Exam 1 Flashcards
Define kinematic analysis?
no forces just describes motion
define kinetic analysis?
determines force
what is a rotary component?
perpendicular to the level at the Point of application
what does the rotary component create?
torque
which direction is the arrow going for a compressive force?
toward the joint
which direction is the arrow going for a tensile force?
away from the joint
What is newtons first law?
an object will remain at rest or in motion unless acted on
what is newtons second law?
a= F/m
what is newtons third law?
every reaction has an equal and opposite reaction
What is momentum?
quantity of motion possessed by an object
what is the equation for momentum?
P=mv
as angular velocity increases what happens to inertia?
decreases
where is the fulcrum related to EA and RA for a first class level?
in the middle
where is the fulcrum in relation to EA and RA for a second class lever?
Fulcrum–> RA–> EA
where is the fulcrum in relation to EA and RA for a third class lever?
fulcrum- EA- RA
what is the benefit of a second class lever?
favors power and is very efficient
what is the benefit of a third class lever?
favors speed and ROM but less efficient
what is the equation for mechanical advantage?
MA= EA/RA
list the levers in order of efficiency? Least to greatest
third class lever, 1st class, 2nd class
list the 4 types of descriptions for kinematic motion?
location, direction, magnitude, rate
is the agonist mover the effort arm or resistant arm?
effort arm
is the antagonist mover the effort arm or resistance arm?
resistance arm
where is the point of application in an open chain movement?
point of application is at distal attachment
where is the point of application in a closed chain movement?
point of application is at proximal attachment
do rotary forces contribute or detract from torque?
contribute
do tensile forces contribute or detract from torque?
detract
do compressive forces contribute or detract from torque?
detract
define moment arm?
perpindicular distance from line of action to axis of rotation
if the clock says 6 o clock, what is the % rotary? what is the % compression/tension
100% compression
What are the two broad categories of arthroses?
1) Synarthroses/ Synarthrodial
2) Diarthroses/ Diarthrodial
What is a Synarthroses Joint?
Connections made via fibrous or cartilaginous connective tissue
1) Fibrous
2) Cartilaginous
*more stable joints
What are examples of synarthritic fibrous joints? (3)
1) Suture -> skull
2) Gomphoses -> teeth
3)syndesmoses ->interossous membrane
What are the Sutures joint?
Sutures
- Bone united via collagenous sutural ligament or membrane
-shapes interlock or overlap
-occurs only in the skull
What are the gomphosis joints?
-Surfaces adapted like a peg in a hole
-Connected via fibrous tissue
-only found in the human body between tooth and mandible or maxilla
ex:teeth
What are the syndesmosis joint?
-Bones joined directly by an interosseous ligament or cord or aponeurotic membrane
-Small amount of motion allowed
-Ex: found between radius and ulna and tibia and fibula
What are the cartilaginous joints?
1) Symphysis Joint (secondary cartilaginous)
2) Synchondrosis joint (primary cartilaginous)
What is the Symphysis joint?
Secondary cartilaginous
- covered by thin lamina of hyaline cartilage and directly joined by fibrocartilage in the form of disks or pads
-ex: IV joint (between bodies of vertebrae)
-ex: joint between the manubrium and sternal body
ex: symphysis pubis of pelvis
What is the synchondrosis joint?
Primary cartilaginous
-hyaline (articular) cartilage joins the surfaces
-forms a bond at the ossifying enters
-permits growth, some stability and some mobility
-ex: in skull and between 1st rib and sternum (1st chondrosternal joint)
What is diarthroses?
Ends of bony components are free to move
-no connective tissue directly attaches bone
-indirectly connected by joint capsule
What is the synovial joint construction?
-joint capsule
-joint cavity
-synovial tissue lining inner capsule face
-synovial fluid
-hyaline cartilage
What are the characteristics of a joint capsule?
thin, loose, redundant, to thick and dense
mobility to stability gradation
What are the two layer in the joint capsule?
-stratum fibrosum (outer)
-Stratum synovium (inner)
What are the characteristics for Stratum fibrosum
fibrous capsule composed of DCT
type I collagen
Poorly vascularized rich in innervation
What are the characteristics for stratum synovium?
Synovial fluid production
highly vascularized and richly innervated
What’s the purpose of synovial fluid?
-Reduces friction between body surfaces
-nourishment for the AC
What is synovial fluid and where is it found?
Thin Film that covers inner later of joint capsule.
stratum synovium and AC
What does synovial fluid composed of?
Hyaluronic acid (lubricant)
Lubricin (glycoprotein)
What is Hyaluronic acid responsible for?
-viscosity of fluid and reduction of friction
What is Lubricin responsible for?
Cartilage on cartilage lubrication
resistant to bone on bone contact at rest
Which plane of movement causes the most friction?
Transverse plane movement
What is thixotropic property?
Semi solid -> fluid state
moving the toxic tissue cleans it
viscosity varies inversely with joint velocity or rate of shear
What is the example demonstrating?
With rapid joint movement, viscosity decrease = less resistance to motion
thixotropic property
with high intensity movement it creates heat in the body making the tissue more pliable and more elastic
What is the relationship between temperature and viscosity regarding the thixotropic property?
inversely related
inc temp = dec viscosity
dec temp = inc. viscosity
What the example of uniaxial diarthodial joints?
*one plane, 2 directions
-Hinge joints
-Trochoid (pivot)
-ring shaped component and other component rotates in the ring
What is an ovoid joint?
any joint with on surface convex while the other is concave
How many joints make up the elbow
3 joints
humeroulnar
humeroradial
radioulnar
What the example of biaxial diarthodial joints?
Condyloid joint (convex and concave)
saddle joint (2 convex in 1 plane concave on the other)
What the example of triaxial diarthodial joints?
Plane joint
-variety of surface configuration and permit gliding b/w 2 or more bone
ball and socket joint
-convex ball into concave socket
What is arthrokinematics?
movement of joint surfaces in relations to each other.
loss in arthrokinematics may = loss in gross osteokinematic rom
Arthrokinematics Roll
Rolling ball occurs in the direction of oseteokinematic motion
Arthrokinematics Slide/glide
Skate on ice or intervertebral facet joint motion
direction of motion dependent on joint structure
ie. joint play
Arthrokinematics Spin
Marble spinning on table/ radius on capitulum
What is the concave on convex rule?
Roll and glide are moving in the same direction
What is the convex on concave rule?
Roll and glide occur in opposite directions
prevent subluxation
ex:
What is the arthrokinematics for open chain elbow flexion?
Convex distal
Concave proximal
Roll: anterior
Glide: Anterior
What is the arthrokinematics for closed chain elbow flexion?
Convex distal
Concave proximal
Roll: anterior
Glide: posterior
What aspect of arthrokinematics is dependent on open and closed chain movement.
Glide
What aspect of arthrokinematics is not dependent on open and closed chain movement.
Roll
Where do you look for a closed chain movement to assess arthrokinematics?
Look proximal
Wolf’s law
Stimulus of the tissues responds to the load applied
What is the concavity of C1?
Superior facets concave
inferior facets convex
What is the concavity of C2?
Superior facets Convex
inferior facets convex
What is the concavity of the occipital condyles?
Convex
Requirments for summation of joint torques?
Timely addition of joint torques
Max torque produced at each joint
Definition of a moment arm?
perpindicular distance from LOA to axis of rotation
Definition of a rotary component?
pepindicular force to lever at point of application
what types of kinetic forces are external?
Gravity, friction, wind
