Levers test

First class lever

Fulcrum in the middle

Second class lever

Load in the middle

Third class lever

Effort in the middle

MA > 0

1st class lever 

MA > 1 

2nd class lever

MA < 1

3rd class lever

Formula for MA

Length of effort arm/length of load arm

What amplifies force and does not amplify speed

Effort/load = MA > 1

What amplifies speed and does not amplify force 

Effort/load = MA < 1 

How is power transformed?

Power is transformed by a lever to amplify either force or speed

Where is effort exerted?

Effort (force) is where the muscle attaches 

What levers are arm extension and flexion?

1st and 3rd class levers 

Explain why more effort is required for the arm curl at position (a) compared with position (b). 

Load arms are both shortening, but position (b) is shortening more, in position (a) there is a smaller MA because there is a longer load arm

A. Explain why an athlete with shorter arms has an advantage compared with an athlete with longer arms when performing the dumbbell exercise in weightlifting.

B. Explain why an athlete with longer arms has an advantage compared with an athlete with shorter arms when throwing the discus.

A. An athlete with shorter arms means that they have a shorter load arms, that means there’s a greater MA, so less effort is required.

B. An athlete with longer arms, has a longer lever, this will increase how far the discus will go, so with this, the athlete can exert more force at the end of the lever.

When you flex your knee, where are the fulcrum and load? Where is the muscle that provides the effort located?

Fulcrum: knee joint

Load: foot and lower leg

Effort: hamstring muscles