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Chapter
Joints
Classification of Joints
1) Type of tissue and 2) type of movement
used as classification
1. Type of tissue (3 types):
1. Fibrous Joints: collagen fibers
2. Cartilaginous Joints: cartilage
3. Synovial Joints: dense irregular CT
forming capsule & accessory
ligaments
2. Type of movement (3 types)
1. synarthrotic – no movement
2. amphiarthrotic – slight movement
3. diarthrotic – freely movable
• Joints hold bones
together but permit
movement
• Point of contact
– between 2 bones
– between cartilage
and bone
– between teeth and
bones
• Arthrology = study of
joints
• Kinesiology = study of
motion
9-1
1. Fibrous Joints
9-2
1.
•
Lack a synovial
cavity
• Bones held
closely together
by fibrous CT
(collagen)
• Synarthrosis or
Amphiarthrosis)
3 Fibrous joint types:
1. Sutures
2. Syndesmoses
3. Gomphoses
Sutures
• Thin layer of dense
fibrous CT unites bones
of skull
• Immovable (synarthrosis)
9-3
2.
9-4
3.
Syndesmosis
• Fibrous joint: bones united by ligament
• Amphiarthrosis
E.G., Anterior tibiofibular joint and Interosseous
membrane
9-5
Gomphosis
• Ligament holds cone-shaped peg in bony
socket
• Amphiarthrosis)
E.G., Teeth in alveolar processes
9-6
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2. Cartilaginous Joints
1.
Synchondrosis
•
•
•
Lacks a synovial cavity
Synarthroses or Amphiarthroses
Bones tightly connected by fibrocartilage
or hyaline cartilage
• 2 types of cartilagenous joints:
1. synchondroses
2. symphyses
Bony Joints
• Connecting material is hyaline cartilage
• Immovable (synarthrosis)
• Epiphyseal plate or joints between ribs and
sternum
9-7
2.
9-8
3. Synovial Joints
Symphysis
•
•
•
• Fibrocartilage is
connecting
material
• Amphiarthroses
E.G., Intervertebral
discs and pubic
symphysis
•
Synovial Cavity: separates articulating bones
Diarthroses
Articular capsule:
1. Fibrous capsule
2. Synovial membrane
- inner lining of capsule
- secretes synovial fluid
-(nutrients to articular cartilage)
Articular cartilage
9-9
Synovial Joint
9-10
Other Special Features associated with joints
Articular discs or menisci:
– Fibro. Cart. Growth inwards from capsule
– Absorbs shock/pressure & a good fit
Accessory ligaments & tendons
Bursae = saclike structures between structures
9-11
9-12
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Tendon Sheaths and Bursae
Tendon of flexor carpi radialis
Joints and Lever Systems
Tendons of flexor digitorum superficialis
and flexor digitorum profundus
Tendon of flexor pollicis longus
• long bones act as levers to enhance speed or power of limb
movements
Ulnar bursa (cut)
Radial bursa (cut)
• lever – any elongated, rigid object that rotates around a fixed
point called a fulcrum
Flexor retinaculum (cut)
• rotation occurs when an effort applied overcomes resistance
(load) at some other point
Lumbrical muscles
– resistance arm and effort arm are described relative to fulcrum
Tendons of flexor digitorum
superficialis
Tendon sheaths
Resistance
(load)
Tendon sheath (opened)
Effort
Tendon of flexor digitorum
superficialis
R
Tendon of flexor digitorum
profundus
E
Resistance arm
Figure 9.6
9-13
Effort arm
9-14
F
Fulcrum
First-Class Lever
Second-Class Lever
Resistance
Effort
Resistance
R
E
Effort
R
Resistance
Resistance
R
R
Resistance
E
F
F
E
F
Fulcrum
Fulcrum
Effort
Resistance
(a) First-class lever
Effort
E
F
Fulcrum
Effort
F
F
Fulcrum
(b) Second-class lever
Figure 9.9b
Effort
• has fulcrum in the middle between effort and resistance (RFE)
• resistance between fulcrum and effort (FRE)
9-15
Range of Motion
Third-Class Lever
Fulcrum
Resistance
F
Effort
E
E
R
Effort
Resistance
Effort
F
Fulcrum
Resistance
9-16
R
(c) Third-class lever
F
Figure 9.9c
• effort between the resistance and the fulcrum (REF)
– Most joints of body
9-17
• range of motion (ROM) – degrees through which a
joint can move
• range of motion determined by:
– structure of the articular surfaces
– strength & tautness of ligaments and joint
capsules
– action of the muscles and tendons
• nervous system monitors joint position and
muscle tone
• muscle tone – state of tension maintained in
resting muscles
9-18
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Types of Synovial Joints
Axes of Rotation
(a) Abduction of arm
Ball-and-socket joint
