Lever Systems Flashcards
What are the components of a lever system?
-Lever (bone)
-Fulcrum (joint)
-Effort (muscular force)
-Load (weight or resistance)
-Effort arm
-Load arm
What is the acronym to remember the oder of a lever system
FLE
123
What is the first class lever?
The fulcrum is in the middle and the effort and load on on either sides
What is a second class lever?
The load in in the middle ands the fulcrum and effort are either side
What is a second class lever?
The load in in the middle ands the fulcrum and effort are either side
What is a third class lever?
The effort is in the middle and the fulcrum and load are on either sides
What is an example of a first class lever?
Extension of the neck when preparing to head a football
What is an example of a second class lever?
Ball of the foot take-off in a high jump or long jump
What is an example of a third class lever?
Flexion of the elbow during a bicep curl
Definition of effort arm
The distance from the fulcrum to the effort
Definition of load arm
The distance from the load to the fulcrum
What levers have mechanical advantage
2nd class lever
What levers have mechanical disadvantage?
3rd class
What is mechanical advantage?
The effort arm is greater than the load arm. A large load can be moved its relatively little effort. However, its efficiency is over a small range of motion and at the expense of velocity
What is mechanical disadvantage?
The load arm is greater than the effort arm. A large effort is required to move a relatively small effort But it can move a load with greater range of motion and at speed (velocity)
eg. Knee extension to kick a football
