A Pilot Study of the Responsiveness of Wireless Motion Analysis in Facioscapulohumeral Muscular Dystrophy

INTRODUCTION: We determined whether instrumenting timed functional tasks with wireless inertial motion sensors were responsive to facioscapulohumeral muscular dystrophy (FSHD) progression and movement pattern changes. METHODS: Ten individuals who were clinically affected with genetically confirmed FSHD, mean age 54 years (range 42-65), performed an instrumented timed up and go (iTUG) trial at each visit, wearing six wireless inertial sensors. We determined the estimated average monthly slope of progression and 12-month change for temporal and spatial motion variables using a linear mixed effects model. RESULTS: For an average of 20.6 months (range 6.1-34.5), the iTUG duration stayed constant, whereas stride length, stride velocity, and trunk sagittal range of motion changed, indicating poorer performance. Arm swing changed in a compensatory direction toward the normative mean. DISCUSSION: This study provides preliminary evidence that iTUG motion variables could be sensitive to progression in FSHD, but this requires validation in a larger study.