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Chapter 9:
Synovial Joints
Interactive pgs. 263-279
Synovial Joints: Range of Motion
•
•
•
•
Nonaxial – slipping movements only
Uniaxial – movement in one plane
Biaxial – movement in two planes
Multiaxial – movement in or around all
three planes
Linear Motion
• Also called gliding
• 2 surfaces slide past each other:
– between carpal or tarsal bones
Flexion/Extension
•Angular motion in A/P plane
•Flexion reduces angle
between elements
•Extension Increases angle
between elements
Figure 9–3a
Abduction/Adduction
•Angular motion in frontal plane
•Abduction moves away from
longitudinal axis
•Adduction moves toward
longitudinal axis
Figure 9–3b, c
Circumduction
• Circular motion
without rotation
• Angular motion
Figure 9–3d
Rotation
• Left or right rotation
• Medial rotation (inward rotation):
– rotates toward axis
• Lateral rotation (outward rotation):
– rotates away from axis
Pronation and Supination
• Pronation:
– rotates forearm, radius over ulna
• Supination:
– forearm in anatomical position
Inversion and Eversion
• Inversion:
– twists sole of
foot medially
• Eversion:
– twists sole of
foot laterally
Figure 9–5a
Dorsiflexion and Plantar Flexion
• Dorsiflexion:
– flexion at ankle
(lifting toes)
• Plantar flexion:
– extension at ankle
(pointing toes)
Figure 9–5b
Opposition
• Thumb movement toward
fingers or palm (grasping)
Figure 9–5c
Protraction and Retraction
• Protraction:
– moves anteriorly
– in the horizontal plane
(pushing forward)
• Retraction:
– opposite of protraction
– moving anteriorly (pulling
back)
Figure 9–5d
Elevation and Depression
• Elevation:
– moves in superior direction (up)
• Depression:
– moves in inferior direction (down)
Lateral Flexion
• Bends vertebral
column from side
to side
Figure 9–5f
6 subtypes of synovial joints
•
•
•
•
•
•
Gliding – intercarpals, SI
Pivot – atlas/axis, radioulnar
Hinge – elbow, knee, TMJ, interphalangeal
Ellipsoidal – Occ/C1, radius to carpals
Saddle – trapezium to 1st metacarpal
Ball & socket – shoulder/hip
• Plane joints
– Articular surfaces are
essentially flat
– Allow only slipping or gliding
movements
– Only examples of nonaxial
joints
• Hinge joints
– Cylindrical projections of one bone fits into
a trough-shaped surface on another
– Motion is along a single plane
– Uniaxial joints permit flexion and extension
only
– Examples: elbow and interphalangeal
joints
• Pivot joints
– bone protrudes into a “sleeve,”
or ring, composed of bone (and
possibly ligaments) of another
– Only uniaxial movement allowed
– Examples: joint between the axis
and the dens, and the proximal
radioulnar joint
• Condyloid joints
– Oval articular surface of one bone fits
into a complementary depression in
another
– Both articular surfaces are oval
– Biaxial joints permit all angular
motions
– Examples: radiocarpal (wrist) joints,
and metacarpophalangeal (knuckle)
joints
• Saddle Joints
– Similar to condyloid joints but
allow greater movement
– Each articular surface has both a
concave and a convex surface
– Example: carpometacarpal joint
of the thumb
• Ball-and-Socket Joints
– A spherical or hemispherical head of one
bone articulates with a cuplike socket of
another
– Multiaxial joints permit the most freely
moving synovial joints
– Examples: shoulder and hip joints
Intervertebral Articulations
• C2 to L5 spinal vertebrae
articulate:
– at inferior and superior
articular processes (gliding
joints)
– between adjacent vertebral
bodies (symphyseal joints)
Figure 9–7
Intervertebral Discs
• Intervertebral discs:
– pads of fibrocartilage that separate vertebral bodies
• Anulus fibrosus:
– tough outer layer that attaches disc to vertebrae
• Nucleus pulposus:
– elastic, gelatinous core that absorbs shocks
6 Intervertebral Ligaments
1. Anterior longitudinal ligament:
–
connects anterior bodies
2. Posterior longitudinal ligament:
–
connects posterior bodies
3. Ligamentum flavum:
–
connects laminae
4. Interspinous ligament:
–
connects spinous processes
5. Supraspinous ligament:
–
connects tips of spinous processes (C7 to sacrum)
6. Ligamentum nuchae:
–
continues supraspinous ligament (C7 to skull)
Damage to Intervertebral Discs
• Slipped disc:
– bulge in anulus fibrosus
– invades vertebral canal
• Herniated disc:
– nucleus pulposus breaks through anulus fibrosus
– presses on spinal cord or nerves
The Knee Joint
Figure 9–12a, b
The Knee Joint
• 2 femur–tibia articulations:
– 1 at medial and lateral condyles
– 1 between patella and patellar surface of femur
7 Ligaments of the Knee Joint
• Patellar ligament (anterior)
• 2 popliteal ligaments (posterior)
• Anterior and posterior cruciate ligaments (inside
joint capsule)
• Tibial collateral ligament (medial)
• Fibular collateral ligament (lateral)
• Medial and lateral menisci: fibrocartilage pads
– at femur–tibia articulations to cushion and stabilize joint
& give lateral support
Sprains
• The ligaments reinforcing a joint are stretched or
torn
• Partially torn ligaments slowly repair themselves
• Completely torn ligaments require prompt surgical
repair
Strains
•The muscles or tendons are stretched or torn
•Healing generally better than with a sprain,
however it depends on the location of the strain
with relationship of the joint
Inflammatory and Degenerative
Conditions
• Bursitis
– An inflammation of a bursa, usually caused by a
blow or friction
– Symptoms are pain and swelling
– Treated with anti-inflammatory drugs; excessive
fluid may be aspirated
• Tendonitis
– Inflammation of tendon sheaths typically caused by
overuse
– Symptoms and treatment are similar to bursitis
Arthritis
• More than 100 different types of inflammatory
or degenerative diseases that damage the joints
• Most widespread crippling disease in the U.S.
• Symptoms – pain, stiffness, and joint swelling
• Acute forms are caused by bacteria and are
treated with antibiotics
• Chronic forms include osteoarthritis, rheumatoid
arthritis, and gouty arthritis
Osteoarthritis (OA)
• Most common chronic arthritis; often called “wear-andtear” arthritis
• AKA: Degenerative Joint Disease (DJD)
• Affects women more than men
• 85% of all Americans develop OA
• More prevalent in the aged, and is probably related to
the normal aging process
• As one ages, cartilage is destroyed more quickly than it
is replaced
• The exposed bone ends thicken, enlarge, form bone
spurs, and restrict movement
• Joints most affected are the cervical and lumbar spine,
fingers, knuckles, knees, and hips
Rheumatoid Arthritis (RA)
• Chronic, inflammatory,
autoimmune disease of
unknown cause, with an
insidious onset
• Usually arises between the
ages of 40 to 50, but may
occur at any age
• Signs and symptoms include
joint tenderness, anemia,
osteoporosis, muscle atrophy,
and cardiovascular problems
– The course of RA is marked with
exacerbations and remissions
Gouty Arthritis
• Deposition of uric acid crystals in joints and
soft tissues, followed by an inflammation
response
• Typically, gouty arthritis affects the joint at the
base of the great toe
• In untreated gouty arthritis, the bone ends
fuse and immobilize the joint
• Treatment – colchicine, nonsteroidal antiinflammatory drugs, and glucocorticoids