Therefore bone exhibits both of these characteristics. When bone is bent it is the organic phase which allows bending. If bone is loaded slowly, it will break at a lower load than if it was loaded quickly. Therefore the bone of the Thoroughbred racehorse can stand larger loads when the loads are applied quickly. This works out well since the loads are applied more quickly when the horse is running at top speed than when the horse is just galloping.
Bones break in two entirely different manners.
The usual way people think about bone fracture is by static overload. This means that the load is increased until the bone breaks. This is the type of injury that occurs, for instance, if one fell off a ladder and broke a leg. The second method of bone failure is by fatigue failure. In this instance the bone is loaded repetitively at a load that would normally not cause fracture, but after a certain number of cycles the bone breaks anyhow.