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 and altered motor control challenge accurate measurement. Sixteen studies involving 300 participants were included. Spatial parameters gait speed, cadence, and step/stride length showed consistently good-to-excellent agreement with reference systems (ICC 0.85–0.98; 95% LoA ±0.03–0.08 m/s for gait speed, ±4–10 steps/min for cadence, and ±3–8 cm for step/stride length) and high test–retest reliability. Temporal parameters demonstrated greater heterogeneity, with larger errors and lower concordance (ICC 0.40–0.85; LoA ±0.04–0.12 s), particularly for swing time (ICC 0.40–0.70; LoA up to ±0.15 s). Paretic-side measurements showed 10–20% lower concordance and 30–50% wider limits of agreement compared with the non-paretic side, although within-subject reliability remained moderate to high. No consistent influence of sensor number on measurement accuracy was observed. Overall, wearable inertial sensors provide robust estimates of spatial gait parameters, whereas temporal outcomes especially swing time remain limited due to challenges in gait event detection under stroke-related biomechanical alterations. These findings highlight the need for standardized protocols and improved algorithms to enhance comparability across studies and support broader clinical adoption.

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.