Lecture 2 Flashcards
Creep
Gradual deformation (strain) of a tissue over time as the tissue is subjected to a constant load (stress)
Stress Relaxation
Reduction of a stress within a tissue over time as the tissue is subjected to a constant deformation (strain)
Strain
A deformation of tissue; the change of length in respect to the original length. To figure out the percent, find the difference between the original and the result and divide by the original.
Stress
Force over an area (pressure), often applied to biological tissue
Elastic Region of Stress/Strain Curve
The region in which a tissue will go back to its original length when the stress is removed.
Yield Point of Stress/Strain Curve
The point at which the Plastic Region is entered.
Plastic Region of Stress/Strain Curve
The tissue does not go back to its original length when the stress is removed. It is permanently stressed.
Modulus in Elasticity
(Change in stress)/(Change in strain)
In compression, is bone strongest, medium strength, or weakest?
Strongest
In tension, is bone strongest, medium strength, or weakest?
Medium strength
In shear force, is bone strongest, medium strength, or weakest?
Weakest
What type of exercise is the best for healthy bones?
Weight bearing exercise
Osteoporosis
Bone becomes more porous (less dense); this is seen in both men & women & especially in the elderly.
Crimp in Tendon
Bit of waviness in tendon when it is relaxed. This waviness disappears when you first start to put stress on the tendon, happens in the Toe Region of the stress/strain curve.
Are ligaments elastic?
No. Once they are stretched, they are stretched. This leaves you more prone to injuries.
