Levers Flashcards

1
Q

Levers

In order for a body part to move, the appropriate bones and muscles need to work in partnership, as a series of levers.
It has 4 components:

A
  • Fulcrum/pivot – point at which the lever rotates
  • Resistance/load – force applied by the lever
  • Effort – the force applied by the user
  • Lever - bone
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2
Q

Fulcrum (definition)

Load/Resistance (definition)

Effort (definition)

A

The joint involved in the movement

The weight that is being moved e.g. dumbbell, or the body itself

Is the muscle acting as the agonist

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3
Q

First Class Lever

2 things about it?
Locations in the body?

Sporting Example with all parts named

A

“EFL”

  • Fulcrum lies between the effort and resistance/load
  • Effort Arm and Load Arm are equal = no mechanical advantage

Only 2 examples in the body:

        - Neck – moving backwards and forwards
       - Elbow during extension

Sporting Example – When throwing the javelin:

   - Effort = Tricep Brachii provides the effort to extend at the elbow
   - Fulcrum = Elbow Joint
   - Load = Javelin
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4
Q

Second Class Levers

3 things about it?
Locations in the body?

Sporting Example with all parts named

A

“ELF”

  • Load/Resistance lies between the effort and the fulcrum
  • Larger effort arm, smaller load arm = Mechanical Advantage
  • Mechanical Advantage means if can lift a relatively heavy load

Only one example in the body:

       - Ball of the foot

Sporting example – When jumping:

      - Effort = gastrocnemius
      - Fulcrum = ball of the foot
      - Load = body weight
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5
Q

Third Class Levers

4 things about it?
Locations in the body?

Sporting Example with all parts named

A

“FEL”

  • Effort is between the fulcrum and the load
  • This is the most common and, therefore, acts for all other joints in the body
  • Mechanical Disadvantage because Load arm is bigger than effort arm therefore can move a lesser load
  • Large load arm means there is a greater range of movement of speed
    E.g. knee flexion and extension

Sporting example – upward phase of bicep curl:

    - Effort = biceps brachii
     - Fulcrum = Elbow Joint
     - Load = dumbbell
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6
Q

What is MECHANICAL ADVANTAGE ?

A

SECOND CLASS
- effort arm is greater than the load arm
- large load / small effort
- slower

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7
Q

What is MECHANICAL DISADVANTAGE ?

A

THIRD CLASS
- load arm is greater than effort arm
- small load / large effort
- faster

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