Biomechanics

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Biomechanics

• The Study of the Mechanics (physics) of
  Biological (living) Phenomena

Sir Issac Newton
Tiger
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Biomechanics Applications
Sport Performance Enhancement - Sport Injury
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Biomechanics Applications
Industry Ergonomics - Product Design
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Biomechanics Applications
Entertainment Animation
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Biomechanics Applications

• Medicine and Allied Health
• Physical, Occupation, Kinesio Therapy
• Orthopedics
• Prosthetics

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Biomechanics Applications

• Kinematics Description of Movement
• Kinetics Forces Associated with Movement
• Neuromuscular Muscle Function and Control of
  Movement

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BiomechanicsForce

• What is it ?
• A Push or a Pull
• Are necessary for motion to occur
• Are the result of motion
• When do we need to Increase or Decrease it?
• Forces in the Body
• Forces acting on the Body

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BiomechanicsForce

• What determines Force?
• Force ma
• m mass (amount of matter)
• a acceleration (change in velocity)
• To manipulate Force change mass and/or
  acceleration

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BiomechanicsForce

• Its a vector
• Magnitude 30 newtons
• Direction at 45 degrees

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BiomechanicsForce

• Multiple Forces can be Added Together
• The result is a unique force that reflects the
  magnitudes and directions of the forces from
  which it was created

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BiomechanicsForce

• When forces causes rotations we call them Torques
• Examples?

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BiomechanicsForce

• How do torques and forces differ?
• Forcema
• Torqueforce distance
• distance
• distance between the force and the axis of
  rotation

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BiomechanicsTorque
Torque
Axis
Force
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BiomechanicsTorque
Torques
Axis
Force
Gravity
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BiomechanicsIntroducing The Lever

• Fulcrum point around which the lever rotates
• Input Force Force exerted ON the lever
• Output Force Force exerted BY the lever

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BiomechanicsThree Classes of Levers

• First Class - fulcrum between Input and output

Second Class output between fulcrum and input
Third Class input between fulcrum and output
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BiomechanicsLevers
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Newtons Laws Of Motion
Law I - Law of Inertia A body will maintain a
state of rest or constant velocity unless acted
on by an external force that changes that state.
(Principle of Conservation of Momentum)
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Newtons Laws Of Motion

• Inertia
• the resistance of an object to motion.
• Mass
• measure of the amount of matter contained in an
  object
• Moment of Inertia
• the resistance of an object to change in angular
  motion
• dependent on the mass and the distribution of
  mass with respect to the axis of rotation

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Newtons Laws Of Motion
Law II - Law Of Acceleration The change of
motion is proportional to the force and inversely
proportional to the mass. (F ma) Law III - Law
Of Action/Reaction To every action there is
always opposed an equal reaction. (F -F)
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Biomechanics
Friction force acting parallel to the interface
of two surfaces that are in contact during the
motion or impending motion of one surface as it
moves over the other. Speed Velocity Speed
length (or distance) / change in time Velocity
(v) change in position ? position change in
time ? time v displacement d change in time
? t