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Updated: Jul 26, 2025
Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Generation of percentile curves for strength and functional abilities for boys with Duchenne muscular dystrophy
Mariana Angélica De Souza Leon1, Daiane Leite Da Roza2, Gabriela Barroso De Queiroz Davoli1
1Department of Health Science, Ribeirão Preto Medical School, University of São Paulo, São Paulo, Brazil.
Insights
New percentile curves for Duchenne muscular dystrophy (DMD) track functional abilities, muscle strength, and range of motion. These tools help monitor disease progression in DMD patients from age 4 to 18.
Area of Science:
- Neurology
- Pediatrics
- Genetics
Background:
- Duchenne muscular dystrophy (DMD) presents with heterogeneous clinical manifestations.
- Understanding the trajectory of functional decline is crucial for patient management.
Purpose of the Study:
- To develop percentile curves for Duchenne muscular dystrophy (DMD) using a comprehensive battery of functional measures.
- To establish reference standards for motor function, muscle strength, and range of motion in DMD patients across different ages.
Main Methods:
- Retrospective analysis of 329 patient records (ages 4-18) with DMD.
- Utilized Motor Function Measure (MFM) scale, isometric strength (IS), dorsiflexion range of motion (ROM), 10-meter walk test (10 MWT), and 6-minute walk test (6 MWT).
- Constructed percentile curves (25th, 50th, 75th) using generalized additive models.
Main Results:
- MFM percentiles demonstrated a consistent decline across all dimensions with age.
- Knee extensor strength and dorsiflexion ROM were significantly affected early (from age 4 and 8, respectively).
- 10 MWT performance time increased with age, while 6 MWT distance remained stable until age 8 before declining.
Conclusions:
- Generated age-specific percentile curves for key functional measures in DMD.
- These curves provide valuable tools for healthcare professionals and caregivers to monitor DMD disease progression.
- Facilitates standardized assessment and tracking of functional abilities in Duchenne muscular dystrophy patients.
Introduction/Aims:
Considering the heterogeneity of the clinical manifestations of Duchenne muscular dystrophy (DMD), it is important to describe their various clinical profiles. Thus, in this study we aimed to develop percentile curves for DMD using a battery of measures to define the patterns of functional abilities, timed tests, muscle strength, and range of motion (ROM).
Methods:
This retrospective data analysis was based on the records of patients with DMD using the Motor Function Measure (MFM) scale, isometric muscle strength (IS), dorsiflexion ROM, 10-meter walk test (10 MWT), and 6-minute walk test (6 MWT). Percentile curves (25th, 50th, and 75th percentiles) with MFM, IS, ROM, 10 MWT, and 6 MWT on the y axis and patient age on the x axis were constructed using the generalized additive model for location, scale, and shape, with Box-Cox power exponential distribution.
Results:
There were records of 329 assessments of patients between 4 and 18 years of age. The MFM percentiles showed a gradual reduction in all dimensions. Muscle strength and ROM percentiles showed that the knee extensors were the most affected from 4 years of age, and dorsiflexion ROM negative values were noted from the age of 8 years. The 10 MWT showed a gradual increase in performance time with age. For the 6 MWT, the distance curve remained stable until 8 years, with a subsequent progressive decline.
Discussion:
In this study we generated percentile curves that can help health professionals and caregivers follow the trajectory of disease progression in DMD patients.
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