Chapter 8: Joints
Objectives: 1) Know the basic types
of movement
2) Know the basic
disorders that affect
the joints
Reminders: Quiz Monday
Types of Movements
at Synovial Joints
• Flexion/Extension
– movement in anterior/posterior
plane
• flexion reduces the angle
• extension increases the angle
• in the anatomical position, all major
joints (except ankle) are at full
extension.
• extension past the anatomical position
is called hyperextension
• example is bending your neck backwards
to look at the sky
Types of Movements
at Synovial Joints
• Abduction/Adduction
– angular movement in frontal
plane
• abduction moves away from the
longitudinal axis of the body
• adduction moving towards the
longitudinal axis of the body
Types of Movements
at Synovial Joints
• Circumduction
– angular motion,
without rotation
Types of Movements
at Synovial Joints
• Rotation
– Left or right rotation
– Medial rotation (inward rotation)
• rotates toward axis
– Lateral rotation (outward rotation)
• rotates away from axis
Types of Movements
at Synovial Joints
• Rotation of the forearm
– Pronation:
• rotates forearm, radius over ulna
– Supination:
• forearm in anatomical position
Special Movements
• Inversion/Eversion
– twisting motion of the foot that turns sole inward
(inversion) or outward (eversion)
Special Movements
• Dorsiflexion/Plantar flexion
– flexion at ankle joint
• dorsiflexion elevates sole
• plantar flexion elevates heel
NOTE: it is acceptable
to use the terms flexion and
extension for these
movements of the ankle.
Special Movements
• Opposition
– thumb movement toward fingers or palm (grasping)
• only primates and a few other species have opposable thumbs
• humans can move their thumbs farther across their hand than any other primate
Special Movements
• Protraction
– moves anteriorly
– in the horizontal plane (pushing forward)
• Retraction
– opposite of protraction
– moving anteriorly (pulling back)
Special Movements
• Elevation
– moves in superior direction (up)
• Depression
– moves in inferior direction (down)
shoulder shrug
Special Movements
• Lateral Flexion
– bends vertebral column from side to side
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
• There are more than 100 different types of
inflammatory or degenerative diseases that
damage the joints
• 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
– aka “wear-and-tear” arthritis
– aka degenerative joint disease (DJD)
• affects women more than men
• affects older population
– as one ages, cartilage is destroyed more quickly than it is
replaced
– results in 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
• Typical onset between the
ages of 40 to 50
• Signs and symptoms
include joint tenderness,
anemia, osteoporosis,
muscle atrophy, and
cardiovascular problems
Gouty Arthritis (Gout)
• Deposition of uric acid crystals in joints
and soft tissues, followed by an
inflammation response
• More common in men
• 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
anti-inflammatory drugs, and
glucocorticoids