Tissue Biomechanics Flashcards
The study of how different parts of the human body, such as bone, tendons, and muscle, react to external forces.
Tissue biomechanics
Mechanical forces play and important role in the ______, ______, and _____ of tissue as well as the development of ______ and _____.
Development
Maintenance
Remodeling
Damage and disease
Combination of tensile and compressive loads.
bending
Forces twisting/rotating in opposite directions about the long axis
torsion
Forces acting parallel to each other in opposite directions.
shear
When a structure is stretched longitudinally.
Tension/tensile
When a load produces a force that push the material together.
Compression.
Nearly constant compressive forces are applied to what area of the body?
Vertebral body and IVD
What are some compression injuries? (4)
Bruises (contusions)
Crushing injuries
Compression fractures
pinching
Stretching or pulling force of tension can also be called what?
distraction
When do tensile forces occur in the IVD?
During rotational movements
What part of the IVD tends to bear the tensile loads?
Annular fibers
What are some tension injuries?
Spain/strain
avulsion fractures
Nerve traction injuries
What bones are at most risk for fracture?
cancellous bones
What are examples of cancellous bones that are at most risk for fracture?
Femoral condyle and tibial plateaus
In the spine what RESIST shear forces?
facet joints and
Fibers of the annulus fibrosus
What are examples of shear injuries? (4)
Brain injuries
tibiofemoral translation injuries such as ACL/PCL
Blisters
Spine injuries
Excessive rotational force can result in failure of what?
Any of the elements that resist rotation.
What are some examples of things that can happen in a torsion injury? (5)
Fracture of: -Impacted facet joint -pars interarticularis Capsular tears circumferential tears of the annulus fibrosis Spiral fractures of long bones
Bending is a combination of what two types of forces?
Compression and tension
Fractures to long bones frequently occur through which mechanism?
bending
What are common tissue responses to mechanical loading/force? (3)
Deformation
growth and remodeling
failure
When acted on by external forces, objects ______ and/or _____ in the direction of the net force/torque.
Translate
rotate
Local shape change under the effect of applied force is known as what?
deformation
If an object is in static equilibrium, then it is most likely that there will be some _______ within the object.
Local shape change
The extent of deformation depends of what factors? (4)
Material properties
Size and shape of object
Environmental factors (heat/humidity)
Force (magnitude, direction , duration)
Magnitude of deformation as a result of the applied stress/loading.
Strain
Measures the intensify of the force.
stress
A measure of the degree of deformation.
strain
The amount of external force acting to deform the material.
stress
The proportional graph, what is on the side going up? What is along the bottom? Stress/strain
stress - side
Strain - bottom
Have you checked out the graphs for stress/strain in your notes?
No? Go look….
What three other qualities does the graph show?
Strength, futility, and toughness
The maximum stress a tissue can withstand without permanent deformation.
strength
Stress at the yield point of a material beyond which PERMANENT DEFORMATION will occur.
Yield strength
The maximal stress that a material can withstand prior to the initiation of failure.
Ultimate strength
The stress at which the material actually breaks or ruptures.
Failure strength
Force per unit area required to deform material, represented by the STEEPNESS (slope) of the stress/strain curve.
ductility
Tissues fail at a low stress but can withstand a large strain.
Ductile (pliant)
Tissue can withstand high stress but fail with relatively low strain.
Brittle (stiff)
