# KNR 352: Quantitative Analysis in Biomechanics - PowerPoint PPT Presentation

KNR 352: Quantitative Analysis in Biomechanics

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KNR 352: Quantitative Analysis in Biomechanics

## KNR 352: Quantitative Analysis in Biomechanics

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##### Presentation Transcript

1. KNR 352: Quantitative Analysis in Biomechanics Dr. Steve McCaw 227B 438-3804 www.castonline.ilstu.edu/mccaw

2. Topics • Basic Operations required • Dealing with vectors • Review from 282 (Basic Biomechanics) • Kinematics • Calculations of basic quantities • Displacement, velocity, acceleration • Kinetics • Calculations • GRF, CofP, JMF • Energetics • Calculations • Power, Work

3. Performance Injury

4. Performance Injury TASK

5. Task Factors • Basic Skill • Walking • Jumping • Take off & Landing • Running • Take off & Landing • What joint actions are occurring? • What muscles are active? • What are the risks?

6. Task Factors • Basic Skill • Complex Task • Throw • Assembly Task • Curl up • Hitting a baseball • What joint actions are occurring? • What muscles are active? • What are the risks?

7. Performance Injury TASK Environment

8. Environmental Factors • Weather/field/floor conditions • Friction====>stability, tissue loads

9. Environmental Factors • Weather/field/floor conditions • Gravity • space travel & platforms

10. Environmental Factors • Weather/field/floor conditions • Gravity • Open/closed task • dynamic vs. static environment

11. Environmental Factors • Weather/field/floor conditions • Gravity • Open/closed task • Rules on the game/of the job • # of players • field dimensions • workplace layout • temporal constraints

12. Performance Injury TASK Individual Environment

13. Individual Factors • Cognitive ability

14. Individual Factors • Cognitive ability • Anthropometrics

15. Individual Factors • Cognitive ability • Anthropometrics • Psychological state

16. Individual Factors • Cognitive ability • Anthropometrics • Psychological state • Fitness & Health • Skill level

17. Performance Injury TASK Individual Environment

18. Performance Injury TASK Individual Environment

19. Performance Injury TASK Individual Environment Modulated by force: described by mechanics

20. Every structure that participates in the movement of the body does so according to physical and physiological principles. Hamilton & Luttgens, Kinesiology: Scientific basis of Human Motion, 10th edition.

21. Mechanicsinfluence of force on bodies • Biomechanics: force on biological organisms • biomechanics of fluids • circulation (lung, blood, artery)

22. Mechanicsinfluence of force on bodies • Biomechanics: force on biological organisms • biomechanics of fluids • biomechanics of deformable solids • bones, ligaments, tendons

23. Mechanicsinfluence of force on bodies • Biomechanics: force on biological organisms • biomechanics of fluids • biomechanics of deformable solids • biomechanics of rigid bodies • body as “rigid links” at “frictionless hinges”

24. Kinematics description of pattern of motion how far how fast how consistent Kinetics Mechanics

25. Kinematics description of pattern of motion how far how fast how consistent temporal aspects durations sequencing Kinetics Mechanics

26. Kinematics description of pattern of motion how far how fast how consistent temporal aspects durations sequencing Kinetics study of forces that cause motion Mechanics

27. Kinematics description of pattern of motion how far how fast how consistent temporal aspects durations sequencing Kinetics study of forces that cause motion magnitude direction line of action point of application Mechanics

28. F = m a

29. F = m a Force CAUSES acceleration

30. F = m a Force CAUSES acceleration Force CAUSES injury

31. Fundamental Concepts for Biomechanical Analysis • Units of Measure: ISU (International system of Units, ie the Metric System)

32. Fundamental Concepts for Biomechanical Analysis • Units of Measure: ISU (International system of Units, ie the Metric System) • Base Units • length: meter (m) • mass: gram (g) • time: second (s)

33. Motion • Change in position of a body with respect to time

34. Motion • Change in position of a body with respect to time • quantify POSITION • location in 3D space: P • three reference axes: X, Y, Z • Cartesian system: axes at 90o (orthogonal)

35. ISB Convention: 2D Y Progression X 0,0

36. ISB Convention: 3D Vertical Y Medio-Lateral Z Anterior-Posterior X 0,0,0

37. Scalar quantity described by magnitude alone mass volume distance speed Vector quantity requires description of magnitude and direction force momentum impulse displacement velocity acceleration Scalars and Vectors

38. Parallelogram Law forAddition of Vectors • Sum of two vectors (resultant, R) equals the diagonal of the parallelogram with sides equal to the two vectors. • Draw on board, tail to tail • Triangle Rule: tip to tail • commutative: R = A + B = B + A • Polygon Rule: extends to 3 or more vectors

39. Review: Basic Trigonometry • Right angle Triangle • naming conventions • Pythagorean Theorem • Trig functions • Sine, Cosine, Tangent (slope) • Inverse Tangent

40. Coordinate Systems • Rectangular or Cartesian Coordinate System • P = Px + Py • Polar coordinate system • P = r and Ө • Polar to rectangular • (use SOH and CAH) • Rectangular to Polar • use Pythagorean Thereom and arctan Examples: P to R: 270 N @ 23 degrees R to P: Fv= 1300 N & FA/P = 100 N

41. Adding Force (vectors) by Summing Components • Force: magnitude & direction need to be calculated

42. Adding Force (vectors) by Summing Components • Force 1 = 50 N at -45 degrees • Force 2 = 30 N at 90 degrees Solve for Resultant

43. Adding Force (vectors) by Summing Components • Force 1 = 50 N at -45 degrees • Force 2 = 30 N at 90 degrees • Force 3 = 75 N at 28 degrees • Force 4 = 15 N horizontal & 13 N vertical Solve for Resultant

44. New & Useful Information Radian – the angle created by the arc on a circle with the length of the radius of the circle (~ 57.3 degrees) Arc length = 1 radius

45. Calculate the resultant force from Coracobrachialis and Pectoralis Major Coracobrachialis = 1200 N, PM = 1700 N

46. Effect of tension development on angle of muscle insertion and muscle activation level. Given: Muscle force = 90 N /cm2 x-sectional area X-sectional area = 4 cm2 Muscle Ө relaxed = 50° Muscle Өactive = 85°Required: 150 N force along tendon Calculate: Percentage of max muscle force developed to produce the 150 N of force.

47. Additional Problems Available from web

48. Motion • Change in position of a body with respect to time • quantify POSITION • quantify TIME Motion-capture systems

49. Motion Capture • Pre 1985: Film • RedLake Locam: 500 fps • ~ \$125 roll (film + developing) • Working in the “dark” • Record • Send for processing • Hope it all turns out ok. • All black, badly focused, missed critical event • Manual Digitizing