kin 221 - mod g1 biomechanics tissue properties

tolerance

what a tissue can withstand

exposure

the load/stress a tissue is exposed to

time dependent injuries

loads are repeated/constant causing a decrease in tolerance overtime

true

at low exposure, the risk of injury is still high

t or f

false

at low exposure, risk of injury is low

t or f

geometric properties

properties described in terms of load and deformation

false

a different load application causes different deformation with samples that have a larger CSA

material properties

properties described in terms of stress and strain

stress

normalized load (force/CSA)

pascals

stress is expressed in

strain

normalized deformation (change in length/original length)

elastic region

the area where when applying a load to a tissue, it will go back to its original state

yield point

the point of the stress-strain and load-deformation curve becomes non-linear

plastic region

area of the load-deformation and stress-strain curve where there is permanent deformation when a load is removed

ultimate failure

where the load/stress reaches it maximum value and the tissue fails

stiffness

the slope component of the load-deformation curve

young’s modulus

the slope/change in stress over strain in the stress-strain curve

true

the area under the load-deformation curve is the energy needed to cause failure

t or f

false

load deformation curve is a normalized version of the stress-strain curve

t or f

true

structural properties depends on shape and size of the tissue

t or f

bending

this loading type uses the moment of inertia

torsion

this loading type uses the polar moment of inertia

deformations

a tissue that has a longer length but the same CSA as another will withstand higher ______________

loads

a tissue that has a larger CSA but the same lengths as another will withstand higher _______

true

the black line has the stiffest tissue

t or f

false

the yellow line has the stiffest tissue

high

a material with a high young modulus will have a ____ amount of stress for a given strain

low

a material for a given stress and a high young modulus will have a ___ amount of strain

nanoindentation

bone samples with small indenter pushed into it with known forces and area of contact to measure young modulus

microindentation

a controversial method using live people have probes inserted through the skin to indent bones

standardized tension/compressive tests

destructive tests using machines to test materials with known stresses

toe region

common in ligaments/tendons and is a non-linear start of the load deformation curve

collagen

the toe region of a load deformation curve is due to __________ stretching

sample

load-deformation curves are specific to a

material

stress strain are generalizable to a ___________

false

you can use either stress strain or load deformation to see the differences in muscles with varying lengths and CSA

t or f