Tissue Biomechanics Flashcards
What effect do mechanical forces have on tissues?
Important for:
Development (of tissue and damage/disease)
Maintenance
Remodeling
What is the definition of tissue biomechanics?
Study of how different parts of the human body react to external forces
What is the definition of tension?
When a structure is stretched longitudinally
What is the definition of compression?
When a load produces forces that push the material together
What is the definition of shear?
Forces acting parallel to each other in opposite directions
What is the definition of torsion?
Forces twisting/rotating in opposite directions about the long axis
What is the definition of bending?
Combination of tensile and compressive loads
What kind of a force is tension?
Stretching or pulling force
What are the tension elements of the body?
Soft tissues (fascia, muscles, ligaments, and connective tissue)
When do tensile forces occur in the intervertebral disc?
During rotational movements
What part of the intervertebral disc tends to bear the tensile loads?
Annular fibers
What is the compressive force continually being transmitted to the vertebral bodies and intervertebral discs of the spine?
Gravity
How does the structure deform during a shear injury?
Internally in an angular manner
What type of bone is most at risk for a fracture?
Cancellous bone (ex. femoral condyles and tibial plateaus)
What spinal structures are able to resist shear forces?
Facet joins and fibers of the annulus fibrosus
What areas of the spine are at risk for damage by excessive rotational force (torsion)?
Facet joint
Pars interarticularis
Capsule
Annulus
What kind of long bone fracture would be an example of a torsional load failure?
Spiral fracture
Long bone fractures frequently occur through what mechanism?
Bending (combination of compression and tension)
What are the three common tissue responses to mechanical loading?
Deformation
Growth and remodeling
Failure
What is the definition of deformation?
Local shape change under the effect of applied forces
What kind of deformation occurs when an object is subjected to external forces but is in static equilibrium?
Some local shape change within the object
What four things does the extent of deformation depend on?
Material properties
Size and shape of object
Environmental factors (ex. heat or humidity)
Force
What is the difference between the measurement of a stress or strain?
Stress - measure of the intensity of the force
Strain - measure of the degree of deformation