US Patent 7788826 Dynamically moderated shock attenuation system for footwear

Various embodiments of this invention disclose a dynamically responsive shock attenuation system for footwear that comprises two or more materials with different, narrowly prescribed physical properties, which, when used together, produce a dynamic, continuous, and proportional response over a wide range of impact forces. In various embodiments of the invention, the two materials comprise a first material that exhibits generally Newtonian behavior to impact forces and a second material that exhibits generally non-Newtonian behavior to impact forces.