Wearable Gait Technology Shows Promise in SMA and DMD

Jacqueline Montes, PT, EdD

The use of a wearable technology to assess gait function in spinal muscular atrophy (SMA) and Duchenne muscular dystrophy (DMD) demonstrated feasibility and will be further validated in a future analysis, according to a study presented at the Muscular Dystrophy Association’s (MDA) Scientific and Clinical Conference 2021, March 15-18.

Senior author Jacqueline Montes, PT, EdD, assistant professor of clinical rehabilitation and regenerative medicine, Columbia University, and colleagues tested the feasibility and validity of instrumented insoles designed at Stevens Institute of Technology for use with children and adults with SMA and DMD.

For validation purposes, gait parameters were simultaneously collected with the instrumented insoles and the gold-standard measure, the Zeno instrumented walkway, for collecting spatiotemporal parameters during data collection. All told, patients demonstrated a very good to excellent level of agreement between the insoles and gold-standard reference system.

Ten participants (3 with SMA, 3 with DMD, and 4 healthy controls [HC]) ranging from 5.2 to 46.7 years were enrolled to this point. Researchers noticed that controls generally performed better on functional tests and had greater strength compared to SMA and DMD.

"This project will result in a wearable device capable of performing ubiquitous gait analysis sensitively and accurately, thanks to novel machine learning inference models developed by the project team,” Montes et al wrote. “This will make it possible to measure subtle but meaningful changes in gait that may reflect patients’ responsiveness to treatments.”

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Patients included in the study were recorded on assessments such as 6-minute walk test, Timed Up and Go test, 10-meter walk/run, curved-line walking assessments, and handheld dynamometry of lower leg muscle groups. Stride-by-stride spatiotemporal parameters included stride length (SL), stride velocity (SV), stride time (ST), swing time (SwT), and double support (DS). Percent mean absolute error (PMAE) between the instrumented insoles and the reference system was determined for each parameter.

Preliminary data yielded an average SL in HC, DMD, and SMA of 164.25 cm, 141.36 cm, and 122.59 cm, respectively, and an average PMAE of 2.32%, 4.99%, and 2.89%, respectively. Average SV was 194.64 cm/s in HC, 163.16 cm/s in DMD, and 105.40 cm/s in SMA, corresponding to an average PMAE of 2.36%, 5.07%, and 2.86%, respectively.

Montes and colleagues found ST to be 0.842 seconds in HC, 0.882 seconds in DMD, and 1.35 seconds in SMA, with an average PMAE of 0.54%, 1.72%, and 0.74%, respectively. In HC, SwT was 0.332 seconds, whereas patients with DMD recorded 0.334 seconds and those with SMA registered 0.465 seconds. An average PMAE for SwT was 2.42%, 6.19%, and 6.39% between the 3 groups, respectively. Average DS in HC, DMD, and SMA was 0.084 seconds, 0.102 seconds, and 0.206 seconds, and average PMAE of 12.26%, 15.90%, and 11.38%, respectively.

Enrollment for the study is still ongoing. A second phase of the study will incorporate the insoles in a real-world environment to better evaluate gait during daily life activities. Following completion of enrollment, formal analysis will include validation of the instrumented insoles as well as group comparisons.

The researchers also concluded, “this novel measurement tool may permit evaluation and characterization of gait function in other neuromuscular disorders and neurological conditions where ambulatory function is compromised.”

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REFERENCE

Uher D, Duong T, Young SD, et al. Wearable technology to assess gait function in spinal muscular atrophy and Duchenne muscular dystrophy. Presented at MDA Clinical and Scientific Conference 2021; March 15–18.