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Updated: Nov 30, 2025
Measurements of Motor Function and Other Clinical Outcome Parameters in Ambulant Children with Duchenne Muscular Dystrophy
Published on: January 12, 2019
Walking activity in a large cohort of boys with Duchenne muscular dystrophy
Donovan J Lott1, Tanja Taivassalo2, Claudia R Senesac1
1Department of Physical Therapy, University of Florida, College of Public Health & Health Professions, Gainesville, Florida, USA.
Insights
Step activity in boys with Duchenne muscular dystrophy (DMD) declines with age and predicts functional ability. Higher baseline walking activity is linked to sustained ambulation over time, offering insights for clinical trials.
Area of Science:
- Pediatrics
- Neuromuscular Disorders
- Biomedical Engineering
Background:
- Duchenne muscular dystrophy (DMD) is a progressive genetic disorder affecting muscle function.
- Understanding ambulatory activity is crucial for assessing disease progression and treatment efficacy in DMD.
- Current methods for evaluating functional decline in DMD may not fully capture real-world activity levels.
Purpose of the Study:
- To investigate walking activity patterns in a cohort of boys with DMD.
- To determine the relationship between step activity, functional ability, and strength in DMD.
- To assess the predictive value of baseline step activity on long-term ambulatory status.
Main Methods:
- Quantified daily step activity over 7 days using activity monitors in boys with DMD and healthy controls (ages 5-12.9).
- Assessed functional ability and muscle strength concurrently.
- Determined ambulatory status 2 years post-baseline monitoring.
Main Results:
- Short-term activity monitoring (2-5 days) accurately predicted weekly step activity (R² = 0.80-0.95).
- Step activity significantly declined with increasing age in boys with DMD.
- Baseline step activity was strongly correlated with functional ability and strength (P < .01) and predicted 36.5% of variance.
- Boys remaining ambulatory at 2 years had nearly double the baseline step activity compared to those who ceased walking (P < .01).
Conclusions:
- Step activity in boys with DMD is closely related to and predictive of functional declines.
- Objective measurement of walking activity can serve as a valuable biomarker in DMD research.
- These findings support the utility of step activity monitoring in clinical trials for DMD to assess disease progression and treatment effects.
Introduction:
In this study we explored walking activity in a large cohort of boys with Duchenne muscular dystrophy (DMD).
Methods:
Step activity (monitored for 7 days), functional ability, and strength were quantified in ambulatory boys (5-12.9 years of age) with DMD and unaffected boys. Ambulatory status was determined 2 years later.
Results:
Two to 5 days of activity monitoring predicted weekly step activity (adjusted R2 = 0.80-0.95). Age comparisons revealed significant declines for step activity with increasing age, and relationships were found between step activity with both function and strength (P < .01). Our regression model predicted 36.5% of the variance in step activity. Those who were still ambulatory after 2 years demonstrated baseline step activity nearly double that of those who were no longer walking 2 years later (P < .01).
Discussion:
Step activity for DMD is related to and predictive of functional declines, which may be useful for clinical trials.
