Longitudinal community walking activity in Duchenne muscular dystrophy

ABSTRACT

Introduction

Natural history studies for Duchenne muscular dystrophy (DMD) have not included measures of community ambulation.

Methods

Step activity (SA) monitors quantified community ambulation in 42 boys (ages 4–16 years) with DMD with serial enrollment up to 5 years by using a repeated-measures mixed model. Additionally, data were compared with 10-meter walk/run (10mWR) speed to determine validity and sensitivity.

Results

There were significant declines in average strides/day and percent strides at moderate, high and pediatric high rates as a function of age (P < 0.05). Significant correlations for 10mWR versus high and low stride rates were found at baseline (P < 0.05). SA outcomes were sensitive to change over 1 year, but the direction and parameter differed by age group (younger vs. older). Changes in strides/day and percentages of high frequency and low frequency strides correlated significantly with changes in 10mWR speed (P < 0.05).

Discussion

Community ambulation data provide valid and sensitive real-world measures that may inform clinical trials. 

Muscle Nerve, 2017