JMIR Publications

ABSTRACT

Background:

Wearable robotic exoskeletons (WREs) are increasingly incorporated into neurological rehabilitation across clinical and community settings. However, the existing usability instruments were not designed to assess WRE–specific human–device interactions and therefore offer limited clinical applicability. To address this gap, the Assistive Technology Usability Questionnaire for People with Neurological Diseases (NATU Quest) was developed to evaluate usability in individuals with neurological conditions. However, its reliability and validity have been established only for assistive devices such as wheelchairs and canes, restricting its generalizability. Further evaluation is required to determine its applicability to technologically advanced WREs, including wearable robotic systems.

Objective:

This study aimed to evaluate the reliability and validity of the NATU Quest in a real-world clinical setting using a powered wearable lower-limb rehabilitation robot.

Methods:

Cross-cultural adaptation was achieved through a structured Spanish-to-Taiwanese-Chinese translation, followed by content validation using an expert panel rating (N=10). Following the adaptation process, psychometric testing of the NATU Quest was administered to 20 stroke patients following the completion of a comprehensive course of robot-assisted gait training facilitated by a WRE. The internal consistency of the NATU Quest was evaluated using the Cronbach’s α coefficient. The reliability of the test-retest procedure was evaluated using the intraclass correlation coefficient (ICC). Convergent validity was ascertained by examining the correlation between the NATU Quest scores and the System Usability Scale (SUS).

Results:

The content validity of all items in the NATU Quest demonstrated strong reliability (item-level CVI: 0.80 to 1.00; scale-level CVI: 0.93 (clarity) and 0.97 (relevance)) in the cross-cultural adaptation. Cronbach’s alpha at the second administration showed very good internal consistency (α=0.943), slightly higher than the original study of the NATU Quest. Twenty patients completed all six rehabilitation sessions, among which thirteen completed the test-retest analysis (ICC=0.823, P<.001; SEM=3.1), indicating good test-retest reliability. A robust correlation was identified between the NATU Quest and the SUS scores (Spearman ρ=0.818, P < .001), suggesting substantial convergent validity.

Conclusions:

The present study demonstrated the continued internal consistency, test-retest reliability and validity of the NATU Quest, even in the context of wearable rehabilitation robots for stroke patients. This finding suggests the potential value of the NATU Quest for a range of technologically advanced rehabilitation devices.