Levers

Question 1

What are the two functions of lever systems?

Answer 1

• Generate muscular effort to overcome a given load

- Increase speed of movement

Question 2

Name and describe the four components of a lever system

Answer 2

Lever - bone
Fulcrum - the joint/ fixed point of rotation
Effort - Muscular force
Load - weight/ resistance

Question 3

Using the example of a bicep curl in the upward phase, name each component of the lever

Answer 3

Lever - radius and ulna
Fulcrum - elbow
Effort - force created by the contraction of the bicep brachii
Load - weight of the forearm and additional weight held

Question 4

In what order does a first class lever operate?

Answer 4

L F E or E F L

Question 5

In what order does a second class lever operate?

Answer 5

F L E or E L F

Question 6

In what order does a third class lever operate?

Answer 6

F E L or L E F

Question 7

What is an advantage of a second class lever?

Answer 7

Produces considerable force over a short distance

Question 8

What is an advantage of a third class lever?

Answer 8

Accelerate a small load through a large range of motion

Question 9

Name two type one lever systems

Answer 9

Extension of the elbow and tilting the neck backwards

Question 10

Name one type two lever system

Answer 10

Plantar flexion

Question 11

Give some examples of type three lever systems

Answer 11

• Abduction, flexion and extension of the shoulder
• Flexion of the elbow
• Flexion and extension of the hip
• Flexion and extension of the knee