Levers Flashcards
What are the 3 components of a lever?
- Fulcrum
- The joint (in most cases). - Resistance (Load)
- The object you are lifting or the body itself. - Effort
- The insertion point of the muscle which is contracting.
Classification of levers
- There are 3 classification of levers:
- 1st class levers.
- 2nd class levers.
- 3rd class levers.
*How a lever is classified depends on which one of the three components (fulcrum, resistance, effort) is in the middle.
What is the phrase to remember the levers by?
FRE-123
What are 1st class levers?
AO1= the fulcrum is in the middle.
AO2= 1st class levers can only be found during:
- extension at the elbow.
- flexion & extension in the neck (nodding).
*go back and look over diagram drawing!!
What are 2nd class levers?
AO1= the resistance is in the middle.
AO2= A 2nd class lever can only be found during:
- Plantarflexion at the ankle.
- Standing on your tip toes.
*go back and look at drawing!!!
What are 3rd class levers?
AO1= the effort is in the middle.
AO2= 3rd class levers can be found in all the joints in the body, e.g.:
- flexion at the elbow.
- extension at the knee.
Ads + Disads of 1st class levers
Advantages=
- Can produce quick movements.
- Large range of movement.
Disadvantages=
- Not able to lift heavy loads.
Ads + Disads of 2nd class levers
Advantages=
- Able to lift heavy loads.
Disadvantages=
- Not able to produce quick movements.
- Small range of movement.
Ads + Disads of 3rd class levers
Advantages=
- Can produce quick movements.
- Large range of movement.
Disadvantages=
- Not able to lift heavy loads.