1.1c - Lever systems

Why are lever important in movement?

They allow efficiency and force to be applied to the body's movements

What is a lever?

A rigid structure, a length of bone that turns around a pivot

What are the four parts to a lever?

Lever arm, pivot/fulcrum, effort, and load

What do bones act as?

lever arms

What do joints act as?

fulcrums

What do muscles provide in levers?

The effort to move loads

What are load forces often?

The weight of the body parts that are moved

What does mechanical advantage allow?

The ability to move a large output load with a smaller effort.

What are load and effort measured in?

Newtons (N)

Which levers use mechanical advantage?

First and second class levers

Mechanical advantage =

load/effort

What is an example of a first-class lever?

neck

What is an example of a first-class lever at the neck?

heading a ball in football

What is the acronym for the first-class lever?

EFL

What is an example of a second-class lever?

ankle

What is an example of a second-class lever at the ankle?

Standing on tip topes when reaching for a smash shot in badminton

What is the acronym for the second-class lever?

ELF

What is an example of a third-class lever?

elbow

What is an example of a third-class lever at the elbow?

The action of the biceps and triceps at the elbow joint when doing a bicep curl

What is the acronym for third-class levers?

FEL