title: Clinical evaluator reliability for quantitative and manual muscle testing measures of strength in children.
abstract: Measurements of muscle strength in clinical trials of Duchenne muscular dystrophy have relied heavily on manual muscle testing (MMT). The high level of intra- and interrater variability of MMT compromises clinical study results. We compared the reliability of 12 clinical evaluators in performing MMT and quantitative muscle testing (QMT) on 12 children with muscular dystrophy. QMT was reliable, with an interclass correlation coefficient (ICC) of >0.9 for biceps and grip strength, and >0.8 for quadriceps strength. Training of both subjects and evaluators was easily accomplished. MMT was not as reliable, and required repeated training of evaluators to bring all groups to an ICC >0.75 for shoulder abduction, elbow and hip flexion, knee extension, and ankle dorsiflexion. We conclude that QMT shows greater reliability and is easier to implement than MMT. Consequently, QMT will be a superior measure of strength for use in pediatric, neuromuscular, multicenter clinical trials.
authors.affiliation: Children's National Medical Center, Washington, DC, USA.
authors.forename: D M
authors.initials: DM
authors.lastname: Escolar
authors.forename: E K
authors.initials: EK
authors.lastname: Henricson
authors.forename: J
authors.initials: J
authors.lastname: Mayhew
authors.forename: J
authors.initials: J
authors.lastname: Florence
authors.forename: R
authors.initials: R
authors.lastname: Leshner
authors.forename: K M
authors.initials: KM
authors.lastname: Patel
authors.forename: P R
authors.initials: PR
authors.lastname: Clemens
mesh_terms: D002648:Child; D006225:Hand; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D007596:Joints / Q000503:physiopathology; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology*; D009136:Muscular Dystrophies / Q000503:physiopathology*; D020388:Muscular Dystrophy, Duchenne / Q000503:physiopathology; D015588:Observer Variation; D015203:Reproducibility of Results