L2(L5 Makeup);C3

Question 1

What are the five types of load bearing tissues?

Answer 1

Bone 
Ligaments 
Tendons 
Cartilage 
Muscles

Question 2

These load bearing tissues adapt _____ and _____ to their loading environment

Answer 2

Positively, Negatively

Question 3

What is the definition of a load?

Answer 3

Externally applied forces and torques

Question 4

There are six different mechanical loading modes, name them

Answer 4

1. Tension
2. Compression
3. Shear
4. Torsion
5. Bending
6. Combined

Question 5

What is deformation?

Answer 5

When loaded, musculoskeletal tissues change shape

Question 6

The slope of a load deformation curve represents what?

Answer 6

Stiffness

Question 7

What is the formula for slope in a deformation curve?

Answer 7

K=change in load/ change in deformation

Question 8

What is compliance?

Answer 8

The inverse of stiffness (1/K)

Question 9

As an increased slope, stiffness _______

Answer 9

Increases

Question 10

True or false, stress and strain are a measure.

Answer 10

False, they are converted and normalized.

Question 11

What is mechanical stress?

Answer 11

When muscles develop internal resistance to loading.

Question 12

What is the formula for mechanical stress?

Answer 12

(Sigma)σ=Force/Area

Question 13

What is the difference between stress and pressure?

Answer 13

Stress is internal measure of force/cross sectional area

Pressure is external measure of force/surface area

Question 14

Stress is a ________ load

Answer 14

Normalized

Question 15

What does normalization mean?

Answer 15

Normalization is a way of allowing comparison of materials. You divide load by cross sections area.

Question 16

Stress is the ______ force over a large ________ _______

Answer 16

Same, cross-sectional area

Question 17

What is mechanical strain?

Answer 17

This is another way of measuring change in shape of material (or object) that is caused by loading.

Question 18

What’s the difference between deformation and strain?

Answer 18

Deformation is measured in absolute terms (m)

Strain is measured in relative terms (%)

Question 19

What is the formula for strain?

Answer 19

ε=(dimensions change/unloaded dimension)x100

Question 20

Strain, like stress, is __________

Answer 20

Normalized

Question 21

For the linear portion of stress and strain, slope represents the _______ ________

Answer 21

Elastic modulus (E)

Question 22

What do we convert deformation to?

Answer 22

Stress and strain curves

Question 23

What is Hookes law? Wha does it determine?

Answer 23

σ =E x ε

This determines stress and strain are linearly related

Question 24

σ =E x ε is similar to what equation?

Answer 24

Y=mx

Question 25

Recap! What are the formulas for stress, and strain?

Answer 25

Stress= force (load) divided by cross sections area Strain= deformation (change in band) divided by unloaded change multiply by 100

Question 26

Load deformation curves characterize ________ | Stress strain curves characterize ________

Answer 26

Structural properties | Material properties

Question 27

What is visoelasticity?

Answer 27

This is fluid in the muscles that change the way it shapes. It response to loading dependent on the rate of which tissues are loaded.

Question 28

MSK tissues exhibit a combination of ______ and _______ behaviour

Answer 28

Elastic, viscous

Question 29

What is elasticity?

Answer 29

When loading is removed, original shape is restored and no energy is lost.

Question 30

What are the four properties of viso-elasticity?

Answer 30

Strain rate dependency Stress relaxation Creep Hysteresis

Question 31

Describe strain rate dependency, what does viso elastic material depend on? What is this a function of?

Answer 31

the rate at which the material is being deformed will dictate how much force is produced. Viso-elastic material will depend on the speed and load. This is a function of stress and strain

Question 32

What is stress relaxation? What is this a function of?

Answer 32

This is also known as constant strain. This is a function of stress and time. Stress relaxation is when you take a tissue and hold it at constant strain. The resistance will decrease over time. Fluid distributes itself until it has a steady state. Stress will overall decrease.

Question 33

What is creep? What is it a function of?

Answer 33

This is also known as constant stress. This is a function strain and time. When you apply constant stress, strain keeps going until fluid distributes itself.

Question 34

What is hysteresis? What is it a function of?

Answer 34

This is when the loading cycle differs from unloading cycle. This is a function fo stress and strain. Energy is lost on its way back up due to viso elastic proprieties

Question 35

Explain the following terms: ``` Compression Tension Shear Stress Torsion Combined Deformation ```

Answer 35

Compression- pressing or squeezing force directly axially through a body Tension- pulling or stretching force directly through a body Shear- force directly parallel to body Stress- force/area distributed of force over body Torsion- Load producing twisting of a body around longitudinal axis Combined- more than 1 action Deformation- change in shape