L2 Biomechanical Principles of Trauma Flashcards
Resistance of bone to various stresors?
Bone is built to be strongest to resist compression stress:
Compression > Tension > Shear
Hierarchy of cortical bone structure?
Bone is ________ and highly ________
Bone is anisotropic and highly structured:
Orientation of load application influences the stiffness and ultimate strength
A transverse bone fracture is caused by what kind of applied force?
Tension
An Oblique fracture is caused by what kind of applied force?
Compression
A Butterfly Fracture is caused by what kind of applied force?
Bending
A Spiral fracture is caused by what kind of applied force?
Torsion
What kind of fracutes are present?
Spiral fracture of tibia
Oblique fracture of fibula
Valgus vs. Verus
Valgus: Force towards midline
Varus: Force away from midline
What is Wolff’s Law?
Significance of Ward’s Triangle?
__________ help sculpt bony apophyses
Example?
Tensile forces help sculpt bony apophyses
Tibial tuberosity
______________ is the resistance to bending moment
Anatomical Example?
2nd Moment of Inertia is the resistance to bending moment
______________ increases the area moment of inertia of a bone. It has a greater effect on resistance to bending than _______________
Periosteal bony callus increases the area moment of inertia of a bone. It has a greater effect on resistance to bending than endosteal callus
Classes of levers in the body?
What class is the deltoid musle?
Zone 1 of Articular Cartilage deals with what kind of stress?
Shear Stress
Zone 3 of Articular Cartilage deals with what kind of stress?
Compressive stress
_________ distinguishes the deep zone from calcified cartilage
Collagen fibrils are __________ to surface in deep zone
Tide mark distinguishes the deep zone from calcified cartilage
Collagen fibrils are perpendicular to surface in deep zone
Cartilage is stiffer and stronger in tension along ____________
Cartilage is stiffer and stronger in tension along split lines
_______________ and ______________ are commoner than mid tendon rupture.
Musculotendinous Rupture and Bone avulsion are commoner than mid tendon rupture.
Tendons can withstand more tensile stress than muscle or bone.
_______________ = slope of Stress/Strain plot
Stiffness
___________= Area under curve of Stress/Strain plot (StressxStrain)
Toughness: the ability of a material to absorb energy (Joules per unit volume) without fracturing
What is Young’s Modulus?
