Test 1- Joints Flashcards
Articulation/ arthroses
- the connection of bones at a join usually to allow movement between surfaces of bones
Type and range of movements
-They are similar in all humans; but the freedom, range m and vigor of movements are limited by configurations of bones where they fit together, ligaments and muscles.
3 major classifications of joints
-synarthrodial
-amphiarthrodial
-Diarthrodial
synarthrodial
- Immovable joints
-structure such as a skull sutures
-Gomphosis such as teeth fitting into mandible or maxilla
amphiarthrodial
- Slightly movable joints
- allow slight motion to occur
- Syndesmosis
-Symphysis
-Synchondrosis
Syndesmosis
Two bones joined together by a strong ligament or an interosseus membrane that allows minimal movement between the bones
* Bones may or may not touch each
other at the actual joint
* Examples: Coracoclavicular joint,
distal tibiofibular joint
Symphysis
Joint separated by a
fibrocartilage pad that allows very slight movement
between the bones
* Examples: symphysis pubis
and intervertebral discs
Synchondrosis
Type of joint separated
by hyaline cartilage
that allows very slight
movement between
the bones
* Examples:
costochondral joints of
the ribs with the
sternum
Diarthrodial joints
- known as synovial joints
- freely movable
-sleeve like joint capsule
-secretes synovial fluids (lubrication) - six types
what provides additional support against abnormal movements/ joint openings
- capsules thickening from tough ligaments
Articular/ hyaline cartilage
- covers the articular surface ends of bones in joint cavity
-absorbs shock
-protects bone
Rom in diarthrodial joints
-important for health
- can have motion possible in one or more planes
fibrocartilage disk in diarthrodial joints
provide additional shock absorption, load distribution, and enhance stability- Those joints are :
-Medial and lateral menisci
* Glenoid labrum
* Acetabular labrum
Degree of freedom
corresponds to the cardinal planes of motion
- motion in 1 plane = 1 degree of freedom
- motion in 2 planes= 2 degrees
-motion in 3 planes= 3 degrees
six types of diarthrodial joints
Arthrodial
* Ginglymus
* Trochoid
* Condyloid
* Enarthrodial
* Sellar
Arthrodial (gliding) joints
2 plane or flat bony surfaces which butt against each other
* Little motion possible in any 1 joint articulation
* Usually work together in series of articulations
Examples of Arthrodial (gliding) joints
-Vertebral facets in
spinal column, intercarpal and
intertarsal joints
* Motions are flexion, extension,
abduction, adduction, diagonal
abduction and adduction and
rotation, (circumduction)
Ginglymus
(hinge) joint
* A uniaxial articulation
* Articular surfaces allow
motion in only one
plane
* Examples: Elbow, knee,
talocrural (ankle)
5 major factors affect total
stability and consequently
mobility of a joint
Bones
* Cartilage
* Ligaments and connective
tissue
* Muscles
* Proprioception and motor
control
Sellar
(saddle) joint
* Unique triaxial joint
* 2 reciprocally concave and
convex articular surfaces
* Example is 1st carpometacarpal
joint at thumb (some include
sternoclavicular)
* Flexion, extension, adduction and
abduction, circumduction and
slight rotation
Condyloid
(knuckle joint)
* Biaxial ball and socket
joint
* One bone with an oval
concave surface received
by another bone with an
oval convex surface
Example: 2nd, 3rd, 4th, and 5th
metacarpophalangeal or knuckles
joints, wrist articulation between
carpals and radius
* Flexion, extension, abduction and
adduction (circumduction)
Bones affect in stability
-Usually very similar in bilateral
comparisons within an individual
* Actual anatomical configuration at
joint surfaces in terms of depth and
shallowness may vary significantly
between individual
Enarthrodial, Multiaxial or triaxial ball and socket joint
Bony rounded head fitting into
a concave articular surface
* Examples: Hip and shoulder
joint
* Motions are flexion, extension,
abduction, adduction, diagonal
abduction and adduction,
rotation and circumduction
Trochoid
(pivot, screw) joint
* Also uniaxial articulation
* Example: Atlantoaxial joint: odontoid
which turns in a bony ring, proximal and
distal radioulnar joints
Diarthodial stablility
- increased joint stability leads to decreased joint mobility
-increased joint mobility leads to decreased joint stability
Cartilage affects in stability
-Structure of both hyaline cartilage and specialized cartilaginous structures (knee
menisci, glenoid labrum and acetabular labrum) further assist in joint congruency
and stability
* Normally the same in bilateral comparisons within but may vary between
individuals in size and configuration
ligaments and connective tissue affect in stability
-Provide static stability to joints
* Variances exist between individuals in degree of
restrictiveness of ligamentous tissue
* Amount of hypo- or hyperlaxity of an individual is
primarily due to proportional amount of elastin
versus collagen within joint structures
* Individuals with proportionally higher elastin to
collagen ratios are hyperlax or “loose-jointed”
whereas individuals with proportionally lower
ratios are tighte
muscles affect in stability
-Provide dynamic stability to joints
when actively contracting
* Without active tension via a
contraction muscles provide minimal
static stability
* Strength and endurance are significant
factors in stabilizing joints
* Muscle flexibility may affect the total
range of joint motion possible
what is Proprioception and motor control, along w/ affect in stability
Proprioception: subconscious
mechanism by which body is able to
regulate posture and movements by
responding to stimuli originating in
proprioceptors imbedded in joints,
tendons, muscles and inner ear
* Motor control: process by which
body actions and movements are
organized and executed
o determine the appropriate amount of muscular forces and joint activations needed
* Sensory information from environment and body must be integrated and then coordinated in a cooperative
manner between central nervous system and musculoskeletal system
* Muscle strength and endurance are not very useful in providing joint stability unless
activated precisely when needed
5 factors affecting total joint stability and mobility
-Structural integrity may be affected by acute or chronic injury
* Structures adapt over time both positively and negatively to
specific biomechanical demands placed upon them
* When any above factors are compromised additional demands
are placed on remaining structures to provide stability which, in
turn, may compromise their integrity, resulting in abnormal
mobility
* This abnormal mobility (hypermobility or hypomobility) may
lead to further pathological conditions such as tendinitis,
bursitis, arthritis, internal derangement and joint subluxations
