Transcript Year 11 Biomechanics

1.2 Understanding Fitness – Introduction to Biomechanics 3
Force
 What is a force?
 A push, pull or twist that causes objects to move,
speed up, slow down, stop or change direction.
 Force = Mass x Acceleration
 Levers are used to apply a force
Levers in action:
They help us to move ourselves…
or other objects.
Downward Pressure
Resistance
Fulcrum (pivot point)
Lever arm

The distance from the fulcrum (pivot) to the point of force
(effort) is called the FORCE ARM

The distance from the fulcrum (pivot) to the point of
resistance is called the RESISTANCE ARM

In the human body, levers
are made up of the joints
(fulcrum) and the bones that
connect them to the objects
being moved.

Levers in the human body
can be manipulated to
improve speed and apply
large forces at the same
time.
Levers in Sport

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If Resistance arm is longer, lever is better for speed
and range of movement
If Resistance arm is shorter, lever is better for force
In 2nd class levers force arm is always longer,
therefore 2nd class levers are better for strength or
force
In 3rd class levers resistance arm is always longer,
therefore 3rd class levers are better for speed and
range of movement

The amount of leverage a person processes is dependent on the length
of their body, in particular the length of their arms and legs.

Longer levers result in greater speed at the end of the lever arms – this is
beneficial for throwing and striking objects.

Short levers can be moved with less force and at greater speeds – this is
beneficial for moving body parts quickly and applying strength for
pushing, pulling and lifting objects.

Question: From this information, what can you assume about a shorter
person in comparison to a taller person?
The length of the lever
• The maximum linear speed of any part of a moving lever occurs at
the point furthers from the axis.
• Amorak Advert
• Tiger Swing
The inertia of the lever
• It is more difficult to rotate a heavier and/or longer levers.
• Modified equipment
• Paralympic 100m Final
The amount of force
• The amount of force that can be applied by a muscle varies
depending on the strength of the muscle and angle of the joint.
• Longer, heavier, external levers give athletes an advantage but
performers must be able to lift them.

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The longer the lever the greater the speed.
What about control?
Which is easier to control and hit straight – an
iron or a driver?
Homework
Explain the
advantages
and
disadvantages
of teaching
badminton to
young children
by using
shorter
racquets.