Biomechanics Physics of Physical Activity

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BiomechanicsPhysics of Physical Activity
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Defining Biomechanics
The study of the structure and functions of
biological systems by means of the methods of
mechanics (Hatze, 1974) Sport
Biomechanics Tissue Biomechanics Comparative
Biomechanics
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Biomechanics Issues of Interest
Performance Enhancement Injury Prevention 1
Skill Analyses (Assessment) 2 Developing New
Techniques 3 Incorporating New Equipment 4
Understanding Complex Behavior
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Evaluating the Performance of Physical Activity
1 Qualitative Involves obtaining visual or
verbal information to assess performance 2
Quantitative Involves more precise measurement of
variables that are thought to optimize or
maximize the behavior of interest
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Types of Motion
Linear Motion is caused by forces which act
through a bodys center of mass. Angular motion
is caused by forces that do not go through the
center of mass
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Types of Motion Lets not forget being stable
1 Increasing the base of support 2 Increasing
inertia 3 Decreasing the vertical distance
between the center of mass and base of
support
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Types of Motion Equilibrium
1 Static equilibrium System is at rest 2
Dynamic equilibrium System is moving with
constant velocity
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Quantitative Analyses Involves more precise
measurement of variables that are thought to
optimize or maximize the behavior of interest
Such analysis allow us to describe motion in
terms of 1 Kinematics 2 Kinetics
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Evaluation of Kinematics

• describing movements with respect to time and
  space most often using
• 1 High Speed Cinematography or
• Videography
• 2 Stroboscopy
• 3 Optoelectric
• 4 Electrogoniometry
• 5 Accelerometry

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Conducting a Kinematic Analysis
1 Setup Single or Multiple Camera
Locations 2 Calibration Camera vs. Real
Units 3 Record Data Film the Physical Activity
of Interest 4 Record Data Analyze the Data
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Kinematic Analyses
1 Time temporal characteristics of a
performance, either of the total skill or its
phases (seconds, milliseconds, etc) 2 Position
x, y, z coordinate(s) of body segment (e.g.,
CofM) 2 Displacement length and direction of
the path an athlete takes from start to finish
(inches, meters, cm, etc) 3 Velocity
displacement per unit of time (m/s) 4
Acceleration rate of change of velocity (m/s2)
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Kinematic Data Analysis Position
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Kinematic Data Analysis Velocity
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Using kinematicsPhysical Activity in space and
time
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Kinematics Remember this?
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Kinematics Gait Analysis
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Assessing Coordination
Practice