaning, phrases and concepts. A pre-final version was prepared after making necessary modifications. The pre-final version was first given to 20 patients with shoulder pain related to rotator cuff pathology through face-to-face cognitive interviews. Following this, content validity was assessed by five physiotherapists, each with over two years of experience in treating shoulder conditions. They individually evaluated all 21 items in the questionnaire across three dimensions (relevance, clarity, and cultural appropriateness) using a five-point rating scale (5 = excellent match, 4 = very good, 3 = good, 2 = fair, 1 = poor). Item-Content Validity Index (I-CVI), Scale-Content Validity Index/Universal Agreement (S-CVI/UA), and Scale-Content Validity Index/Average (S-CVI/Ave) were calculated using a predefined threshold of I-CVI ≥0.80 and S-CVI/Ave ≥0.90. Results During the translation and cross-cultural adaptation process, three items required minor modifications: two for improved clarity and one for cultural appropriateness, without altering conceptual meaning. Pre-testing with 20 participants indicated the translation was clear and culturally appropriate. Content validity demonstrated good agreement across all three dimensions, with all items achieving I-CVI values ≥0.80 and S-CVI/Ave ≥0.90. Conclusion The Kannada version of the WORC Index has been translated, culturally adapted, and content validated for use among the Kannada-speaking population with RCRSP.