Validity and reliability of the Thai functional internal rotation scale for shoulder arthroplasty.

Background: The Functional Internal Rotation Scale is an excellent clinical tool for evaluating patients with shoulder arthroplasty, but it has not been adapted to the Thai version. The objectives of this study were to translate the English version and culturally adapt the Functional Internal Rotation Scale to the Thai version and to examine the psychometric properties of the Thai Functional Internal Rotation Scale among Thai participants having shoulder arthroplasty.

Methods: The Functional Internal Rotation Scale was translated to Thai, including cross-cultural adaptations, following standard guidelines.