How do ankle-foot orthoses affect slope and stair walking? A narrative review

BACKGROUND: The usability of ankle-foot orthoses (AFOs) during slope and stair walking is limited as these activities require different AFO properties compared with level ground walking. The development of AFOs with adaptive properties could increase their usability in daily life, but first limitations of current AFOs should be documented. OBJECTIVES: We aimed to provide an overview of (1) the biomechanical efficacy and (2) the user experiences of slope and stair walking with AFOs. STUDY DESIGN: Narrative review. METHODS: For both aims, we searched the MEDLINE database for relevant studies on July 2, 2025. We formulated a broad search strategy including keywords and MeSH terms related to "ankle-foot orthoses," "experiences," "slope," "incline," and "stairs." We included studies if they reported quantitatively on biomechanical data or qualitatively on user experience for slope, incline, or stair walking with AFOs. RESULTS: Six studies evaluated the biomechanical effects of slope and stair walking, showing that AFOs with a high stiffness significantly reduced the ankle dorsiflexion angle, leading to compensatory knee and hip flexion and less favorable outcomes. Five other studies evaluated user experiences and reported that walking on slopes and stairs with AFOs is difficult, especially stiffer ones. CONCLUSIONS: The included biomechanical studies indicate that the restriction of ankle mechanics due to the stiffness induces inefficient compensatory movement during stair and slope walking. In addition, patients report difficulties when using AFOs for these tasks. Developments in AFO design that allow for adjustments tailored to stair and slope walking may help alleviate these difficulties.