quiz #1 - intro Flashcards
arthrology
study of joints
joint (articulation/ arthrosis)
point of contact between two bones, between bones & cartilage, between bones & teeth
kinesiology
study of motion in human body
arthrokinematics
movements that occur inside joint (roll, slide, spin)
osteokinematics
movement of body parts (flexion, extension, adduction)
collagen fibers
main component of CT, mostly found in fibrous tissues like cartilage, tendons, ligaments & skin
cartilage
flexible rubbery tissue made up of collagen & chondrocytes
articular cartilage
smooth white tissue that covers ends of bones where they form joints
articular capsule
CT surrounding joint
ligaments
bundles of collagen in parallel strips that connect one bone to another bone
joint - articulations definition
point of contact between two bones, between bones & cartilage, between bones & teeth
-their surfaces allow for varying degrees of movement
-joints of skeletal system hold bones together & allow for movement & flexibility
joint articulations - classifications (3)
- structure (how they look)
- function (how much movement occurs)
- biomechanical properties (how they move)
structural joints
fibrous
cartilaginous
synovial
functional joints
synarthrosis: immovable
amphiarthrosis: slightly moveable
diarthrosis: freely moveable (all synovial joints)
biomechanical properties
simple: two articulating surfaces (GH)
complex: two or more articulating surfaces with an articular disc / meniscus (knee/TMJ)
compound: three or more articulating surfaces (radiocarpal)
fibrous joints & types
no joint cavity
articulating bones held close together by dense, irregular CT with lots of collagen fibers
-sutures
-syndesmosis
-interosseous membrane
fibrous joints - sutures
between bones of skull
irregular interlocking edges composed of thin layer of dense irregular CT
act as shock absorber in skull
immovable/ synarthosis (slightly movable in infants)
fibrous joints - synostosis
type of suture joint that is replaced by bone as an adult -> complete fusion of two separate bones
synarthrosis, immovable because they have ossified (ex. frontal bone)
fibrous joints - syndesmosis
band / ligament, made of dense irregular CT arranged in a bundle
two joints surfaces are further away from each other
amphiarthrosis (ex. distal tibiofibular, teeth)
fibrous joints - interosseous membrane
substantial sheet of dense irregular CT
binds neighbouring bones & permits small amount of movement
amphiarthrosis (ex. between radius & ulna, tibia & fibula)
cartilaginous joints & types
no synovial cavity
little to no movement
articular bones tightly connected by hyaline / fibrocartilage
-synchondrosis
-symphysis
-epiphyseal cartilage
cartilaginous joints - synchondrosis
connecting material = hyaline cartilage
amphiarthrosis to synarthrosis
ossifies in adulthood & becomes synostosis
(ex. first rib & manubrium of sternum)
cartilaginous joints - symphysis
connecting tissue = hyaline cartilage; also has broad, flat fibrocartilaginous disc that connects bones
ALL occur in midline of body
amphiarthrosis
(ex. intervertebral joints, pubic symphysis)
cartilaginous joints - epiphyseal cartilage
not a joint but a growth within bone
covered with hyaline cartilage
not about movement but about growth
synarthrosis
*once bone elongation growth has stopped after puberty, epiphyseal plate closes & joint becomes synostosis joint
synovial joints
fluid filled cavity = synovial cavity between articulating bones
fluid = synovial fluid
cavity covered by capsule; capsule made of dense irregular CT
bones at ends of joints are covered by layer of hyaline cartilage that is smooth & slippery called articular cartilage
allows for lots of movement = diarthrosis
articular cartilage function
reduces friction between bones & absorbs shock
articular capsule
covers entire synovial joint & encloses synovial cavity while uniting articular bones
separates inside of joint from outside, has TWO membranes:
-fibrous (outside)
-synovial (inside)
articular capsule: fibrous membrane (outside)
dense irregular CT
mostly collagen
connects periosteum of articulating bones
articular capsule: synovial membrane (inside)
areolar CT with elastic fibers
synoviocytes produce synovial fluid that contains hyaluronic acid
synovial fluid functions
lubricates synovial cavity
reduces friction
shock absorbers
supplies oxygen & nutrients
takes away wastes like carbon dioxide
contains phagocytes to remove normal debris (or microbes from wear & tear)
synovial fluid: if joint is inactive…
synovial fluid becomes thicker & less viscous = main reason to warm up before activity
stimulates production & secretion of more synovial fluid = less stress on joints
accessory ligaments
extracapsular: outside capsule
intracapsular: inside capsule
articular disc
occur inside some synovial joints
