GAIT ASSESSMENT WITH SOLESOUND INSTRUMENTED FOOTWEAR IN SPINAL MUSCULAR ATROPHY

Introduction: Gait impairment is common in spinal muscular atrophy (SMA) and is described using clinical assessments and instrumented walkways. Continuous over-ground walking has not been studied. Methods: Nine SMA participants completed the 6-minute walk test (6MWT) and 10-meter walk/run wearing instrumented footwear (SoleSound). Data were simultaneously collected using a reference system (GAITRite). The root-mean-square error (RMSE) indicated criterion validity. The decrease in walking speed represented fatigue. Foot loading patterns were evaluated using force sensors. Results: The RMSE for stride time, length, and velocity ranged from 1.3% to 1.7%. Fatigue was 11.6 +/- 9.1%, which corresponded to an average deceleration of 0.37 +/- 0.28 mm/s(2). Participants spent most of their stance without heel contact. Forefoot contact occurred early in the gait cycle. Conclusions: These results suggest that footwear-based devices are an alternative to specialized equipment for gait assessment. Better understanding of gait disturbances should inform ongoing treatment efforts and provide a more sensitive outcome measure.