"In today's world, machines whirl and pound and purr away, doing our bidding in return for a little petroleum, a hefty wind, or falling water. But for most of our time on earth our own muscles had to get us where we went, lift our loads, plow our fields, and reap our harvests. We were limited to muscle power - ours and that of oxen, horses, and a few other animal accomplices." "And we were limited by muscle's peculiarities. As an engine, muscle hardly varies - whether in flea or elephant or Olympic sprinter - and its limitations do not resemble anything else in the physical world. Imagine a car engine that will move you with breath-taking speed for a few seconds but that slows dramatically if asked to work for minutes and that can merely crawl along if required to work for hours. We'd think it a poor means of locomotion by modern standards. Still, that was all we had and, in many respects, most of what we have now." "In recent years, we've come to understand both the way muscle works and how hard it can work, in part by exploring how different animals use it - how flies fly and rattlesnakes rattle, how squid shoot out their tentacles and how much a hiker can carry up a mountain trail. We can see how muscle's performance rules how we do our tasks and how we design our tools - from the short handles of stone axes to the right-hand threads on most of our screws. Muscle's force and power limited, in ways we can now calculate, what we could get out of small bows and blowguns as well as slingshots and catapults. A useful thing, then, is muscle, and more, for at the end of the day it makes up most of the animal protein we eat, thereby replacing itself." "In short, the story of muscle is largely the story of humankind, and Steven Vogel, internationally hailed as a leader in the fascinating and burgeoning field of biomechanics, is its storyteller."--BOOK JACKET.