Levers Flashcards
What is a lever system?
Bones and muscles work together to produce a movement
What is a lever?
The bone that rotates around a fixed point
What is a fulcrum?
The joint
What is the effort?
The muscular force created by muscles contracting and pulling on the lever, it has to be large enough to overcome the load
What is the load?
The weight or resistance
In what order in a 1st Class Lever System?
Effort, Fulcrum, Load
(EFL, English Football League)
What is an example of a 1st Class Lever System?
The extension of the neck when preparing to head a football:
- Trapezius is the effort
- The neck is the fulcrum
- The weight of the head is the load
In what order is the effort, fulcrum and load on a 2nd Class Lever System?
Fulcrum, Load, Effort
(123, FLE)
What is an example of a 2nd Class Lever System?
Standing on tiptoes while performing a releve in dance:
- Ball of foot is the fulcrum
- Body weight is the load
- Gastrocnemius and soleus is the effort
In what order is the load, fulcrum, effort in a 3rd Class Lever System?
Fulcrum, Effort Load
(She FEL over, in Barcelona!)
What is an example of a 3rd Class Lever System?
Flexion of the elbow during a bicep curl:
- Elbow joint is the fulcrum
- Biceps Brachii is the effort
- Weight of the forearm is the load
What is the ‘effort arm’?
The distance from the fulcrum to the effort
What is the ‘load arm’?
The distance from the fulcrum to the load
What effect does the ‘effort arm’ have on a lever system if it is more significant?
If it is more significant, there will be a mechanical advantage
What effect does the ‘load arm’ have on a lever system if it is more significant?
If it is more significant, there will be a mechanical disadvantage
