Human biomechanics as a rigorous discipline is the relatively modern fusion of the two ancient sciences of physiology and engineering. Inquiry into biomechanics has always existed, from the earliest humans who extracted a bone from an animal carcass and successfully used it to lift a heavy stone under which tasty insect grubs burrowed. It was not until the 1970s, however, with technological advancement in electronic measurement and computation, that mechanistic principles became a prime influence in the understanding of biological systems. The human knee joint, for example, is routinely modeled as, even defined as, a mechanical hinge or lever. This approach to human anatomy extends to many varied fields beyond medicine, including athletic performance and industrial design.
It is not that the human knee hadn’t been analogized as a hinge by previous physiologists studying the structures and function of body parts. Mechanical engineering is a practical science in the language of mathematics. When it became possible to precisely measure a knee’s many parts and their tolerances to mechanical forces, it was an easy bridge to plug these numbers into known engineering equations that define the physical attributes of a hinge, or lever. Such measurements and calculations, called biometrics, are used to improve prosthetics such as artificial hip replacement joints. Human biomechanics is the attempt to define not just a bone joint but the entire human body — its structure, design and functioning — as something representable through computer simulation.
The primary purpose of biomechanics, as it applies to the human body, has been largely one of improving health. An example of this is the assessment of cardiovascular heart health through measurements of blood flow and applying them to the engineering principles governing fluid dynamics, the physical behavior of liquids. One of the more commonly known applications of human biomechanics is kinesiology, the study of movement. This has been a significant contribution to the sporting industry.
The engineering principle called optimization determines the specific values of a mechanical system, such as a motor engine, to achieve a certain state, such as efficiency or fault tolerance. With relevant measurements of a given athlete and a model of the human biomechanics of running, it is similarly possible to calculate his optimal form, stride and other values for a chance at the world record. By the same methods, it might be demonstrated that correct biomechanics for a particular baseball pitcher dictate his split-fingered fastball should be thrown with more bend, and less torque stress, at the hinged elbow joint. Technologies for measurement and analysis are what has driven the modern field of human biomechanics. Sensors such as accelerometers for measuring speed, high-speed three-dimensional motion capturing camera systems, and powerful computers capable of simulating the performance of very complex systems are all examples of the tools enabling study of the body as a mechanical system.