The term "Smart Structure" is borrowed from the engineering field. Smart structures and materials are those that can adaptively respond to changes in their function with time.
An adaptive responce is one that is appropriate for the change in function. Muscles provide a good example. If you take up weight lifting, you change the function of some muscles. "Function" in the case of muscles is "producing force," and the change in the function is an increase in the total amount of force you expect the muscles to produce on a daily basis. They respond within a few weeks by becoming bulkier and stronger. In contrast, if you spend an inordinate amount of time watching television, your muscles are used much less and they athropy (decrease in size and strength) quickly. The skeleton is similarly smart, and can increase and decrease in bone mass and strength according to the forces acting on it over time. Smartness of this kind is found almost everywhere in biology.
It is easy to preturb the normal mechanical functioning of the hoof in many ways: a different trim or shoe, a new daily exercise or riding pattern, a change in feed, a pregnancy, or in cold moving the horse from barn to pasture in the spring and vica versa in the winter. In the wild, sesonal changes in ground consistancy and migration across varying terrains, domesticated horses confined in movement would achieve similar effects.
The hoof is a living "smart structure" that changes and adapts to every change that takes place in nature and every change we make in shoeing or trimming.
