Prime Mover: A Natural History of Muscle

  • Steven Vogel
W. W. Norton: 2002. 351 pp. $25.95, £19.95
Credit: DAVID NEWTON

Steven Vogel tells us that his professional biases, as a biologist, “start with the belief that we just can't understand history, literature, economics, art, and so forth without taking biology into consideration”. Accordingly, in his book he asks what muscle physiology may reveal about human history, prehistory and culture. He is concerned with the human body, with the tools, vehicles and weapons that are powered by our muscles rather than by motors, and with the use that people make of the muscle power of animals.

To do this effectively in a book for general readers, Vogel has to use six of his 15 chapters to describe basic muscle physiology. He explains the sliding-filament mechanism of muscle contraction, the relationship between force, speed of shortening of muscle fibres and power output, and the energy cost and (in)efficiency of muscular work. He tells us about the red muscles, such as the breast meat of pigeons, that can continue working for long periods, and the white muscles of chicken breast, which are good only for short bursts of activity. We learn how the reflexes work, helping us to control movements, and how a slender muscle can exert large forces if it is built from a very large number of short muscle fibres converging on tendons.

All this is done clearly, in the readable prose that distinguishes Vogel's books, and with an attractive historical perspective. As well as being a distinguished research scientist in the field of biomechanics, Vogel is one of the best semi-popular writers on biology. He has an outstanding ability to be simple and entertaining without being misleading.

By the end of chapter 6, Vogel has got us through the basics. He has also dealt with a few of the implications of the physiology, which are the main topic of his book. For instance, we know about the extraordinary surgical operation of cardiomyoplasty, in which a dispensable shoulder muscle is wrapped around an ailing heart and stimulated to help it pump blood. And we have been shown how the elastic recoil of stretched tendons can save energy in running, or give a catapult-like boost to a jump.

Up to this point, general readers will have learned a lot but physiologists very little. The rest of the book is written at the same non-technical level, but will give almost everyone something to think about. Vogel discusses a wide variety of hand tools, using the physiology explained in the earlier chapters in conjunction with simple engineering mechanics. He discusses our use of tools ranging from pliers to corkscrews, which amplify the force that we can exert. We discover why wood is a good material for axe handles and why modern metal axe heads work better than primitive stone ones. Vogel attributes the success of eighteenth-century American colonists to their invention of axe heads that had the hole for the shaft closer to the cutting edge than in the traditional design at the time; new-style axes were less liable to be twisted by an ill-directed blow. The author tells us why crosscut saws have two kinds of tooth, and big gaps between groups of teeth. And screws, we are told, have right-handed threads because the relative strengths of different arm muscles enable a right-handed person to twist them more forcibly clockwise than anticlockwise. In some places, scientist readers may be frustrated by a lack of detail. For example, they may want a proper explanation of the sweet spot of a hammer or baseball bat, or more information about tests of human strength. However, there are plenty of footnotes and references to the literature.

Vogel regards the wheelbarrow as one of the all-time great inventions. It enables us to move heavier loads than we could carry; it has just three supports, so that it rests steadily on uneven ground; it is highly manoeuvrable; and it offers little resistance to forward movement.

Elsewhere, cycling and rowing are discussed, albeit in less detail than I would have liked, together with less-familiar man-powered vehicles, including the ancient Greek warship known as the trireme, and pedal-powered aircraft.

Vogel gives us a great deal of fascinating discussion of obsolete technology. He discusses the relative merits of horses and oxen as draft animals, and explains the design of harness and of the ingenious whippletree, which makes all the animals in a team pull with equal force. He compares medieval machines for propelling rocks into besieged cities, calculating their ranges and the time needed for reloading. He points out that it would have been best to use the heaviest possible rocks so as to get as much momentum as possible for a given energy input. And he tells us why it made ergonomic sense to cut huge blocks of stone for the pyramids but to make small mud bricks for the Great Wall of China.

Finally, Vogel considers muscle as meat. He compares the energy content of different meats, pointing out the huge differences resulting from their different fat contents. We learn why filet mignon (the psoas muscle) is particularly tender, how best to cook squid, and why (according to cannibals) human flesh tastes like pork, but sweeter.

This is a book that should be enjoyed and understood by intelligent non-scientists as much as by scientists. It offers thoughtful insight into a remarkable range of past and present human activities. Physiologists may want to skip the early chapters and may regret the lack of technical detail, but they, too, should find the book entertaining and illuminating.