Love the concept idea!

• User-Friendly Design: It’s great that you’ve labeled different materials. For ease of use, think about how the blade could attach and detach quickly. A system with adjustable straps or quick-release latches could make it easier for users to put on or remove, especially if they need to change out of it quickly.
•  Designing the blade to be detachable for storage or transport could be practical, allowing the user to easily pack it or switch out different blade designs for varied activities.
• Consider adding soft materials, like foam or gel padding, around the attachment points (where rubber is currently indicated) to enhance comfort during long usage periods. Comfort is essential for prosthetic devices, especially for active users.
• Steel and metal are excellent choices for durability, but consider lightweight options (such as carbon fiber) if the blade is intended for high-performance activities. Rubber around the attachment point is a good choice for shock absorption.
• Future versions could include sensors that monitor force or stress on the blade. These sensors could send feedback to help the user adjust their movement or alert them to any potential issues with the blade.
•  Adding small electric motors could provide powered assistance for the user, helping them control movement dynamically. This could be especially beneficial for those who may have limited control or stability.

Prototyping

• Start with materials like cardboard and foam to create a prototype. This will let you test the basic shape and function.
• Consider adding simple LEDs or visual indicators to signal if the blade is experiencing too much pressure, which could help in refining the safety aspects.
• Small servo motors could help you prototype movement control, letting you test how the blade could adjust itself or provide feedback during use.

Inspiration https://sek.nuvustudio.com/projects/114402-07-low-fidelity-prototyping-wearable-cardboard-mock-ups/tabs/134363-footwear-device