HISTORY OF BIOMECHANICS

1. HISTORY OF BIOMECHANICS JENNIFER KLOTZ OLGA THEOU NICOLE WOOD CHRIS DUNCAN WON CHUNG

2. AGENDA • Antiquity 650BC – 200AD • Middle Ages 200AD – 1450AD • Italian Renaissance 1450AD – 1600AD • Scientific Revolution 1600AD – 1730AD • Enlightenment 1730AD – 1800AD • The Gait century 1800AD – 1900AD • The 20th century and beyond 1900AD - ….

3. Antiquity 650 B.C – 200 A.D Histories of sciences usually begin with the ancient Greeks Knowledge and myth were separated developing what we would call today “true scientific inquiry” Observation to develop theories

4. Pythagoras • About 580 – 500 B.C • “…..all things have form, all things are form, and all things can be defined by numbers” • His definition of the universe and the human body were based on his mathematical analysis of music • Pythagoras’ famous theorem for rectangles and triangles: a² + b² = c²

5. Aristotle • 384 – 322 B.C • “Father of Kinesiology” • Every motion presupposed a mover • The motions of falling bodies and projectiles fascinated him • Average velocity of a falling body over a given distance is proportional to the weight of the falling bodyand inversely proportional to the density of the medium • His book “About the movement of Animals” described • Movement and locomotion for the first time • The first scientific analysis of gait • The first geometrical analysis of muscular action • Explained ground reaction forces “….for just as the pusher pushes, so the pusher is pushed”

6. Archimedes • 287- 212 B.C • He claimed that he would be able to move the Earth if he only had a place to stand in order to do so • He used a close approximation for π to measure volumes and areas of solids • He established statics and hydrostatics • He determined hydrostatic principles governing floating bodies that are still accepted in swimming today • He discovered the principle of water displacement while bathing • His inquires included the laws of leverage and determining the centre of gravity and the foundation of the oretical mechanics

7. Galen • 131- 201 A.D • First “sport physician” and “team doctor” in history – “Father of Sports Medicine” • For 4 years he practiced surgery and dietetics among the gladiators, gaining substantial knowledge of the human body and human motion • “On the function of the parts” – first text on physiology • Distinguished between skeletal muscles and muscle parts, such as the heart and the stomach • Described tonus and distinguished between motor and sensory nerves, agonist and antagonist muscles • Established the science of myology • He taught that muscular contraction resulted from the passage spiritus animalius from the brain through the nerves to the muscles

8. The Middle Ages

9. When and What? • 200 B.C. – 1450 A.D. • Also known as the “Dark Ages” • Scientific development decreased • Religious and spiritual development increased • Arab scholars saved scientific investigations of antiquity from disappearing completely • The only type of knowledge desired was the knowledge of God

10. Connection to Biomechanics

11. Italian Renaissance

12. When and What? • 1450 A.D. – 1600 A.D. • The authority of the Church replaced with the authority of the ancients (Less fear of the church) • Period characterized by freedom of thought and intellectual adventure • Revival of ancient Greek philosophy, literature and art • Man became the “measure of all things”

13. Biomechanics Connection • Scientific work revived • Foundations laid for future work in anatomy and physiology • Movement and muscle actions were studied as connected entities

14. The Major Players • Leonardo da Vinci (1452-1519) • Andreas Vesalius (1514-1564)

15. Leonardo da Vinci • Self taught man • Best known as an artist but primarily served as an engineer • A very talented and imaginative man; inventions include the tank, helicopter, parachute, steam cannon, and hang glider.

16. Contributions to Biomechanics • Had the unique ability to communicate dynamic human movement in visual form

17. Contributions con’t • Mechanical analysis of movement included joints, muscles, bones, ligaments, tendons, and cartilage • Most successful illustrations included the anatomy of the arm, elbow, and hand

18. Contributions con’t • Depicted correctly the muscles (threads) by demonstrating their origin and insertion points as well as the mechanical action of the muscle dependent on its shape

19. Contributions con’t • Fused art and science by stressing perspective in his illustrations, accurately depicted ball and socket joints (hip and shoulder) as well as the correct shape of the pelvis

20. Vesalius • Education vastly contrasted da Vinci’s • Received formal training in medicine and eventually became a physician • Taught and published his anatomical theories

21. Vesalius Continued • Originally a proponent of Galen, he noticed contradictions in his work • Convinced Galen’s work was dissections of animals and wrongly portrayed the human body • Dissected executed criminals

22. Contributions to Biomechanics • In 1543 published De Humani Corporis Fabrica Libri Septem (On the Structure of the Human Body) • Boldly stated that human anatomy could only be learned from dissection and observation of the human body • Re-evaluated the anatomy of muscles (human muscles differ from animal muscles) • Stimulated scientific debate between the relationship of nerves and muscles (muscles attached to tendons and embraced nerve fibers) • His detailed descriptive anatomy laid the foundation for modern day anatomy.

