Concurrent Validity and Reliability of Inertial Sensor-Based Wearables for Quantifying Spatial-Temporal Gait Parameters After Stroke: A Systematic Review

This systematic review examined the validity and reliability of wearable inertial sensor systems to quantify spatiotemporal gait parameters in post‑stroke adults, a population in which gait asymmetry, altered motor control, and compensatory strategies challenge accurate measurements. Four databases were searched up to December 2025, and studies were included when they assessed concurrent validity or test–retest reliability of wearable derived spatiotemporal parameters against laboratory-based reference systems. Fifteen studies involving a total of 286 participants were analyzed. Spatial parameters as gait speed, cadence, and step and stride length showed consistent good‑to‑excellent agreement with reference instruments and high test–retest reliability. Temporal parameters demonstrated greater heterogeneity, with larger absolute errors, wider limits of agreement, and lower relative agreement, particularly for swing time. Paretic‑side measurements showed reduced between instrument agreement compared to the non‑paretic side, although within‑subject reliability remained moderate to high. No consistent influence of sensor number on measurement accuracy. Overall, wearable inertial sensors provide robust estimates of spatial gait parameters in post‑stroke populations, while temporal outcomes remain limited, likely due to the challenge to detect gait events that arise from stroke-related alterations in gait biomechanics. Taking these findings as a whole suggests that deviations from regular gait biomechanics, whether due to reduced speed particularly at low walking speeds of 0.4 m/s, asymmetry, or to the use of assistive devices, compromise the ability of wearable-based algorithms to accurately identify gait events.