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Chapter Eight
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Joints
and
Movements
Major Types of Joints
Three types based on tissue type connecting bones and presence
or absence of a fluid filled joint capsule
Fibrous – connection of bones with fibrous connective tissue, no
joint capsule
Cartilaginous – two bones connected by hyaline or fibrocartilage
Synovial – joints with fluid filled capsules
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Fibrous Joints
Sutures – joints between bones of the skull. Dense regular
connective tissue plus periosteum of bone along with
interdigitations of bone make these very strong joints.
Fontanels – regions between sutures of newborn skulls.
Sutures may fuse completely in older adults (synostosis)
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Other Fibrous Joints
Syndesmosis – the joining of two
bones by ligaments as seen between
the radius & ulna
Gomphoses – specialized fibrous
joints between peg-like structures and
sockets. Example: teeth fitting in
sockets (fibers connect root to socket)
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Cartilaginous Joints
Joining of two bones by either fibrocartilage or hyaline cartilage:
Synchondroses – joined with hyaline cartilage – little movement
e.g. 1st rib & sternum
Sympheses – joined by fibrocartilage, may show slight
movement. e.g. pubic symphysis, manubrium/body of sternum
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Synovial Joints
Characterized by having a fluid filled joint capsule. These are
complex joints.
Articular cartilage - covers surface of both bones
Fibrous capsule - makes up outer layer of joint capsule (may
also form ligaments inside the capsule)
Synovial membrane - makes up inner surface of capsule, not
present on articular cartilage surfaces
Synovial fluid – lubricant produced by synovial membrane
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Six Types of
Synovial Joints
!Plane/Gliding
!Saddle
!Hinge
!Pivot
!Ball & Socket
!Ellipsoid
see table 8.2 (pg 247 6th ed.) for details
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Plane or Gliding Joints
Slight movement occurs at most of
these
e.g. carpals, ribs/vertebrae
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Saddle Joints
Movement in two axes
Thumb (only joint of this type in
body)
between carpal & metacarpal of
thumb
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Hinge Joint
Movement predominantly in one axis
e.g. elbow, knee, ankle
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Pivot Joint
Rotation around an axis
e.g. radius/ulna and atlas/axis
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Ball & Socket Joint
Multiple axes
e.g. hip and shoulder
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Ellipsoid Joint
may move in multiple axes, one axis
or two depending on particular joint
(see 8.6 for examples)
e.g. Atlas/Skull,
metatarsals/phalanges
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Angular Movements
Flexion – moving a body
part toward
anterior/ventral
Extension – moving a
body part toward
posterior/dorsal
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Angular Movements
Abduction – movement away
from midline
Adduction – moving toward
midline
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Circular Movements
Rotation – Turning around a long axis
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Circular Motions
Pronation – turning palm toward posterior
Supination - turning palm toward anterior
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Circular Movements
Circumduction – combined
flexion, extension, abduction &
adduction of freely moveable
joints. This movement outlines
a cone shaped space.
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Special Movements
Elevation – raising or moving
a structure in a superior
direction
Depression – lowering or
moving a structure in an
inferior direction
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Special Movements
Protraction – moving a body part toward anterior (thrusting
forward)
Retraction – moving a part toward posterior
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Special Movements
Excursion – moving lower jaw in a side-to-side fashion
Lateral Excursion – moving jaw away from midline
Medial Excursion – moving jaw toward midline
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Special Movements
Opposition – unique motion touching thumb & little finger
Reposition – returning thumb to original postion
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Special Movements
Inversion – turning ankle so plantar surface (sole) of foot faces
medial (towards opposite foot)
Eversion – turning ankle so plantar surface of foot faces laterally
(away from opposite foot)
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Temporomandibular Joint
Synovial joint between mandible and temporal bone supported by
lateral ligament and accessory ligaments (e.g. stylomandibular
ligament)
both plane and ellipsoid motions (mostly ellipsoid)
Depression of the mandible opens the mouth
See figure 8.8 for anatomy
Malfunctions of this joint often lead to jaw pain and or ‘clicking’.
Pain may be ‘referred’ and felt in the ear rather than at the joint
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Study
All
of
those
bones
…..
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Shoulder Joint
Head of humerus fits into the glenoid fossa of the scapula.
The glenoid labrum a ring of fibrocartilage helps hold the
humerus in the fossa.
The entire joint is enclosed by a bursa
Shoulder held stable by a series of ligaments and four muscles
(rotator cuff muscles) and one tendon
Review ligaments of shoulder from table 8.2 – The tendon of the
biceps brachii holds the anterior face of the humerus.
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Hip Joint
Head of femur fits into acetabulum
Acetabulum labrum – ring of fibrocartilage which helps retain the
femur.
Ligamentum teres – ligament at center of the femur’s ball
attaches inside the acetabulum, providing some help to retain the
femur and in some people contains an artery.
This joint is supported by several external ligaments – see figure
8.10 and table 8.3 for details.
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Knee Joint
A complex ellipsoid joint that moves in a hinge-like fashion
11 ligaments support the knee (see table 8.4)
Two large condyles of femur articulate with…
… the articular cartilage of the tibia which forms lateral and
medial menisci (singular = meniscus). These dense
fibrocartilage disks may be torn and often present with symptoms
of a ‘clicking’ knee.
See Clinical Notes for some common knee problems.
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Tendon Groups of Knee
Cruciate – Two ligaments that cross internally between condyles
! Anterior
! Posterior
Collateral – two ligaments providing side support
! Medial
! Lateral
Popliteal – two ligaments providing posterior support
! Oblique
! Arcuate
Patellar – large ligament which contains patella (knee cap)
see others in table 8.4
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Ankle Joint
The distal ends of tibia and fibula articulate with the talus to form
this joint.
Calcaneofibular ligament attaches calcaneous (heel bone) to
fibula
Medial ligament – from fibula to calcaneous
Anterior talofibular from fibula to talus
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