Joint/Articulation
Classified by:
•Structure (composition)
•Function (range of motion)
Types of Joints
• Synarthosis –
– Immovable Joints; usually joined by strong fibers
– No joint cavity
• Examples: sutures, joint binding tooth to
socket, growth plate
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Examples: Cartilage
Amphiarthrosis
Vertebra Discs, Pubic Symphysis
No joint cavity
Slightly movable joint
Composed of fibrous joints
Composed of cartilage joints
Example: Fibrous
– Membrane between
radius and ulna
Diarthrosis/Synovial Joint
•Greater range of motion
•Joint cavity is present
•Contains synovial fluid
• Six General Characteristics
– Articular Cartilage
• Covered with hyaline
cartilage
– Joint Cavity
• Space filled with synovial
fluid
– Articular capsule
• Fibrous capsule found on the
periosteum of long bones
– Synovial fluid
• Viscous fluid contains
macrophages
• lubricates
– Reinforcing ligaments
– Fat Pads
• Extra padding
Types of Synovial Joints
Pivot Joints
• Allows for rotation
• One bone rotates around
another
Examples
Atlas and axis; Radius and ulna
Examples: knee and elbow, phalanges
Hinge Joints
• One bone fits into another
• Motion is along a single
plane
Ball and Socket
• Freely moving joint
• Head of bone articulates
with fossa of another
Examples: glenoid fossa and
humerous; acetabulum and
femur
Gliding
• Bones slide across one
another
• Bones must have flattened
or curved faces to glide
• Movement is limited
Examples: carpals, tarsals,
between vertebra
Saddle
• Shape resembles saddle
• Permits angular motion;
including circumduction but
not rotation
Examples: Thumb
Types of Movement
Gliding- two or more bones slide past each
other
• Rotation – turning
around the longitudinal
axis of body
– Pronation and
supination are a form of
rotation
• Pronation- turn palms
posterior
• Supination – turn palms
anterior (Anatomical
position)
• Terms only apply to
movement of radius
Angular Movements
-decrease or increase the angle between two bones
• Flexion – decreases the
angle between two bones
• Extension – increases the
angle between two bones
• Hyperextension –
increase the angle by > 180°
Angular Movements
flexion, extension, adduction, abduction and
circumduction
• Abduction – move away
from body’s midline
– To be abducted
• Adduction – move toward
body’s midline
– Add to body
• Circumduction – coneshaped movement
• Dorsiflexion – point the
toe up (superior)
• Plantar flexion – point the
toe down (inferior)
• Eversion – turn ankle
laterally
• Inversion- turn ankle
medially (most common
way to twist ankle)
• Protraction- move body
part anteriorly
• Retraction- move body
part posteriorly
Elevation – movement
of the body superiorly
Depression –
movement of the body
inferiorly