title: Quantitative muscle strength assessment in duchenne muscular dystrophy: longitudinal study and correlation with functional measures.
abstract: BACKGROUND
  The aim of this study was to perform a longitudinal assessment using Quantitative Muscle Testing (QMT) in a cohort of ambulant boys affected by Duchenne muscular dystrophy (DMD) and to correlate the results of QMT with functional measures. This study is to date the most thorough long-term evaluation of QMT in a cohort of DMD patients correlated with other measures, such as the North Star Ambulatory Assessment (NSAA) or three 6-min walk test (6MWT).
  
  
  METHODS
  This is a single centre, prospective, non-randomised, study assessing QMT using the Kin Com(®) 125 machine in a study cohort of 28 ambulant DMD boys, aged 5 to 12 years. This cohort was assessed longitudinally over a 12 months period of time with 3 monthly assessments for QMT and with assessment of functional abilities, using the NSAA and the 6MWT at baseline and at 12 months only. QMT was also used in a control group of 13 healthy age-matched boys examined at baseline and at 12 months.
  
  
  RESULTS
  There was an increase in QMT over 12 months in boys below the age of 7.5 years while in boys above the age of 7.5 years, QMT showed a significant decrease. All the average one-year changes were significantly different than those experienced by healthy controls. We also found a good correlation between quantitative tests and the other measures that was more obvious in the stronger children.
  
  
  CONCLUSIONS
  Our longitudinal data using QMT in a cohort of DMD patients suggest that this could be used as an additional tool to monitor changes, providing additional information on segmental strength.
authors.affiliation: Dipartimento di Fisiopatologia medico-chirurgica e dei Trapianti, Centro Dino Ferrari, IRCCS Istituto Auxologico Italiano, Università di Milano, Fondazione, Ospedale Maggiore Policlinico di Milano, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Lerario
authors.forename: Serena
authors.initials: S
authors.lastname: Bonfiglio
authors.forename: MariaPia
authors.initials: M
authors.lastname: Sormani
authors.forename: Andrea
authors.initials: A
authors.lastname: Tettamanti
authors.forename: Sarah
authors.initials: S
authors.lastname: Marktel
authors.forename: Sara
authors.initials: S
authors.lastname: Napolitano
authors.forename: Stefano
authors.initials: S
authors.lastname: Previtali
authors.forename: Marina
authors.initials: M
authors.lastname: Scarlato
authors.forename: MariaGrazia
authors.initials: M
authors.lastname: Natali-Sora
authors.forename: Eugenio
authors.initials: E
authors.lastname: Mercuri
authors.forename: Nereo
authors.initials: N
authors.lastname: Bresolin
authors.forename: Tiziana
authors.initials: T
authors.lastname: Mongini
authors.forename: Giancarlo
authors.initials: G
authors.lastname: Comi
authors.forename: Roberto
authors.initials: R
authors.lastname: Gatti
authors.forename: Fabio
authors.initials: F
authors.lastname: Ciceri
authors.forename: Giulio
authors.initials: G
authors.lastname: Cossu
authors.forename: Yvan
authors.initials: Y
authors.lastname: Torrente
mesh_terms: D000293:Adolescent; D002675:Child, Preschool; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D020388:Muscular Dystrophy, Duchenne / Q000175:diagnosis* / Q000503:physiopathology*; D010808:Physical Examination / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D055815:Young Adult