Test 1: biomechanics

Question 1

the effects of forces acting on bodies or structures

Answer 1

mechanics

Question 2

application of mechanics in biologic
systems

Answer 2

Biomechanics

Question 3

calculated quantity of the internal interactions between adjacent
constituent elements

Answer 3

stress

Question 4

what is stress

Answer 4

a point at which forces are applied to a non homogenous surface

calculated quantity of the internal interactions between adjacent
constituent elements

Question 5

strain formula

Answer 5

Δ length/ length

measure of the deformation of a material in response to stress

Proportional difference between loaded and unloaded state

Question 6

measure of the deformation of a material in response to stress

Answer 6

strain

Question 7

“When a load is applied to a material or structure — are induced and the material is —-, therefor it deforms”

Answer 7

stresses

strained

Question 8

ultimate load a material can withstand before catastrophic failure

Answer 8

strength

Question 9

rate at which a material deforms when a load is applied

Answer 9

stiffness

Question 10

— is where there is temporary change but then return to normal

Answer 10

elastic deformation

Question 11

— is switch from elastic deformation to plastic deformation

Answer 11

yield point

Question 12

— is where there is permanent distortion without failure

Answer 12

plastic deformation

Question 13

strength depends on rate that it’s loaded

Answer 13

Viscoelastic

Stronger when loaded rapidly

Question 14

mechanical properties are dependent on direction of loading

Answer 14

Anisotropic

Stronger along long-axis

Question 15

if a load is applied rapidly bone will —

Answer 15

be stronger

Viscoelastic: strength depends on rate that it’s loaded

Question 16

Answer 16

Question 17

Answer 17

Question 18

toughness is —

Answer 18

total area under the stress strain curve

energy under the curve

Question 19

how to tell stiffness off curve?

Answer 19

slope of the elastic area = stiffness

Question 20

explain each line

Answer 20

Question 21

which has very compliant material with a very small elastic region

Answer 21

red

Question 22

which is a relatively ductile material

Answer 22

green

Question 23

relatively strong and stiff material

Answer 23

orange

Question 24

very strong and stiff material that is also very brittle and fails with very little plastic deformation

Answer 24

purple

Question 25

Answer 25

stiffness= same slope
strength= top of curve

Question 26

what bone is the most brittle

Answer 26

cortical

short plastic and deformation phase

Viscoelastic and anisotropic

Question 27

what kind of bone

Answer 27

Question 28

cancellous or cortical bone is weaker

Answer 28

cancellous

is weaker and more compliant

has short elastic phase, lower yield and lower stiffness

has very long plastic phase

Question 29

increased strain =
decreased strain =

Answer 29

new bone matrix

resorptive modeling (limb in cast gets skinnier)

wolff’s law

Question 30

wolff’s law

Answer 30

Bone forms in areas of high stress and not in areas of little stress

(limb in cast gets skinnier)

Question 31

what will form oblique fracture

Answer 31

compression/axial

Question 32

what will form transverse fracture

Answer 32

bending

Question 33

what will bending and axial force cause

Answer 33

transverse and butterfly

Question 34

torsion will cause — fracture

Answer 34

spiral

Question 35

for bone to heal strain must be

Answer 35

less then 2%

small fracture gap= higher strain (sides hit each other)

large fracture gap= lower strain

Question 36

if 100%, 10% or 2% strain body will form —

Answer 36

100= granulation tissue
10= cartilage
2= bone

Question 37

in the absence of surgery, how will the body deal with strain

Answer 37

if too much strain= fracture resorption

will form periosteal callus to decrease change in length/strain