The first and last images show one reason why the Greyhound is so fast,
second only to the cheetah. Greyhounds are able to run in a style that's called
"double-suspension", where there are two separate times during a single stride,
when all four legs are completely off the ground. During this period,
they are "suspended" in mid-air. The end result is that a greyhound
is rarely ever touching the ground when running at full speed. But when
those feet actually do touch the ground, they do it with incredible power!