1. 3-1 Kinesiology for Manual Therapies Chapter 3 Basic Biomechanical Factors and Concepts McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

2. 3-2 Learning Outcomes o 3-1 Differentiate between the levers and explain how they apply to physical performance. o 3-2 Discuss how the musculoskeletal system functions as a series of simple machines. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

3. 3-3 Learning Outcomes  3-3 Describe how knowledge of torque and lever arm lengths can help improve physical performance.  3-4 Recall Newton’s laws of motion and cite examples of how the laws can apply to improving physical performance. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

4. 3-4 Learning Outcomes  3-5 Compare balance, equilbrium, and stability and discuss how they can each help improve physical performance.  3-6 Define force and momentum and describe how they can help improve physical performance.  3-7 Analyze the basic effects of mechanical loading on the tissues of the body. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

5. 3-5 Introduction  Motion cannot occur unless there is force behind it.  Motion includes many levers, torque, and pulleys that all exist as force is applied.  The study of physical action of forces is called mechanics. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

6. 3-6 Introduction (cont.)  The study of mechanics as it relates to the functional and anatomical analysis of biological systems is known as biomechanics. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

7. 3-7 Introduction (cont.)  Kinematics is concerned with the description of motion.  Kinetics is the study of forces associated with the motion of the body. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

8. 3-8 Types of Machines Found in the Body  Mechanical advantage – the ability to apply a relatively small force to move a greater resistance. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

9. 3-9 Types of Machines Found in the Body (cont.) Machines function in four ways:  To balance multiple forces  To enhance force  To enhance range of motion  To alter the resulting direction of the applied force McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

10. 3-10 Types of Machines Found in the Body (cont.) Three machines in the body produce movement:  Levers, wheels and axles, and pulleys McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

11. 3-11 Levers  A lever is defined as a rigid bar that turns around an axis of rotation.  An axis is the point of rotation around which the lever moves.  The lever rotates around the axis as a result of the force. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

12. 3-12 Levers (cont.)  Bones are the lever bars, the joints are the axes, and the muscles produce the force.  First-class lever  Second-class lever  Third-class lever McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

13. 3-13 Levers (cont.)  First-class lever is designed for balance movements. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

14. 3-14 Levers (cont.)  Second-class lever is designed to produce force movements. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

15. 3-15 Levers (cont.)  Third-class levers are designed to produce speed and range-of-motion movements.  The force is applied between the axis and the resistance. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

16. 3-16 Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

17. 3-17 Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

18. 3-18 Factors in the Use of Anatomical Levers  Torque – moment of force  Eccentric force  Force arm  Resistance arm McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

19. 3-19 Factors in the Use of Anatomical Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

20. 3-20 Factors in the Use of Anatomical Levers (cont.)  Human levers are built for speed and range of motion at the expense of force.  The longer the lever, the more effective it is in imparting velocity. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

21. 3-21 Factors in the Use of Anatomical Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

22. 3-22 Factors in the Use of Anatomical Levers (cont.)  Wheels and axles are used to enhance range of motion and speed of movement in the musculoskeletal system. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

23. 3-23 Factors in the Use of Anatomical Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

24. 3-24 Factors in the Use of Anatomical Levers (cont.)  The lateral malleolus acts as a pulley around which the tendon of the peroneus longus runs. The pulley directs the force to the plantar aspect of the foot. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

25. 3-25 Factors in the Use of Anatomical Levers (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

26. 3-26 Laws of Motion and Physical Activities  Linear motion – motion along a line  Angular motion – rotation around an axis  Displacement – change in the position or location of an object from its original point of reference McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

27. 3-27 Laws of Motion and Physical Activities (cont.)  Distance – sum length of measurement traveled  Speed – how fast an object is moving  Velocity – direction and describes rate of displacement McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

28. 3-28 Laws of Motion and Physical Activities (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

29. 3-29 Laws of Motion and Physical Activities (cont.)  Inertia – resistance to action or change  Law of inertia – a body in motion tends to remain in motion at the same speed in a straight line unless acted on by a force; a body at rest tends to remain at rest unless acted on by a force. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

30. 3-30 Laws of Motion and Physical Activities (cont.)  Acceleration – rate of change in velocity  Mass – amount of matter McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

31. 3-31 Laws of Motion and Physical Activities (cont.)  Law of acceleration - A change in the acceleration of a body occurs in the same direction as the force that caused it. The change in acceleration is directly proportional to the force causing it and inversely proportional to the mass of the body. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

32. 3-32 Laws of Motion and Physical Activities (cont.)  Law of reaction - For every action there is an opposite and equal reaction. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

33. 3-33 Laws of Motion and Physical Activities (cont.)  Sherrington’s law – is the law of reciprocal innervation. For every neural activation of a muscle, there is a corresponding inhibition of the opposing muscle. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

34. 3-34 Friction  Friction is the force that results from the resistance between the surfaces of two objects moving against one another. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

35. 3-35 Balance, Equilibrium, and Stability  Balance is the ability to control equilibrium. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

36. 3-36 Balance, Equilibrium, and Stability (cont.) Factors enhancing equilibrium, stability, and balance include:  Center of gravity falls within the base of support.  Size of the base. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

37. 3-37 Balance, Equilibrium, and Stability (cont.)  Balances depends on weight or mass.  Balance depends on the height of the center of gravity.  Balance depends on where the center of gravity is in relation to the base. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

38. 3-38 Balance, Equilibrium, and Stability (cont.)  Stability is increased by enlarging the size of the base.  Equilibrium can be enhanced by increasing friction.  Rotation around an axis aids balance. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

39. 3-39 Balance, Equilibrium, and Stability (cont.)  Kinesthetic physiologic functions contribute to balance.  Principles of balance, stability, and center of gravity can be applied to sports, preventing injuries, and achieving good body mechanics for the manual therapist. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

40. 3-40 Force  Force is the product of mass times acceleration. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

41. 3-41 Mechanical-Loading Basics  Only muscles can actively generate internal force, but tension in tendons, connective tissues, ligaments, and joint capsules may generate passive internal forces. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

42. 3-42 Mechanical-Loading Basics (cont.)  External force are produced outside the body from gravity, inertia, or direct contact. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

43. 3-43 Mechanical-Loading Basics (cont.) McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

44. 3-44 Functional Application of Throwing McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

45. 3-45 Functional Application of Throwing (cont.) Newton’s laws of motion apply in throwing:  Law of inertia  Law of acceleration  Law of reaction McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

46. 3-46 Functional Application of Throwing (cont.)  Leverage factor  Balance, equilibrium, stability McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

47. 3-47 Chapter Summary  Types of machines found in the body, levers, and factors in the use of anatomical levers provides a foundation for understanding how movement occurs from a mechanical perspective. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

48. 3-48 Chapter Summary (cont.)  The laws of motion and physical activities give fundamental explanations for movement.  Friction, balance, equilibrium and stability, force, and mechanical-loading basics are included in the topic of how the body moves. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

49. 3-49 Chapter Summary (cont.)  The example of throwing utilizes the laws of motion, leverage, and balance to perform the sport. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

50. 3-50 Chapter Review  The Chapter Review is divided into true and false, short answers, and multiple choice questions.  The questions are designed for the students to test their knowledge. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved

51. 3-51 Explore and Practice  Students should utilize the questions and charts at the end of the chapter to help focus on the content of the chapter. McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved McGraw-Hill © 2011 by The McGraw-Hill Companies, Inc. All rights reserved