Chapter 7
Joints
Copyright 2010, John Wiley & Sons, Inc.
End of Chapter 7

Copyright 2010 John Wiley & Sons, Inc.
All rights reserved. Reproduction or translation of this
work beyond that permitted in section 117 of the 1976
United States Copyright Act without express permission
of the copyright owner is unlawful. Request for further
information should be addressed to the Permission
Department, John Wiley & Sons, Inc. The purchaser may
make back-up copies for his/her own use only and not
for distribution or resale. The Publishers assumes no
responsibility for errors, omissions, or damages caused
by the use of theses programs or from the use of the
information herein.
Copyright 2010, John Wiley & Sons, Inc.
Joints


Points where bones meet
Classifications

Structurally: by their anatomy
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
Fibrous, cartilaginous, or synovial
Functionally: by the degree of movement they
permit

Immovable, slightly movable, and freely movable
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Structural Classification

Based on what is between bones:
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Space (or not)
Type of connective tissue present
Types
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Fibrous joints - no cavity, just dense irregular
connective tissue
Cartilaginous joints - no cavity, bones held
together by cartilage
Synovial joints - have synovial cavity, dense
irregular tissue of articular capsule, and often
ligaments
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Functional Classification


Based on degree of movement they permit
Types
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Synarthrosis: immovable
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Amphiarthrosis: slightly movable
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Pelvis, sutures, teeth
Epiphyseal plate, tibia-fibula, vertebrae, pelvic symphysis
Diarthrosis: freely movable
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Most joints of the body
All diarthrotic joints are synovial
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Fibrous Joints
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Suture (synarthrosis)
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Joined by thin layer of dense fibrous connective
tissue
Example: between bones of skull
Syndesmosis

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Greater distance between bones and greater
amount of dense irregular connective tissue
Examples
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
Distal tibia to distal fibula (amphiarthrosis)
Gomphosis (synarthrosis): tooth root in socket
(alveolar process) of mandible or maxilla
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Fibrous Joints

Interosseous membrane (amphiarthrosis)


Has greater amount of dense irregular
connective tissue
Examples: extensive membranes between shafts
of some long bones


Radius-ulna
Tibia-fibula
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Fibrous Joints
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Fibrous Joints
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Fibrous Joints
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Cartilaginous Joints

Synchondrosis (synarthrosis)
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
Cartilage connects two areas of bone
Example
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Epiphyseal (growth) plate connecting epiphysis and
diaphysis of long bone (synarthrosis)
Symphysis (amphiarthrosos)


Cartilage connects two bones, but a broad disc of
fibrocartilage is present also
Examples: pubic symphysis and intervertebral
discs
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Cartilaginous Joints
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Cartilaginous Joints
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Synovial Joints: Structure

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Synovial cavity: space containing fluid
Articular cartilage
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Covers ends of bones, absorbs shock
Articular capsule

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Inner layer: synovial membrane that secretes
synovial fluid (reduces friction, supplies nutrients)
Outer layer: dense, irregular connective tissue
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Synovial Joints: Structure

In some cases synovial joints include:
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Ligaments (either inside or outside of joint cavity)
Menisci (cartilage discs)
Articular fat pads
Bursae
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Sacs made of synovial membranes containing fluid
Located where friction can occur
Examples: between skin-bone, tendons-bones,
muscles-bones, ligaments-bones
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Synovial Joints: Structure
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Knee Joint
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Knee Joint
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Knee Joint
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Knee Joint
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Types of Movements at Synovial Joints
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Gliding
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Flexion
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Decrease in angle between articulating bones
Extension
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Flat bone surfaces moving across each other
Increase in angle between articulating bones
In anatomical position the body is in full extension
Hyperextension

Bending beyond 180o degrees, such as moving
humerus backwards behind anatomical position
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Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
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Movements

Abduction
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Adduction
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Movement of bone toward midline
Circumduction

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Movement of bone away from midline
Movement of distal end in a circle
Rotation

Bone revolves around its own longitudinal axis
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Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Types of Movements at Synovial Joints
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Special Movements
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Elevation
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Depression
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Movement downward
Protraction


Movement upward
Movement forward
Retraction

Movement backward into anatomical position
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Special Movements at Synovial Joints
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Special Movements at Synovial Joints
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Special Movements
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Inversion
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Eversion
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Move soles laterally
Dorsiflexion
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Move soles medially
Bend foot toward dorsum (“stand on heels”)
Plantar flexion

Bend foot toward plantar surface (“stand on toes”)
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Special Movements at Synovial Joints
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Special Movements at Synovial Joints
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Special Movements at Synovial Joints

Supination
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Movement of forearm so palms face forward or
upward
Pronation

Movement of forearm so palms face backward or
downward
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Special Movements at Synovial Joints
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Six Types of Synovial Joints

Planar joints
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Articulating surfaces flat or slightly curved
Examples: between carpals, tarsals, sternumclavicle, scapula-clavicle
Movements: gliding
Hinge joints
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Convex-to-concave surfaces
Examples: elbow, knee, ankle, interphalangeal
Movements: flexion (F) and extension (E) only
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Types of Synovial Joints
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Pivot joints
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Rounded surface with ring formed by bone and
ligament
Examples: atlantoaxial joint (to turn head to say
“no”) and radius-ulna for pronation-supination
Movement: rotation (ROT)
Condyloid joints
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Convex oval surface to concave oval surface
Examples: wrist, metacarpophalangeal-2 to -5
joints
Movements F, E, ABD, ADD
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Types of Synovial Joints

Saddle joints
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One side of saddle-shaped, other like a rider
astride it
Example: trapezium (carpal) to metacarpal-1
(thumb)
Movements: triaxial (F, E, ABD, ADD, ROT)
Ball-and-socket joints
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Ball-like surface into cuplike socket surface
Example: shoulder, hip
Movements: triaxial (F, E, ABD, ADD, CIR, ROT)
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Types of Synovial Joints
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Types of Synovial Joints
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Types of Synovial Joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Synovial Joints
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Types of Synovial Joints
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Types of Synovial Joints
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Details of a Synovial Joint: Knee Joint

See slides 10a-d
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Ligaments
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Menisci (medial and lateral)
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Tibial and fibular collateral ligaments
Anterior cruciate ligament (ACL): 70 % of knee injuries
Posterior cruciate ligament (PCL)
Fibrocartilage discs that increase stability of knee joint
Bursae
Arthroplasty
Knee replacement: total or partial
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Aging of Joints
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Decrease in production of synovial fluid
Thinning of articular cartilage
Ligaments shorten and lose flexibility
Influenced by genetic factors
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Common Disorders of Joints
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Common joint injuries
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Rotator cuff injury
Separated shoulder
Tennis elbow
Dislocation of the radial head
Knee injuries: swollen knee, rupture of tibial
collateral ligaments, dislocated knee
Rheumatism: rheumatoid arthritis, osteoarthritis
Ligaments shorten and lose flexibility
Influenced by genetic factors
Copyright 2010, John Wiley & Sons, Inc.
End of Chapter 7

Copyright 2010 John Wiley & Sons, Inc.
All rights reserved. Reproduction or translation of this
work beyond that permitted in section 117 of the 1976
United States Copyright Act without express permission
of the copyright owner is unlawful. Request for further
information should be addressed to the Permission
Department, John Wiley & Sons, Inc. The purchaser may
make back-up copies for his/her own use only and not
for distribution or resale. The Publishers assumes no
responsibility for errors, omissions, or damages caused
by the use of theses programs or from the use of the
information herein.
Copyright 2010, John Wiley & Sons, Inc.