History of the Study of Locomotion

The Renaissance

Leonardo da Vinci (1452-1519)

This artist, engineer, and scientist, da Vinci was particularly interested in the structure of the human body as it relates to performance, center of gravity and the balance and center of resistance. He used letter to identify muscles and nerves in the human body that he retrived from grave yards in the middle ofthe night. ( ) He described the mechanics of the body during standing, walking up and downhill, rising from a sitting position, jumping, and human gait. To demonstrate the progressive action and interaction ofvarious muscles during movement, he suggested that cords be attached to a skeleton at the points oforigin and insertion ofthe muscles.

Galileo Galilei (1564-1642)

Galileo Galilei was a student of medicine before he became famous as a physicist. He discovered the constancy of the pediod of a pendulum, and used the pendulum to measure the pulse rate of people, expressing the results quantitatively in terms of the lenght of a pendulum syncronous to the heart.

Galielo's fame was so grea and his lectures in Padua so popular that his influence on biomechanics went far beyond his personal
contribtions. According to Singer (History, p. 237), William Harvey should be regarded a disciple of Galileo. Harvey studied in
Padua (1598-1601) while Galileo was active there. By 1615 Harvey had formed the concept of circulation of blood. He published his demonstration in 1628. The essential part of his demonstration is the result not of mere observation but of the application of Galieleo's principle of measurement. He showed first thatthe blood can only leave the ventricle of the heart in one direction. Then he measured the capacity of the heart, and found it to be about two ounces. The heart beats 72 times a minute, so that in one hour it throws into the system 2x72x60 ounces =8640 ounces = 234 kg! Where can all this blood come from? Where can it all go? He concludes that the existence of circuation is a necessary condition for the function of the heart. (p.3)

Giovani Alfonso Borelli (1608-1679)

Eminent Italian mathematician and astronomer, and a friend of Galieleo. His On the Motion of Animals (De Motu Animalum) 1680 is a classic. He was succesful in clarifying muscular movement and body dynamics. He treated the flight of birds and the swimming of fish, as well as the movement of the heart and the intestines.

Borelli estimated the center of mass of nude men by having them stretch out on a rigid platform supported on a knife edge. The platform was then repositioned until is balanced, thereby indicating a location corresponding to the center of mass for the entire body.

On the Motion of Animals (De Motu Animalum) 1680

William Croone (1633-1684)

Studied the process by which signals from the brain cause a muscle contraction.

Luigi Galvani (1737-1798)

During the summer of 1786 studied the effects of atmospheric electricity on dissected frog muscles. He observed that the muscles of a frog sometimes contracted when touched by a scalpel, which led him to the conclusion that there was "in dwelling electricity which proceeded along the nerve." His Commentary on thr Effects of Electricity on Muscular Motion (1791) is probably the earliest explicit statement of the presence of electrical potentials in nerve and muscle. Galvani is considered the father of experimental neurology.

Commentary on thr Effects of Electricity on Muscular Motion (1791)