Assistive ankle-foot orthoses (AFOs) are powerful solutions to assist or
rehabilitate gait on humans. Existing assistive AFO technologies include
passive, quasi-passive, and active principles to provide assistance to the
users, and their mechanical configuration and control depend on the eventual
support they aim for within the gait pattern. In this research we analyze the
state-of-the-art of assistive AFOs and classify the different approaches into
clusters, describing their basis and working principles. Additionally, we
reviewed the purpose and experimental validation of the devices, providing the
reader with a better view of the technology readiness level. Finally, the
reviewed designs, limitations, and future steps in the field are summarized and
discussed.Comment: Figures appear at the end. Article submitted to Frontiers in
Bioengineering and Biotechnology (currently under review
