Bio lecture intro2555


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Bio lecture intro2555

  1. 1. BasicBiomechanics for Sport Sciences Introduction Aj.Sirinart Laibsirinon Department of Physical Therapy Faculty of Allied Health Sciences 2/2554
  2. 2. Basic knowledge required prior tobiomechanics class Skeletal system: bone & joint Muscular system: muscle, tendon & ligament Anatomical position & terminology Anatomical plane & axis Joint Motion and terminology
  3. 3. A…………….….. B…………….…. D…………….…C…………………. .. . E…………….…. . F…………….…. . G…………….… .. H…………….… S…………….….. .. I…………….….. T…………….….. K……………. U…………….….. ….. L………….. N……..….. V………... W……….. X……..….. Y …………… Z …………… AA……………
  4. 4. The muscular system
  5. 5. Anatomical positionThe human body standing erect with palms turned forward, used as theposition of reference in designating the site or direction of structures of
  6. 6. Anatomicalposition
  7. 7. Anatomical Directional Terminology• Anterior : in front or in the front part• Posterior : behind, in back or rear.• Lateral : on or to the side, outside, away fromcenter• Medial : towards the middle or median• Superior : above in relation to another structure• Prone : face down• Supine : face up• Distal : situated away from centre• Proximal : situated towards centre• Dorsal : relating to back, posterior• Terms can be combined e.g. posterioinferior- behind andbelow
  8. 8. Anatomical Planes Anatomical plane
  9. 9. Frontal or Sagittal plane Transverse orcoronal plane horizontal plane
  10. 10. 1.Frontal or BCoronal APlane2. Transverseor horozontal CPlane3.SagittalPlane
  11. 11. Frontal or Sagittal PlaneCoronalPlane Transverse or horozontal Plane
  12. 12. Joint1. Neck, Lumbar or spine2. Shoulder3. Elbow4. Wrist & finger5. Hip6. Knee7. Ankle*****
  13. 13. Anatomical Planes: Joint Motion 1.Frontal or Coronal Plane: Abduction /Adduction Inversion /eversion Lateral flexion 2. Sagittal Plane: Flexion /Extension Dorsiflexion /plantarflexion 3. Horizontal Plane: Internal or medial rotation / external or lateral rotation Abduction /Adduction **** Ankle joint) Neck & Trunk
  14. 14. External Internal rotation
  15. 15. Abduction Adduction
  16. 16. Overview: BasicBiomechanics  Definition of biomechanics  Kinematics, Kinetics, Anthropometric, Kinesiol ogy  Purposes of studying biomechanics  Levers & theirs classification  Laws of motion and their influence on sport movement  Equilibrium, balance, & stability  Factors influencing balance
  17. 17. What is Biomechanics? Bio= life Mechanics= physical actions branch of physics that analyzes the actions of forces on particles and mechanical systems  Eg. Newton law: F = ma Biomechanics: ‘ Biomechanics is the science concerned with the internal and external forces acting on a human body and the effects produced by these forces’ Hay (1993) The Biomechanics of Sports Techniques. Prentice Hall Publishers
  18. 18.  Kinesiology: study of human movement
  19. 19. Sub-branch of Mechanics? Majors sub-branch of Mechanics  Statics: form of mechanics that analyzes systems in constant state of motion  Could be no movement at all  Could be constant velocity with no acceleration  Dynamics: form of mechanics that analyzes systems in motion and accelerating
  20. 20. Types of Biomechanics? Major types of Biomechanics  Kinematics: description of motion, including the pattern and speed of movement (appearance of motion)  swing  clean & jerk clean
  21. 21. Types of Biomechanics? Major types of Biomechanics  Kinetics: study of the forces associated with motion  ??? biceps 
  22. 22. Tools for biomechanical analysis
  23. 23. Anthropometric Related to the dimensions (size and shape) and weights of the body segments ????? A B C
  24. 24. ?????A BC
  25. 25. What does biomechanics have todo with anatomical kinesiology?  Anatomical kinesiology is the what  Muscle origins, insertions, and actions  Biomechanics is the how  Mechanical principles that dictate the manner those muscles work
  26. 26. Why study biomechanics Foundational understanding of mechanical principles and how they can be applied in analyzing movements of human body  What if the biomechanical principle behind variable resistance exercise machine?  Why you have to do weight lifting slowly if strength is the main focus?  What is the safest way to lift heavy weight?  At what angle should a ball be thrown fro maximum distance?
