cross-cultural adaptation of the micheli functional scale to persian language for evaluation of low back pain in the young athletes

Background: a clinical outcome tool is needed for the assessment of young athletes with low back pain. objectives: to translate and culturally adapt the micheli functional scale (mfs), a self-report questionnaire developed to evaluate young athletes with low back pain (lbp) into persian language and examine the reliability and validity of the persian mfs (pmfs). materials and methods: a cross-sectional study was conducted to assess the psychometric properties of the pmfs. the pmfs was cross- culturally adapted into persian language adopting forward/backward translation, expert panel review, and pre-testing. the pmfs was administered to young athletes with and without lbp. main outcome measures were persian mfs, persian functional rating index (pfri), and visual analogue scale (vas). results: a sample of 100 young athletes with lbp with a mean age of 16.5 ± 2.5 years participated. fifty young athletes without lbp completed the pmfs. there was no missing responses and floor or ceiling effects. there was a significant difference for the total pmfs scores between young athletes with and without lbp. a significant correlation was found between the total pmfs score and the vas (r = 0.92) or the pfri (r = 0.82; p < 0.001). a high internal consistency reliability (cronbach α = 0.73), and excellent test-retest reliability (iccagreement = 0.99, p < 0.001) were demonstrated for the pmfs. factor analysis indicated a single-factor model for pmfs scores. conclusions: the persian mfs is valid and reliable for use in persian-speaking young athletes with lbp.