“The body is a fascinating machine,” says Sandra Shefelbine, a biomechanics expert at Imperial College, London, in this 3-minute educational video by the Wellcome Trust illustrating the principles of muscle movement. “And we don’t understand most of how it works.” Indeed, when Italian scientist and mathematician Giovanni Alfonso Borelli wrote his treatise De Motu Animalium (On the Movement of Animals) in 1680, he opened up a new field of study that looked at living bodies as machines. Now recognized as the “father of biomechanics,” Borelli set out to describe a body’s motions in precise mathematical terms and illustrate the body’s musculoskeletal system as a series of simple levers, pulleys, and wheel-axles that can flex, extend, rotate, and bend. More than 3 centuries later, scientists are still trying to pick apart the nuts-and-bolts of muscle movements, including how the actions of motor and cytoskeletal proteins such as actin and myosin lead to the contraction of muscle fibers, in the hopes that such a molecular understanding of motion may lead to new therapies and treatments for muscular disorders.
(Also read “Animal Electricity, circa 1781,” which describes the discovery that electrical impulses power muscle movements.)