The Body in Motion – Theodore Dimon

The Body in Motion
Among the impressive array of machines which humans have invented, there is none that even remotely compares to the subtle and marvelous complexity of the human body. Our capacity for skilled movement, our upright posture, our hands, vision, and the other senses—all are marvels of engineering and design. But why do we possess this design, and how did we become this way? At first glance, many of the seemingly arbitrary details of our anatomy—the bony protrusions of the shoulder girdle, the spine, our intricate musculature—seem to defy full understanding. Yet each of these structures, when examined in terms of its functional design, proves to be uniquely suited for its particular purpose. This book will examine our anatomical design and make sense of the complex structures of the human body in the context of the specific functions they serve.
The topic of our anatomical design, as will become clear in the following pages, falls into two categories. The first deals with specific bodily systems such as the hand and shoulder girdle. Perhaps because so much of what we know about the shoulder girdle and hand is derived from dissections of the human body and detailed studies of its movement, anatomy books—even ones that specialize in movement—tend to focus on technical and quantitative descriptions of muscles, bones, and joints that are often obscure and difficult to understand. Because the subject seems inherently technical, it seems that unless we learn all these details, we’ll never really understand how the different parts of the body work.
But such technical descriptions do not do justice to the reality of how these remarkable structures actually work. In simple terms, the shoulder girdle is basically a shallow socket that supports the levers of the upper arm. Because the arms in humans have become adapted for manipulation, this socket is highly movable so that the arm can have as broad a range of motion as possible. Once we understand this, many of the features of the shoulder girdle, such as the shape of the scapula, the function of the clavicle, and the movements we can make at the shoulder, become easy to understand. The hand is also quite complex, but when we look in simple terms at how it works and how the thumb is designed to oppose the fingers, many of the details we thought were important become unnecessary, and the entire thing makes sense in a way we didn’t think possible. In this book, we’ll look at the various systems in the body and, by understanding what they do in common sense terms, make sense of their anatomical design and their specific parts.

---