the upper limb functional index: cross-cultural adaptation for iranian patients

Objectives: this study aimed to translate, culturally adapt, and psychometrically validate the persian version of the upper limb functional index (ulfi) in iranian patients with upper limb musculoskeletal disorders.methods: a cross-sectional study was conducted with 200 iranian outpatients diagnosed with upper limb musculoskeletal disorders. the translation and cultural adaptation process included forward translation, back-translation, expert panel review, and pilot testing. psychometric evaluation involved internal consistency (cronbach’s α), test, re-test reliability (intraclass correlation coefficient [icc]), construct validity (convergent validity with the disabilities of the arm, shoulder, and hand [dash] questionnaire), confirmatory factor analysis (cfa), and responsiveness.results: the persian ulfi exhibited excellent internal consistency (cronbach’s α=0.91) and high test re-test reliability (intraclass correlation coefficient [icc]=0.88, 95% ci, 0.82%, 0.93%). convergent validity was confirmed through a strong correlation with the dash questionnaire (r=0.76, p<0.001). cfa supported a unidimensional structure, with fit indices (comparative fit index [cfi]=0.96, tucker-lewis index [tli]=0.95, root mean square error of approximation [rmsea]=0.06, standardized root mean square residual [srmr]=0.04). responsiveness analysis demonstrated significant improvement after rehabilitation (effect size=0.89, standardized response mean [srm]=1.12, p<0.001).discussion: the persian ulfi is a valid, reliable, and responsive tool for assessing upper limb function in iranian patients. it can be effectively used in clinical settings and research to evaluate rehabilitation outcomes and functional impairment.