crescent shaped pad of fibrocartilage that lies between articulating bones -> called meniscus (knee) / articular discs
function of articular disc
-act as shock absorbers
-make a better fit between articulating bones
-distribute weight & synovial fluid over greater surface area
-disc binds strongly to inside of fibrous membrane & often subdivides synovial cavity into two separate spaces, allowing separate movements (TMJ)
labrum
fibrocartilaginous lip that extends from edge of joint socket
helps deepen socket & increases surface area of contact between ball & socket
occurs in ball & socket joints of hip & shoulder
tendon sheaths
covering over tendon that reduces friction at joints
tube-like bursa that wraps around some tendons especially around wrists & ankles
contains small amount of synovial fluid
reduces friction in common back & forth repetitive activites
tendon sheaths - transverse humeral ligament
holds biceps tendon
has tendon sheath around it for protection & friction reduction
bursa
fluid filled sac lined with synovial membrane
acts as cushion / protection around joint by reducing friction
between skin & bones, tendon & bones, muscles & bones, ligaments & bones (where rubbing/ friction occurs)
bursitis: inflammation of bursa around joint
6 types of synovial joints
plane (planar)
hinge (ginglymus)
pivot (trochoid)
condyloid (ellipsoid)
saddle (sellar)
ball & socket (spheroid)
PLANE joints
flat/ slightly curved surfaces
permit back & forth / gliding movements
articular capsule around joints limits movement
BIAXIAL or TRIAXIAL
(ex. acromioclavicular & sternoclavicular)
HINGE joints
convex surface of one bone articulating into concave surface of another bone
permits one type of movement in one plane: flexion & extension
UNIAXIAL
(ex. elbow, knee)
PIVOT joints
articulating surface is rounded / pointed surface of one bone articulating with ring formed by another bone
allows for rotation only
UNIXIAL
(ex. atlantoaxial joint, radioulnar joint)
CONDYLOID joints
convex oval shaped projection of one bone fits into oval shaped depression of another bone
two degrees of motion (flex, ext, ADD, ABD, circ)
BIAXIAL
(ex. radiocarpal joint)
SADDLE joints
articular surface of one bone is saddle shaped, other surface fits in saddle
two planes of motion (flex, ext, ADD, ABD, circ)
BIAXIAL
(ex. carpometacarpal joint (trapezium and the thumb))
BALL & SOCKET joints
ball shaped surface of one bone fitting into cuplike depression of another bone
movement in many directions (rotation)
TRIAXIAL / MULTIAXIAL
(ex. GH, hip)
factors affecting contact in synovial joints
- structure/ shape of articulating bones, how closely they fit together
- strength, tension, tautness of ligaments around joint, restrict ROM
- arrangement & tension of muscles
- contact of soft parts, may limit mobility
- hormones: relaxin produced near birth increases pubic symphysis joint
- disuse: restricts movement, decreases synovial fluid, muscles atrophy, joint becomes less mobile & flexible
synovial joint movements
uniaxial: one plane (elbow)
biaxial: two planes (metacarpophalangeal)
triaxial: all three planes (GH)
joints surfaces move around one another - described in 3 ways:
roll
spin
slide/glide
ROLL
one articular surface rolls on another
ex. femur rolls on tibia
SLIDE
one articular surface slides on another
ex. femur slides on tibia
SPIN
one bone moves but axis remains stationary
ex. femur spins on tibia
nerve supply to synovial joints
-contain nerve endings distributed throughout capsule & close by ligaments
-some nerve endings convey info about pain from joint to spinal cord to brain
-other nerve endings respond to degree of movement & stretch at joint
-spinal cord & brain respond by sending impulses through different nerves (motor nerves) to mm to adjust body movements
blood supply (synovial joints)
-articular cartilage = avascular
-fibrous capsule & ligaments have poor blood supply
-synovial membrane = highly vascularized with blood capillaries (deliver oxygen & nutrients to inside of joint)
four main types of movement
gliding
angular movements
rotation
special movements
gliding
simple movement
bone surfaces move back & forth / side to side on one another
movement limited due to capsules, ligaments & bone shapes
ex. intercarpals & intertarsals
angular motion
change angle between two articulating bones
ex. flexion/extension, lateral flexion, hyperextension, abduction/adduction, circumduction
hyperextension (angular motion)
found in hinge joints (elbow, interphalangeal, knee)
motion prevented by ligaments & bone alignment
special movements
(only occur at certain joints)
-elevation/depression
-protraction/retraction
-inversion/eversion
-dorsiflexion/plantarflexion
-radial deviation/ ulnar deviation
-supination/pronation
-opposition
elevation & depression
elevation: superior motion, moving up
depression: inferior motion, pressing down
protraction & retraction
protraction: to draw outwards
