Engineering Evaluation of Post-Stroke Gait Using a Wearable G-Walk Sensor Under Different Ankle-Foot Orthosis Conditions: A Longitudinal Case Study

The gait profile of post-stroke patients is typically one of reduced speed, asymmetry and decreased functional mobility. Ankle–foot orthoses (AFOs) are commonly prescribed to enhance gait stability and promote safer ambulation; however, within-person longitudinal gait changes across multiple orthotic conditions have not yet been quantitatively characterized using wearable motion analysis systems. The objective of this study was to perform a longitudinal assessment of spatiotemporal gait parameters through a wearable G-Walk inertial measurement unit (IMU) with three walking conditions: without orthosis, Conventional custom-made ankle foot orthosis AFO and Prefabricated posterior leaf spring AFO. Two functional tasks, normal walking and Timed Up and Go (TUG), were performed for each condition by a single post-stroke participant during two test sessions four months apart. Spatiotemporal key parameters such as gait speed, step length, cadence, and completion time were extracted and compared between the two time points. The gait analysis revealed trends towards increased observed gait symmetry and general functional performance with orthotics compared to walking without an AFO. Results: Longitudinal comparisons indicated that walking speed and step length in the second assessment session was higher. While the conventional custom-made AFO showed higher improvements in stability and temporal organization of gait, the PLS AFO had moderate characteristics of dynamic progression of gait. Results indicate that wearable gait analysis systems have the potential to provide objective measures of longitudinal gait adaptations and could provide useful biomechanical information for orthotic assessment and rehabilitation planning in post-stroke individuals. Further studies with larger groups of participants need to confirm these observations.