# Feasibility and usability of a wearable sensor system for gait assessment in children with neuromuscular diseases

## TL;DR

This study shows that wearable sensors work well for assessing gait in children with neuromuscular diseases and align with traditional tests.

## Contribution

The study confirms the feasibility and usability of IMUs for gait assessment in children with NMDs.

## Key findings

- All patients completed the assessment protocol using the device, showing high feasibility.
- Good agreement was found between device-based and manual-based measurements, especially for the 6 MWT.
- SV95C showed a high correlation with the 6 MWT results.

## Abstract

In children with Neuromuscular diseases (NMDs), gait monitoring is essential for evaluating motor function over time. The 10-meter walk test (10 mWT) and the 6 Minute Walking test (6 MWT) are commonly used timed tests. Wearable inertial measurement units (IMUs) have recently gained increasing interest and use for gait assessment. The primary objective of the study is to verify the technical feasibility and clinical usability of IMUs in children with NMDs during standard 10 and 6 MWT. Secondly, the authors aimed to investigate the agreement between the results of manual and device-based tests and the device's measurements of the 95th percentile of stride speed (SV95C) and its correlation with the 6 MWT.

Ambulatory children aged 6–18 with NMDs were enrolled. The IMU used for the study was the mTest3® device. The 10 mWT and 6-MWT were performed both in the standard method and with the device. Feasibility was assessed through the completion rates of tests with the device, the thematic analysis of clinicians’ feedback, timing for the device's use and the percentage of usable recordings. Usability was evaluated using the System Usability Scale (SUS) questionnaire and a pediatric-adapted semi-structured patient interview. Agreement between the results of manual and device-based tests and the device's measurements of the 95th percentile of stride speed (SV95C) and its correlation with the 6 MWT were also evaluated.

Twelve patients with NMDs and a mean age of 12 years and 9 months (range: 8–17 years) were enrolled. All patients completed the assessment protocol using the device. Feedback from clinicians was positive, with few outlier recordings identified. Results from the SUS questionnaire and patient interview showed predominance of positive judgments. The study showed good agreement between the measurements, particularly for the 6 MWT. High correlation between SV95C and 6 MWT was also demonstrated.

This study confirmed the feasibility and usability of IMUs for gait assessment in children with NMDs. In addition, agreement between device-based and manual-based measurements and high correlation between SV95C and 6 MWT was also demonstrated. IMUs can serve both as clinical outcome assessment tools and as devices for gait monitoring across various contexts, supporting their integration into pediatric rehabilitation protocols.