MATERIAL MECHANICS HIGH YIELD Flashcards
this is a force applied to the outside of a structure sustained by the structure
loads
what are the three types of loads?
compression
tension
shear
what is the ideal loading through bones for compression?
what does this allow?
more parallel to each other so more compression
more compression
this is applied to ligaments and starts emergency action of ligaments
tension
this type of load causes ripping or tearing
shear
can have the same stresses we’ve seen on loads:
compression, tension, shear
stress and strain
these strains allow a structure to resist strain?
elasticity
resilience
toughness
reaction to damping
strain has two types of deformation:
elasticity
plasticity
what is stress in reference to youngs modulus
refers to the amount of force per unit area of collision
what is strain in reference to youngs modulus
the amount of distortion with respect to original size/form
this law is applied to solids
not all materials are classified as solids, tissues don’t all follow the law
hooks law
this can cause material to deform in response to the load
yield point
material may fail by deforming a great deal, or more often by fracturing
failure point
bone loading consists of?
anisotropic
compression
tension
shear
this bone loading:
bones least likely to yield or fail under these load types
compression
this bone loading:
bones can fracture or fail under tension force
tension
this bone loading:
most fractures of throwing arm due to shear so hear torque develops during throwing motion
shear
this type of loading uses compression, tension and shear or any combination of these
combined loading
what is important to note about combined loading?
strains and stresses can the other to occur
the during midstance is a _____?
beam
bone adapts and alters its structure in response to stress, this applies to what law?
wolff’s law
takes effect faster than Wolff’s law because soft tissue adapts faster than the bone
davis’ law
what are the important electric currents to note?
positive and negative current
muscle contraction during midstance performs what?
stabilizing function on foot bones
what muscles stabilize the bones of the lesser tarsus during midstance?
soleus
peroneus longus
tibialis posterior
stabilization of the metatarsal bones is done by?
intrinsic muscles of the foot
stabilization is dependent on the stabilization of what?
lesser tarsus
stabilization of these rays leads to saggital plane motion occurring gin these rays (1st and 5th have own axis)
2,3,4 rays
for midstance stability, in the first half, what are the muscles?
flexor digitorum and tibialis posterior
these muscles provide transverse stability of the metatarsals and lesser tarsus
peroneus longus, tibialis posterior, and soles muscles
what stabilizes the 1st ray?
peroneus longus stabilizes the base of 1 met and plantar and lateral direction
what stabilizes the 5th ray?
not well studied
small range of motion probe limits the needs for additional muscular stabilization
what is primarily happening to STJ and rotation during tibail midstance?
acceleration of STJ supination and external rotation occurring
prime movers to start subtalar supination
tibialis posterior
soleus
long digital flexors
this muscles function accelerates external rotation of the femur
gastroc muscle
these muscles resist supination and control the rate of STJ supination during midstance
peroneus brevis and longus
this muscle prevents uncontrolled extension of the knee
gastroc muscle
