
Keywords: DIF، عملکرد دیفرانسیل اختیاری; Congenital muscular dystrophy; Congenital myopathy; Disability evaluation; Outcome measures; RehabilitationCM, congenital myopathy; CMD, congenital muscular dystrophy; DIF, differential item functioning; MFM, Motor Function Measure; Rs-MFM25CDM, Rasch-sca