retraction: to draw inward
inversion & eversion
inversion: turn inward / medially
eversion: turn outward / laterally
dorsiflexion & plantar flexion
dorsiflexion: toward superior surface - standing on heels
plantar flexion: toward inferior surface - standing on toes
radial & ulnar deviation
radial: ABD wrist away from midline
ulnar: ADD wrist toward midline
supination & pronation (hand)
supination: palm turned upward
pronation: palm turned downward
supination & pronation (foot)
supination: inversion, plantar flexion, ADD
pronation: eversion, dorsiflexion, ABD
opposition
movement of thumb across hand to touch fingertips
combination of: flexion, ADD, internal rotation
range of motion (ROM)
measurement of amount of movement around specific joint
measured in degrees
2 common ways to measure ROM
PASSIVE (relaxed): therapist makes motion of joint while patient is relaxed & does not contract mm - anatomical barrier = end of PROM
ACTIVE: patient “actively” contracts voluntary mm crossing joint, moving joint through ROM - physiological barrier = end of AROM
CLOSED packed position
when articulating bones have their MAXIMUM area of contact with each other = maximum congruency
joint capsule becomes twisted, surfaces fully approximated
-maximum contact, mobility, stability
joint stability = greatest
injury in close packed: fracture/ dislocation
OPEN (loose) packed position
when joint surfaces become separated, have little congruity & minimal joint surface contact
joint capsule relaxed & untwisted
joint is under least amount of stress (which is why we most joint mobs in resting position)
=MINIMAL stability
injury in loose packed: sprains & strains, swelling occurs
capsular pattern of restriction
predictable pattern of movement restriction
occurs in synovial joint when entire joint capsule is injured / affected
result = total joint reaction
only joints controlled by mm have capsular pattern
pattern is MOST restricted to LEAST restricted
should (GH) capsular pattern of restriction
lateral rotation
ABD
medial rotation
proprioception
sensation that tells our brain where our body is in space
KINESTHESIA
perception of body movements
sensory info travels to brain relaying info about what our joints are doing, where our head & limbs are, how they are moving
sensory info is picked up by specialized receptors = proprioceptors, imbedded in mm & tendons especially surrounding our joints
PROPRIOCEPTORS (3 types in & around joints)
muscle spindles: within skeletal mm
tendon organs: within tendons
joint kinesthetic receptors: within synovial joint capsule
proprioceptors: muscle spindles
monitor changes in LENGTH of skeletal muscle
-finely controlled/ precise movements: fingers & eye movements, mm spindles are plentiful (reading music / playing instrument)
-course / forceful movements: thigh muscles, mm spindles are fewer (deadlifts)
*only mm that lack muscle spindles = tiny muscles of EAR
proprioceptors: GTO
located at junction of tendon / mm or musculotendinous junction
protect tendons & their associated muscles from damage due to excessive tension by initiation tendon reflex
when mm contracts, it exerts a force that pulls points of attachment
proprioceptors: joint kinesthetic receptors
monitor stretch in synovial joint & send info to brain for response
-present in & around articular capsules of synovial joints
free nerve endings (joint kinesthetic receptors)
in joint’s CT
Ruffini corpuscles (joint kinesthetic receptors)
in tendons: in joint capsules, slow adapting, respond to pressure
small Pacinian corpuscles (joint kinesthetic receptors)
in skin & tendons, fast adapting, in CT outside articular capsules, respond to acceleration & deceleration of joints during movement
joint ligaments (joint kinesthetic receptors)
contain receptors similar to tendon organs that adjust reflex inhibition of adjacent mm when excessive strain is placed on joint
common joint disorders (arthropathies) - SPRAIN
stretching / tearing of ligament
common joint disorders (arthropathies) - DISLOCATION
joint alignment is interrupted
abnormal separation of joint
common joint disorders (arthropathies) - SUBLUXATION
partial / incomplete dislocation of joint
common joint disorders (arthropathies) - BURSITIS
inflammation of bursa around joint
common joint disorders (arthropathies) - TENDINITIS
inflammation of tendon / tendon sheath
common joint disorders (arthropathies) - ARTHRITIS
inflammation of joint, caused by age related degeneration, past trauma, inflammatory/ immune disease, metabolic diseases (gout)
effects of aging on joints
-decreased production of synovial fluid
-decreased joint space
-articular cartilage becomes thinner
-ligaments shorten & lose some of their flexibility
-muscles weaken & weaken joints
what are the first joints affected during aging & joint degeneration?
hips, knees, L-spine
(weight bearing joints)
