Lever Systems

components of a lever system

fulcrum
load
effort
lever

What is the fulcrum?

a fixed pivot point
the joints

What is the load?

weight of body and anything attached to it
a body part or object

What is the effort?

force of muscle contraction required to move load
the muscles

What is the lever?

the bone

How to remember the lever systems

123, FLE

Example of 1st class lever

header in football
anything with triceps

Example of 2nd class lever

ballerina on pointe
ball of foot

Example of 3rd class lever

knee joint when crouching for tackle
anything with biceps

What is the effort arm?

distance from effort to fulcrum

What is the load arm?

distance from load to fulcrum

What is mechanical advantage?

effort arm is longer than load arm

Benefit of mechanical advantage

lift heavier loads with small effort

Disadvantage of mechanical advantage

only efficient over small range of motion

What lever always has mechanical advantage?

2nd class lever

What is mechanical disadvantage?

load arm is longer than effort arm

Benefit of mechanical disadvantage

move load at high speed
greater power over large range of motion

Disadvantage of mechanical disadvantage

lots of effort needed to move small load