P.84 Gait analysis of patients with Pompe disease using a portable system

Abstract

The development of new outcome measures that can identify changes in muscle function is an unmet need for patients with neuromuscular diseases. We have used a new portable device to assess gait features of a cohort of patients with late onset Pompe disease (LOPD) and compare it with gender and age matched controls. We performed a cross-sectional study analyzing different features of gait in LOPD patients and controls. We used the new device, Ephion mobility, consisting of a set of commercial wearables interconnected within a platform that permits to register a complete cluster of biomechanical data out of the functional test performed. The connected wearables include inertial measurement units (IMU), electromyography (EMG) sensors and plantar pressure sensors embedded in shorts and insoles that allow measurement of kinematics, spatio-temporal, plantar pressure, muscle activity and cardiovascular features. Individuals wore the sensors while performing the six minute walk test (6MWT) and the 10 meter walk/run (10M). We included 18 LOPD patients (10 women) patients with a genetic diagnosis of LOPD and 27 controls. All LOPD patients were symptomatic and treated with enzyme replacement therapy. Distance walked in the 6MWT was significantly shorter for LOPD (423±103.5m) compared to controls (655±140m). We observed significant differences in the gait pattern between both groups across kinematics, spatio-temporal, plantar pressure, and EMG signals. We observed that LOPD had an increase oscillation of the trunk and pelvis during stance phase associated to a longer extension of the knee during stance and an inversion of the foot. Moreover, there are significant differences between muscle strength of the knee flexors and gluteus muscles both at rest and when walking. We observed longer co-contraction of the knee flexor and extensors while walking compared to control. There was a decrease in the ground reaction force (GRF) in the heel strike and an increase in the mid-stance resulting in a flattened GRF profile. The Ephion mobility device is an easy-to-use measurement to study different features of gait. We observed significant differences between the gait pattern of LODP patients and controls in this cross-sectional study suggesting multiple potential outcome measurements to distinguish between these two populations. Longitudinal studies are needed to identify if these measurements can capture disease progression over time.