Classification of Levers

Question 1

What is the definition of a lever?

Answer 1

A lever is a rigid bar or mass, which rotates around a fixed point called an axis or fulcrum, when an effort/force is applied to it.

Question 2

What is the 2 functions of a lever?

Answer 2

To gain mechanical advantage.

Speed.

Question 3

What is the definition of a first class lever?

Answer 3

Its where the effort and resistance is either side of the fulcrum.

Question 4

What is a first class lever used for?

Answer 4

Balance.
Speed.
Distance.

Question 5

Give a general and anatomical example of a first class lever?

Answer 5

General: Seesaw

Anatomical: Head acting like a seesaw with the fulcrum as the C1 vertebrae, resistance is head weight, effort/resistance is posterior muscles of neck.

Question 6

What is the definition of a second class lever?

Answer 6

Its where the fulcrum and effort are either side of the resistance.

Question 7

What is a second class lever used for?

Answer 7

To gain mechanical advantage.

Question 8

Give a general and anatomical example of a second class lever?

Answer 8

General: Wheelbarrow.

Anatomical: Metatarsal-phalangeal joint acting as a fulcrum, calf muscle is the effort and the resistance is the weight of the body.

Question 9

What is the definition of a third class lever?

Answer 9

Its where the fulcrum and resistance is either side of the effort.

Question 10

What is a third class lever used for?

Answer 10

To gain speed and distance.

Question 11

Give a general and anatomical example of a third class lever?

Answer 11

General: Bridge

Anatomical: Humero-ulnar joint acting as the fulcrum, biceps brachii acting as the effort and the resistance being the weight of the forearm exposed to gravity.