Cross-Cultural Adaptation and Validation of the Persian Version of the Functional Arm Scale for Throwers

Background: The Functional Arm Scale for Throwers (FAST) is a reliable and valid region-specific tool designed to evaluate health-related quality of life in throwing athletes with upper-extremity injuries. The purpose of this study was to adapt, translate, and evaluate the psychometric properties of the Persian version of the Functional Arm Scale (FAST-Persian) for use in throwing athletes.Materials and Methods: The study was conducted based on 5 steps of cross-cultural adaptation including forward translation, synthesis, backward translation, expert committee review, and pretesting. The final Persian questionnaire, along with Persian versions of Disabilities of the Arm, Shoulder, and Hand and Kerlan-Jobe Orthopedic Clinic questionnaires, was completed by 177 throwing athletes for validity analysis. After 7 to 14 days, the FAST-Persian was reanswered by 80 throwers, who had no changes in this time interval. Internal consistency and test retest reliability were used to evaluate reliability of the questionnaire. Standard error of measurement and smallest detectable changes were also calculated. Construct validity was determined by correlational analysis with Disabilities of the Arm, Shoulder, and Hand and Kerlan-Jobe Orthopedic Clinic questionnaires. Dimensionality was evaluated with factor analysis.Result: Cronbachs alpha was .99, and the interclass correlation coefficient levels for total score and 5 subscales of the FAST-Persian ranged between .98 and .99. The standard error of measurement and smallest detectable changes were 3.17 and 8.80, respectively. The FAST-Persian had a high correlation with Disabilities of the Arm, Shoulder, and Hand (r = .98, P < .0001) and Kerlan-Jobe Orthopedic Clinic (r = .98, P < .0001) scores. Factor analysis revealed one factor with a total variance of 75.23%.Conclusion: The FAST-Persian is a reliable and valid measurement tool that can be used to evaluate health-related quality of life in overhead athletes and throwers.