Immediate Biomechanical Effects of Providing Adaptive Assistance With an Ankle Exoskeleton in Individuals After Stroke

• Published in: IEEE robotics and automation letters Vol. 7; no. 3; pp. 7574 - 7580
• Main Authors: de Miguel-Fernandez, Jesus, Pescatore, Camille, Mesa-Garrido, Alba, Rikhof, Cindy, Prinsen, Erik, Font-Llagunes, Josep M., Lobo-Prat, Joan
• Format: Journal Article
• Language: English
• Published: Piscataway IEEE 01.07.2022; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Ankle; Biomechanical engineering; Biomechanics; Exoskeletons; Foot; Gait; Heels; Kinematics; Legged locomotion; Prosthetics and exoskeletons; Rehabilitation; rehabilitation robotics; Robots; Stroke; Torque; Walking; wearable robotics
• ISSN: 2377-3766; 2377-3766
• DOI: 10.1109/LRA.2022.3183799

Recent studies on ankle exoskeletons have shown the feasibility of this technology for post-stroke gait rehabilitation. The main contribution of the present work is a comprehensive experimental analysis and protocol that focused on evaluating a wide range of biomechanical, usability and users' perception metrics under three different walking conditions: without exoskeleton, with an ankle exoskeleton unpowered, and with an ankle exoskeleton powered. To carry out this study, we developed the ABLE-S exoskeleton that can provide time-adapted ankle plantarflexion and dorsiflexion assistance. Tests with five participants with chronic stroke showed that walking with the ABLE-S exoskeleton significantly corrected foot drop by 25 % while reducing hip compensatory movements by 21 %. Furthermore, asymmetrical spatial gait patterns were significantly reduced by 51 % together with a significant increase in the average foot tilting angle at heel strike by 349 %. The total time to don, doff and set-up the device was of 7.86 <inline-formula><tex-math notation="LaTeX">\pm</tex-math></inline-formula> 2.90 minutes. Finally, 80 % of the participants indicated that they were satisfied with their walking performance while wearing the exoskeleton, and 60 % would use the device for community ambulation. The results of this study add to the existing body of evidence supporting that ankle exoskeletons can improve gait biomechanics for post-stroke individuals.