P.491 - Walking with weakness: a snapshot of gait in a paediatric neuromuscular clinic

Ambulant children attending a neuromuscular outpatient clinic were invited to join a prospective observational gait study. Gait was assessed barefoot at preferred and fast speed using an electronic walkway. Anthropometric and functional mobility data was collected. Speed, step length and support base (heel to heel base of support width) were normalised to height to account for the large age height range. Double support time was normalised to the gait cycle (%GC). Results were compared to normative values from a similar local cohort of typically developing children. 113 children (80 male) aged 4-17years (mean 9.6, SD 3.2) with a mean height of 1.33m (SD 0.19) and a range of diagnoses: Becker muscular dystrophy (BMD, n = 7), Duchenne muscular dystrophy (DMD, n = 38), Charcot-Marie-Tooth disease (CMT, n = 18), congenital myopathies (CM, n = 17), collagen VI myopathies (n = 12), spinal muscular atrophy (SMA, n = 7), facioscapulohumeral muscular dystrophy (FSHD, n = 5), and “other” diagnoses (myotonic dystrophy, chronic inflammatory demyelinating polyneuropathy, congenital fibre-type disproportion, axonal neuropathy, undiagnosed; n = 9) were enrolled. Mean preferred walking speed was 1.12 m/sec (SD 0.23, range 0.39–1.84). Short step length and wider support base compared to reported norms were noted in all children except those with FSHD and “other” diagnoses. Cadence was relatively preserved. Double support time was high in all groups with a mean of 19.7% (SD 3.6, range 11.1–31.2). Boys with DMD walked slowest, with shortened step length and wider support base. Asymmetry of step length was greatest in children with DMD/BMD and collagen VI myopathies. Fast gait speed was typically 150% (SD 25, range 107–217) faster than preferred speed and was achieved by increasing cadence more than step length. Only 30 (28%) children reported no limitations in their walking and 18 (17%) were part-time wheelchair users. Annual re-assessment will allow study of longitudinal change in gait performance.