1. Chapter 10 Biomechanics of Physical Activity
Kathy Simpson
Chapter 10 Biomechanics of Physical Activity

2. Figure 10.1
Chapter 10 - Hoffman (2005)

3. What Is Biomechanics of Physical Activity?
Biomechanics applies the mechanical principles of physics and engineering to the motion, structure, and functioning of all living systems.
Biomechanists in the field of physical activity study how these principles affect human movement and the structure and function of the human body.

4. Goals of Biomechanics
Understand how the basic laws of physics affect and shape the structure and function of the human body.
Apply this understanding to (a) improve the outcomes of our movements (such as performance effectiveness) and (b) increase or maintain the safety and health of our tissues.

5. Motion
Force
Linear Motion
Angular Motion
General Motion

6. Levers

7. Newton’s Laws of Motion
1st Inertia: Every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force.
2nd Acceleration: The velocity of an object changes when it is subjected to an external force. The law defines a force to be equal to change in momentum (mass * velocity) per change in time.
3rd Action/Reaction: For every action (force) in nature there is an equal and opposite reaction.

8. Application of Biomechanics
Improve movement techniques for sport performance, locomotion, and motor skill acquisition.
Improve equipment.
Prevent injury.
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9. Application of Biomechanics
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10. Application of Biomechanics

11. Application of Biomechanics
Explain the difference in these shoes and how that effects a runner?

12. Application of Biomechanics (continued)
Guide rehabilitation and treatment
NOTE: Biomechanics of human movement must account for additional factors influencing movement that include sensations such as pain, other performers, the environment, emotions, prior experience, cultural expectations, socioeconomic class, gender, and anatomy.

13. Two Main Themes of Study in Biomechanics
Function: how we produce forces to generate, maintain, or slow down movement during physical activity
Structure: how forces (such as gravity) affect our body tissues

14. Biomechanical analysis

15. What Does a Biomechanist Do?
Researcher
Clinical biomechanist
Performance enhancement specialist
Ergonomist or human factors engineer (industrial task analysis specialist)
Forensic biomechanist
University professor
Certified orthotist or prosthetist

16. Goals of a Biomechanist
Improve performance in sport and dance
Reduce or prevent injuries at work, at home, and during exercise and sport tasks
Improve the movements of people with pathological conditions (clinical settings)
Increase performers’ health with exercise or training regimens
Assist with the design of equipment, artificial limbs, and orthoses for safety

17. Research Methods in Biomechanics
Model of Analysis: Systematic Process
Identify the question.
State performance goals.
Consider influencing factors.
Understand motions and mechanics.
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18. Research Methods in Biomechanics (continued)
Model of Analysis: Systematic Process
Determine relevant biomechanical principles and movement techniques.
Observe or measure.
What does it all mean? Assessment, evaluation, and interpretation.
Quantitative
Qualitative

19. Figure 10.2

20. Biomechanical Instrumentation and Other Tools
Stopwatches, metronomes, protractors, barbells, and free weights
Computer simulations
Motion measurement devices: cameras, video, light-emitting diodes (LED)
Force measurement devices: transducers, platforms, EMG

21. Assessment and Evaluation of Performers
Biomechanical profiles
Performer-related characteristics
Group of individuals
Between groups
Profiles and clinical assessment

22. Overview of Knowledge in Biomechanics of Physical Activity
How external forces (gravity, ground reaction forces, friction, fluid resistance) act on performers
How internal forces act on performers
How biomechanical laws of nature shape our movements (law of inertia, law of action–reaction, torque or moment, propulsive forces, fluid forces, and so on)

23. Biomechanists
Biomechanists as well as other physical activity specialists can apply the principles of mechanical laws to enhance performance, reduce injury, evaluate the effectiveness of a movement, or select the proper sport equipment, tool, or occupational equipment.