FACIOSCAPULOHUMERAL DYSTROPHY NATURAL-HISTORY STUDY - STANDARDIZATIONOF TESTING PROCEDURES AND RELIABILITY OF MEASUREMENTS

Background and Purpose. The natural history of facioscapulohumeral mus cular dystrophy (FSHD) has not been studied prospectively. Knowledge o f the natural progression of any disease provides essential informatio n for the design of clinical trials. We present a protocol for the stu dy of the natural history of FSHD using quantitative muscle testing (Q MT), manual muscle testing (MMT), and functional testing Subjects. Thi rty-two persons with FSHD (mean age=361 years, SD=9.6, range=17-49) an d 32 age- and gender-matched volunteer controls (mean age=35.8 years, SD=8.0, range=23-50) served as subjects Methods. Using standardized te sting procedures, we examined intrarater reliability of the MMT, QMT, and functional testing measurements in both groups We also examined in terrater reliability in 7 subjects with FSHD. Eighteen muscle groups w ere tested for each subject using QMT and MMT Results. Intraclass corr elation coefficient (ICC) values ranged from .86 to .99 for intrarater reliability and from .86 to.99 for interrater reliability of QMT meas urements. Weighted kappa values of .81 to .98 for intrarater reliabili ty and.50 to 1.00 for interrater reliability were obtained for MMT mea surements. Intrarater ICCs for various functional testing measures ran ged from .69 to .97 In addition, the comparability of the two QMT mach ines used in the study was demonstrated by testing the same set of vol unteer controls on each machine's linear force transducer (ICC=.89-.98 ). Conclusion and Discussion. We conclude that this standardized testi ng protocol produces reliable measurements of muscle strength and func tional ability in subjects with FSHD.