Tailoring Ankle-Foot Orthoses Stiffness to End-Users' Needs: Which Performance Variables Matter?

Area of Science:

• Biomechanics
• Rehabilitation Engineering
• Clinical Gait Analysis

Background:

• Ankle Foot Orthoses (AFOs) are crucial for gait assistance and rehabilitation.
• Current AFO stiffness optimization lacks standardized clinical guidelines, leading to variable user outcomes and satisfaction.
• Existing methods often fail to capture gait complexity due to limited variables and user-specific responses.

Purpose of the Study:

• To develop and evaluate a user-tailored framework for optimizing AFO stiffness.
• To identify and incorporate individual gait variables crucial for personalized AFO settings.
• To explore the impact of personalized AFO stiffness on gait performance in individuals with cerebral palsy (CP).

Main Methods:

• A pilot study involving two participants with cerebral palsy (CP).
• Analysis of key gait performance variables using machine learning models (XGBoost) and explainability techniques (SHAP values).
• Focus on identifying user-specific relationships between AFO stiffness and gait characteristics.

Main Results:

• The study identified multiple performance variables essential for capturing the complexity of gait.
• Crucially, the most relevant gait variables for AFO optimization varied significantly between the two participants.
• This demonstrates the inherent individuality in how AFO stiffness affects gait.

Conclusions:

• A personalized approach to AFO stiffness optimization is essential for improving user outcomes.
• The proposed user-tailored framework shows promise in addressing the limitations of current methods.
• Further research is warranted to validate these findings in larger, diverse populations.