EXAM 1 REVIEW Flashcards
what type of displacement is translation + rotation?
general motion
__ __: pushes or pulls arising from outside the body
external forces
__ __: forces that act on structures of the body and arise from within the body (muscles, ligaments, bones)
internal forces
what is the most consistent and influential force encountered by the body in posture and movement?
forces of gravity
When masses of two or more segments are combined, where is the new COM vector?
the new COM vector is between & in line with the original two COM vectors
COM in anatomical position?
anterior to S2
if there is acceleration, can there be equilibrium?
no
which of Newtons laws?
An object will continue in current motion until a force causes the speed or direction to change
Law of Inertia - Newton’s 1st law
which of Newtons laws?
Acceleration of an object is directly proportional to the unbalanced forces (Funbal) or torques (Tunbal) and inversely proportional to the mass or moment of inertia
Law of acceleration - Newton’s 2nd law
___ force systems: two or more forces work on the same segment in the same line
the resultant force is the sum of the magnitudes
linear force systems
___ force systems: two or more forces work on the same segment from different angles
solve for the parallelogram using trigonometric functions
concurrent force systems
which of Newton’s laws?
for every action, there is an opposite and equal reaction
two objects touching each other result in reaction forces (reaction forces are never part of the same force system because the forces are acting on different objects)
Law of Reaction - Newton’s 3rd law
when is the magnitude of friction force always the greatest?
just before the object moves - this results in a drop of friction once the object is moving
__ ___: two forces equal in magnitude, opposite in direction, parallel and applied to the same object at different points
force couple
always produce a moment of force = torque
torque equation?
torque = (Force)(moment arm)
___ force systems: when two or more forces applied to the same object are parallel to one another
parallel force systems
___ ___: a third force is added to a force couple resulting in rotary and translator equilibrium
bending moments
a ___ is any rigid segment that rotates around a fulcrum
lever
in a lever system, __ force is greater than the ___ force to produce rotation
effort, resistance
1st class lever system?
Axis is between EF and RF
either EA or RA could be bigger
2nd class lever system?
RF is between axis and EF
EF MA is larger
3rd class lever system?
EF is between axis and RF
RF MA is larger
example of 1st class lever?
tilting head back
example of 2nd class lever?
raising heel off ground
example of 3rd class lever?
flexing elbow
In 2nd class levers, is MAd greater or less than 1?
> 1
but LESS angular displacement and velocity is gained
In 1st and 3rd class levers, is MAd great or less than 1?
< 1
but MORE angular displacement and velocity is gained
Force resolution: Fy
- perpendicular or rotary component?
- translatory or rotary?
perpendicular
rotary
Force resolution: Fx
- perpendicular or rotary component?
- translatory or rotary?
parallel
translatory
the parallel component (Fx) is ___ than the perpendicular component (Fy) for most muscles
larger
fibrous joints = ___ joints = little or no movement allowed
synarthrosis
__ joint:
- bone edges interlock one another
- frontal and parietal bones of skull early in life
suture
___ joint:
- “peg in a hole” joint
- a tooth and either mandible or maxilla
gomphosis joint
_____:
- jointed by interosseous membrane
- radius and ulna; tibia and fibula
syndesmosis
cartilagenous joints: ___: allow for some movement
amphiarthrosis
3 examples of fibrous joints?
suture joint, gomphosis joint, syndesmosis
___:
- directly joined by fibrocartilage (discs or pads) and covered with hyaline cartilage
- intervertebral joints, symphysis pubis
symphysis
___:
- connected by hyaline cartilage
- first 7 ribs to sternum
- epiphyseal growth plates near ends of long bones
synchondrosis
___ joints: no connective tissue directly unites bony surfaces
synovial
synovial joints = ___ = free to move
diarthrosis
Joint receptor type?
- stretch, usually at extremes of extension
Ruffini
joint receptor type?
- compression or changes in hydrostatic pressure and joint movement
pacini
joint receptor type?
- pressure and forceful joint motion into extremes of motion
golgi
joint receptor type?
- non-noxious and noxious mechanical stress or biomechanical stress
unmyelinated free nerve endings
____ – viscosity of fluid and essential for lubrication; synovial folds
Hyaluronate
____ – cartilage on cartilage lubrication
Lubricin
Increased swelling during injury is a result of the disruption and/or activation of nutrients and waste products. What joint receptor do you think picks up the increased pressure and signals pain?
Pacini and/or unmyelinated free nerve endings
hinge joint = ___
uniaxial
pivot joint = ___
uniaxial
condyloid joint = ___
biaxial
saddle joint = ____
biaxial
plane joint = ____
triaxial
ball and socket joint = ____
triaxial
hinge joint example?
humeroulnar
pivot joint example?
proximal radioulnar joint
condyloid joint example?
radiocarpal joint
saddle joint example?
first carpometacarpal joint
plane joint example?
intercarpal joints
ball and socket joint example?
hip joint
what position?
- full congruence of surfaces
- usually extreme ROM
- capsule and ligaments are taut
- joint is compressed
- minimal distraction is available
- no further movement
close packed
what position?
- incongruent surfaces
- usually mid-position
- ligaments and capsule laxity (least restraint to passive movement)
- distraction available
- allows for spin, roll, glide
- maximal open packed position = rest position
loose packed
soft end feel - limited by?
approximation of soft tissues
firm end feel - limited by?
capsuloligamentous stuctures
hard end feel -limited by?
bone
type I collagen resists what force?
most tension
type II collagen resists what force?
compression
type III collagen resists what force?
tension
type __ collagen makes up 90% of collagen in body
I
Interfibrillar component of extracellular matrix:
__ and ___: attract water to increase rigidity of extracellular matrix to withstand compressive forces
proteoglycans and glycosaminoglycans
___ material: display the same mechanical behavior no matter the direction of force applied
isotropic
___ material: behave differently depending on the size and direction of applied force
anisotropic
___ region: laxity in tissue straightens
toe
__ region: returns to original shape and size after being deformed
elastic
___ point: point of no return
yield
___ region: residual deformation will be permanent
plastic
___ point: tear or break
failure
stress equation?
applied force/area
___: deformation in response to an externally applied load (%)
strain
strain equation?
(final length - original length)/original length
___: resistance offered by material to external loads; inverse relationship with compliance
stiffness
___ __: measurement of structures ability to withstand changes in length
youngs modulus
ligament: toe region: ___% strain
1-2
ligament: elastic region: ___% strain
4
__: tissue deformation gradually continues if force is maintained (ex. weight on an elastic band)
creep
___-___: as tissue is stretched to a fixed length, less force is required to maintain that length overtime
stress-relaxation
___-___ ___: tissue response varies based on load speed; if load is applied rapidly, tissue is stiffer. thus larger force required to deform tissue
strain-rate sensitivity
__ __: alpha motor neuron and all muscle fibers it innervates
motor unit
type ___ muscle fiber: fast oxidative glycolytic (intermediate)
IIA
type __ muscle fiber: fast glycolytic
IIB
amount a muscle fiber can shorten or lengthen is dependent on the number of ___
sarcomeres
Neural arch of vertebra: ____
- transmit forces from posterior elements to the vertebral body
pedicles