Lecture

Question 1

2nd Class Lever

Answer 1

Load in middle. Force Multiplier

Question 2

3rd Class Lever

Answer 2

Effort in middle. Distance Multiplier

Question 3

Compact/Cortical Bone

Answer 3

Outer layer. High density

Question 4

Spongy/Cancellous Bone

Answer 4

Inner layer. Loose mesh

Question 5

Bone composition

Answer 5

Inorganic portion of mineral salts (60%)
Makes bone hard and rigid
Organic matrix of collagen (30%)
Makes bones flexible and tough
Water (10%)

Question 6

Order these from strongest to weakest (Bones)
Shear, Compression, Tensile

Answer 6

1. Compression
2. Tension
3. Shear

Question 7

What is the elastic region on a stress-strain graph

Answer 7

straight line usually at the start. Bone becomes deformed but returns to its original state once unloaded

Question 8

What is the plastic region on a stress strain graph?

Answer 8

from the start of the curved region to the end of the line. It can no longer return to its original form when the load is released. As load progressively increases, it will fail

Question 9

How does cortical bone perform under stress?

Answer 9

Very good, but once it starts to deform, it will almost immediately fail

Question 10

How does cancellous bone perform under stress?

Answer 10

Deforms very easily (stress), but will continue to deform as it is difficult to break

Question 11

How does bones perform under tension?

Answer 11

The greater the angle, the quicker it fails (fails quicker when horizontal). This is due to the change of load distribution.

Question 12

a bone can withstand ______ in compression

Answer 12

190 megapascals

Question 13

a bone can withstand ______ in tension

Answer 13

130 megapascals

Question 14

a bone can withstand ______ in shear

Answer 14

70 megapascals

Question 15

Role of Fibrocartilage

Answer 15

Shock Absorption

Question 16

Role of Hyaline Cartilage

Answer 16

Reduce Friction (Nose, Ribs, End of Long Bones, Growth Plates)
End of Bone is articular cartilage

Question 17

Role of Elastic Cartilage

Answer 17

Spring back into shape (Intervertebral Discs, Pubic Symphysis)

Question 18

what type of cartilage is the acetabular labrum

Answer 18

fibrocartilage

Question 19

Role of the ligament Teres

Answer 19

stabilise hips during adduction/abduction

Question 20

ROM of hip flexion

Answer 20

120 degrees

Question 21

ROM hip abduction

Answer 21

120 degrees

Question 22

ROM hip internal/external rotation

Answer 22

20 degrees