Nicholas A. LeCursi ¹ Beatrice M. Janka ¹ Fan Gao ² Michael Orendurff ³ Yufan He ⁴ Toshiki Kobayashi ^4*

• ¹ Becker Orthopedic, Troy, Michigan, United States
• ² University of Kentucky, Lexington, Kentucky, United States
• ³ Oregon Biomechanics Institute, Ashland, United States
• ⁴ Hong Kong Polytechnic University, Kowloon, Hong Kong, SAR China

Individuals with neuromuscular pathologies are often prescribed an ankle-foot orthosis (AFO) to improve their gait mechanics by decreasing pathological movements of the ankle and lower limb. AFOs can resist or assist excessive or absent muscular forces that lead to tripping, instability, and slow inefficient gait. However, selecting the appropriate AFO with mechanical characteristics that limit pathological ankle motion in certain phases of the gait cycle while facilitating effective ankle movement during other phases requires careful clinical decision-making. The aim of this study is to propose an explicit methodology for the adjustment of Multi-Function articulated AFOs in clinical settings. A secondary aim is to outline the evidence supporting this methodology and to identify gaps in the literature as potential areas for future research. An emerging class of AFO, the Multi-Function articulated AFO, offers features that permit more comprehensive, iterative, and reversible adjustments of AFO ankle alignment and resistance to ankle motion. However, no standard method exists for the application and optimization of these therapeutic devices in the clinical setting. Here we propose an evidence-guided methodology applicable to the adjustment of Multi-Function articulated AFOs in the clinical setting. Characteristic load-deflection curves are given to illustrate the idealized yet complex resistance-angle behavior of Multi-Function articulated AFOs. Research is cited to demonstrate how these mechanical characteristics can help to mitigate specific pathologic ankle and knee kinematics and kinetics. Evidence is presented to support the effects of systematic adjustment of high resistance, alignable articulated AFOs to address many typical pathomechanical patterns observed in individuals with neuromuscular disorders. Published evidence supporting most decision points of the algorithm is presented with identified gaps in the evidence. Additionally, two hypothetical case examples are given to illustrate the application of the method in optimizing Multi-Function articulated AFOs for treating specific gait pathomechanics. This method is proposed as an evidence-guided systematic approach for the adjustment of Multi-Function articulated AFOs. It utilizes observed gait deviations mapped to specific changes in AFO alignment and resistance settings as a clinical tool in orthotic treatment for individuals with complex neuromuscular gait disorders.