  27. 27. Purposes of studying Biomehanics Increase performance  Increase speed  Increase strength  Increase power  Improve sport skill Minimize risk of injury (primarily
  28. 28. Levers What do levers have to do with human movement?  EVERYTHING! Levers are rigid bars (in the body, bones) that move around an axis of rotation (a joint) or fulcrum Forces (supplied by muscles) cause the movement to occur
  29. 29. Lever Functions Magnify a force  A simple crowbar Increase speed and range-of-motion (ROM)  Small amount of muscular contraction proximally can produce lots of movement distally: Deltoid
  30. 30. Lever Functions Balance torques  A triple beam scale Change direction of force  A seesaw  a pulley of a weight machine
  31. 31. Lever Arm LengthDefinitions Resistance Arm: distance between axis and point of resistance application Force Arm: distance between axis and point of force Force arm Resistance arm
  32. 32. Lever Types First, second, and third class Arrangement of  the effort or muscle force,  the fulcrum or axis  the resistance determines the classification Classification determines the lever’s strengths and weaknesses
  33. 33. First Class Force or effort >> Fulcrum or Axis >>Resistance or load About 25% of the muscles in your body operate as first class levers
  34. 34. First Class
  35. 35. RF:  when axis close to resistance, produces power F: Axis R Axis  When axis close to force or effort, produces speed and ROM
  36. 36. Second Class  Axis >> Resistance>> Force or effort  Very few occurrences in the body  Gain resultant force (you can lift more), lose distance
  37. 37. Second Class
  38. 38. Second Class
  39. 39. Gastronomiesmuscle Forcecontraction force BW Resist. Axis Axis
  40. 40. Third Class Resistance >> Force or effort >>Axis or Fulcrum As much as 85% of the muscles in the body function as third class levers Usually produce speed at the expense of force Greater lever length = greater speed
  41. 41. Third Class
  42. 42. Bicep force Elbow joint Hand weight
  43. 43. 1st Class 2nd Class 3rd Class
  44. 44. Exercise 1: indicate - Axis, Muscle force, Resistance - What lever class?
  45. 45. Third class
  46. 46. Exercise 2: indicate - Axis, Muscleforce, Resistance - What lever class?
  47. 47. Force: Quadriceps Axis: Knee jointResistance Third class
  48. 48. Exercise 3: indicate - Axis, Muscleforce, Resistance - What lever class?
  49. 49. Axis: ?Muscle force: ?Resistance: ?
  50. 50. Laws of Motion Inertia Acceleration Reaction
  51. 51. Law of Inertia(Newton’s First Law) “A body in motion tends to stay in motion at the same speed in a straight line unless acted upon by a force; A body at rest tends to remain at rest unless acted upon by a force” English translation: unbalanced forces cause motion; Balanced forces don’t change anything
  52. 52. Law of Inertia (Newton’s First Law) Mass is the measure of inertia  Greater mass = greater inertia Implications for sport movement  Decreased mass USUALLY means you are easier to move (less inertia)  Agonist/antagonist reciprocal inhibition
  53. 53. Law of Acceleration (Newton’s Second Law) “The acceleration of an object is directly proportional to the force causing it, is in the same direction as the force, and is inversely proportional to the mass of the object” F = ma
  54. 54. Law of Acceleration (Newton’s Second Law) Implications for sport movement  Club/racket/bat weight  Follow through  Athlete body weight
  55. 55. Law of Reaction (Newton’s Third Law) “For every action there is an equal and opposite reaction” Ground reaction force Implications for sport movement  Artificial turf
  56. 56. Equilibrium, Balance & Stability Equilibrium is the state of zero acceleration (static or dynamic) where there is no change in the speed or direction of the body Balance is the ability to control equilibrium, either static or dynamic  center of gravity base of support  point at which all of bodys mass & weight are equally balanced or equally distributed in all directions Stability is a resistance to the disturbance of equilibrium
  57. 57. Center of gravity The whole weight of the body, or body segment (such as the forearm), acts vertically downwards through the center of gravity of the body or body segment
  58. 58. Factors Influencing Balance1. Location of the center of gravity in relation to the base of support2. Size of the base of support3. Mass of the person4. Height of the center of gravity5. Traction/friction6. Sensory perceptions
  59. 59. Aj.Sirinart