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.
CONCLUSION: 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.