How does D3O actually work to protect my hips in a ski fall?

D3O is a rate-sensitive smart material that behaves differently depending on how quickly force is applied. During normal movement—walking, bending, skiing—the material is soft and flexible, conforming to your body like a thick gel. When you fall and hit your hip, the sudden impact causes the material's molecules to lock together almost instantly (within milliseconds), creating a rigid barrier that absorbs and disperses the impact energy. After the impact, the material returns to its soft state. Think of it like cornstarch and water: slow movements pass through easily, but sudden forces meet solid resistance.