26. Scientific Revolution1600-1730 • Galileo, Santorio, Harvey, Descartes, Boreli, Newton • Science was supported by private and political institutions • Intellectual freedom was highly respected • Scientists from different European countries made contact with each other • **Experimentation became the cornerstone of the new Scientific Method

27. Who is this? • “If I have been able to see further it was because I stood on the shoulders of Giants” -Newton

28. Galileo Galilei“The Wrangler”(1564-1642) • University of Pisa to study medicine • He could not accept what professors told him on faith. • University of Padua to study mathematics • He focused on experimentation • Telescope

29. Galileo & Biomechanics • Mechanical aspects of bone structure and allometry • Animals’ mass h disproportionately to their size. Therefore bones’ girth must h • Marine animals vs. terrestrial animals • Buoyancy relieves tissues of weight

30. Disproved Aristotle’s doctrine of falling bodies • Impossible that the rate of falling is a function of the object’s weight. Gravity? • Most fundamental contribution to science: • Scientific Method • Need to examine facts critically and reproduce known phenomenon experimentally so as to determine cause & effect for what is observed.

31. Galileo in Today’s Biomechanics • Aquatic PT • “water’s buoyancy relieves tissues of weight” • Provided Foundation for Newton’s 3 laws • Theory of uniform motion, projectiles, inclined plane, and he defined momentum

32. ?(1596-1650)

33. Rene Descartes’ Contributions • Cartesian Coordinate System • The Legend is that he invented this system while lying in bed observing a fly in the corner of his room

34. Contributions cont. • One of the first to use a mathematical approach to analyzing mechanics & applied it to the human body • Theory of inertia • Related the fact that motion continues in a straight line unless acted on by an external force, to the motion of planet

35. Who is this?

36. Giovanni Alfonso Borelli (1608-1679) • Began as Galileo’s student in Rome • Became Math teacher in Messina, Pisa, & Florence • Co-developer of “iatrophysical” approach to medicine • Mechanics, not chemistry, is key to understanding the functioning of the human body • Discovered forces required for equilibrium in various joints of the body before Newtown developed his laws • Determined human’s COG • Calculated inspiration and expiration volumes

37. Borelli • One of the first men to understand that the levers of the musculoskeletal system magnify motion rather than force

38. “Father of Biomechanics” • De Motu Animalium • Published after 1679 • Contents: • Used geometrical method to describe jumping, running, flying, swimming, etc. • Gait analysis & analysis of muscles • Muscle function in specific joints (knee) • Influence of muscle fibers for force production

39. Findings Hypothesized in Treatise • “Jumping” • Proposition CLXXVIII: • In jumping at an inclination to the horizon, the trajectory of the jump is parabolic • Proposition CLXXIX: • Why a jump during running is longer and higher

40. Does anyone know who this is? (1642 – 1727)

41. Isaac Newton & the “Principia” • Mathematical Principles of Natural Philosophy • Book I: • Science & mechanics • 3 Laws (Inertia, accleration, & action-reaction) • Book II: • New scientific philosophies • Descartes & Kepler • Book III: • Applications of his dynamics • Law of gravitation

42. Newton’s Laws • Law of Inertia • A body will remain at rest or continue to move at a constant velocity unless acted upon by an external force • Law of Acceleration • The acceleration of an object is directly proportional to the force causing it, it is in the same direction as the fore, and it is inversely proportional to its mass • Law of action-reaction • For every action there exists an equal and opposite reaction • Universal Gravitation • All objects attract each other with gravitational force that is inversely proportional to the square of the distance b/n the objects • This force of gravity is proportional to the mass of each of the two bodies being attracted to each other

43. Putting the Puzzle Together • Pieces of the Puzzle: • Galileo’s law of falling bodies & projectiles • Descartes’ law of inertia • Galileo failed to mention a driving force in his theory • Descartes’ theory mentioned straight lines, but the planets do not move in a straight line

44. THE AGE OF ENLIGHTENMENT(1730 AD – 1800 AD) • Period of increased understanding • Mechanical philosophers - mathematicians • Causes of motion disagreed • The concept of force more clearly understood • Advances in chemistry and a new approach to physiology

45. Born: 8 Feb 1700 in Groningen, NetherlandsDied: 17 March 1782 in Basel, Switzerland Family of mathematicians Hydrodynamica Bernoulli’s principle Daniel Bernoulli

46. A rise (fall) in pressure in a flowing fluid must always be accompanied by a decrease (increase) in the speed, and conversely, if an increase (decrease) in , the speed of the fluid results in a decrease (increase) in the pressure. Bernoulli’s principle

47. Bernoulli’s principle

48. Born: 16 October 1708 in Bern, Switzerland Died: 07 December 1777 A prodigy The founder on neurology Albrecht von Haller

49. Gait Century

50. When and What? • 1800 A.D. – 1900 A.D. • Period of time where a complementary development of mind and body was reborn (Rousseau’s novel Emile, 1762), sport and movement ideal form • Development of sport and leisure during the late 18th Century created a renewed scientific interest in human locomotion • The 19th Century was a period of development and discovery of instruments and experimental methods to increase knowledge of human movement • Gait Analysis