Kinematics

Question 1

What does a lever consist of?

Answer 1

Fulcrum: central axis of rotation
Effort (effort arm): refers to muscle
Load (resistance arm): refers to bodyweight/dumbbell

Question 2

What are the advantages of levers & pulleys?

Answer 2

1. Increases range of motion (levers)
2. Provides speed (levers)
3. Changes direction of applied force (pulleys
4. Increases magnitude of a force - less effort to overcome load

Question 3

1st class lever

Answer 3

Counterbalance
Fulcrum in the middle

FAR

E.g. skull

Question 4

Advantage & disadvantage of 2nd class lever

Answer 4

Advantage: Can move large amounts of weight

Disadvantage: ROM very small

Question 5

Advantage & disadvantage of 3rd class lever

Answer 5

Advantage: Large ROM; Can happen vv fast

Disadvantage: Requires more force/effort = use more muscle

Question 6

2nd class lever

Answer 6

ARF

Question 7

3rd class lever

Answer 7

AFR

Question 8

Mechanical advantage of
1. First-class lever
2. Second-class lever
3. Third-class lever

Answer 8

1. MA = 1
2. MA > 1 (advantage)
3. MA < 1 (disadvantage)

Question 9

What do anatomical pulleys do?

Answer 9

Alter the direction of pull of muscle w/o changing magnitude of applied force