(humeroscapular)
Multi- axial
(c) Internal rotation
of arm
Humerus
Hinge joint
(humeroulnar)
monoaxial
Head of humerus
Scapula
Ulna
Radius
Pivot joint
(radioulnar)
monoaxial
Ulna
Carpal bones
Plane joint
(intercarpal)
Biaxial
(b) Flexion of arm
• a moving bone has a relatively stationary axis of
rotation that passes through the bone in a direction
perpendicular to the plane of movement
• multiaxial joint - shoulder joint has three degrees of
freedom or axes of rotation
9-19
• other joints – monoaxial or biaxial
Types of Synovial Joints:
Saddle joint
(trapeziometacarpal)
biaxial
Carpal bone
Condylar joint
(metacarpophalangeal)
Biaxial
Metacarpal bone
Metacarpal
bone
Phalanx
Figure 9.11
9-20
Hinge Joint
Plane Joint (Gliding Joint)
• Convex surface fits into
concave surface
(monoaxial)
• Examples
– Knee, elbow, ankle,
interphalangeal joints
• Bone surfaces are flat
or slightly curved
• Side to side movement
(biaxial)
• Rotation prevented by
ligaments
• Examples
– intercarpal or
intertarsal joints
– sternoclavicular joint
– vertebrocostal joints
9-21
Pivot Joint
9-22
Condylar or Ellipsoidal Joint
• Rounded surface
articulates with ring &
ligament (monaxial)
• Examples:
– Proximal radioulnar
joint
• Oval-shaped projection fits into oval depression
• Biaxial
• Examples
– wrist and metacarpophalangeal joints for digits 2 to 5
9-23
9-24
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Ball and Socket Joint
Saddle Joint
• Ball fitting into a cuplike
depression
• Multiaxial
– flexion/extension
– abduction/adduction
– rotation
• Examples
– shoulder joint
– hip joint
• One bone saddled-shaped; other bone fits as a
person would sitting in that saddle
• Biaxial
– Circumduction: allows tip of thumb travel in circle
– Opposition: tip of thumb to touch tip of other fingers
9-25
9-26
Movements of Synovial Joints
Flexion, Extension and Hyperextension
• vocabulary of movements of synovial joints used in
kinesiology, physical therapy, and other medical
fields
• zero position – position of joint when person is in
standard anatomical position
– Joint movements are described as deviating
from the zero position or returning to it
• flexion – decreases joint
angle
• extension – straightens
a joint and generally
returns a body part to
the zero position
Flexion
Extension
(a)
Hyperextension
• hyperextension – further
extension beyond zero
position
Extension
9-27
Flexion
(b)
Flexion, Extension and Hyperextension
Movements of Head and Trunk
Flexion
Hip
flexion
Hyperextension
(c)
(a) Flexion
(b) Hyperextension
(c) Lateral flexion
Knee
flexion
flexion, hyperextension, and lateral flexion of
vertebral column
Extension
(d)
9-29
9-30
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Abduction and Adduction
Elevation and Depression
Figure 9.13a,b
(a) Abduction
(a) Elevation
(b) Adduction
• abduction - movement in the frontal plane away from
midline
– hyperabduction – raise arm over back or front of head
• adduction - movement in the frontal plane back toward
midline
9-31
– hyperadduction – crossing fingers, crossing ankles
• depression – lowers a body part in the same plane
9-32
Protraction and Retraction
• protraction –
anterior movement
of body part in
transverse
(horizontal) plane
(b) Depression
• elevation - a movement that raises a body part
vertically in the frontal plane
Circumduction
• circumduction - one end
of appendage remains
stationary while other
end makes circular
motion
(a) Protraction
sequence of flexion,
abduction, extension and
adduction movements
• retraction –
posterior
movement
(b) Retraction
9-33
Rotation
Supination and Pronation
• primarily forearm
movements
• rotation – bone spins on
its longitudinal axis
• supination – turns palm to
face anteriorly or upward
• medial (internal)
• lateral (external)
• pronation – turns the palm
to face posteriorly or
downward
(a) Supination
(a) Medial (internal) rotation
(b) Pronation
(b) Lateral (external) rotation
9-35
9-36
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Special Movements of Mandible
Rotation of Trunk and Head
Copyright © The McGraw-Hill Companies, Inc. Permision required for reproduction or display.
(a) Protraction
(b) Retraction
(c) Lateral excursion
(d) Medial excursion
Figure 9.20
© The McGraw-Hill Companies, Inc./Timothy L. Vacula, photographer
Figure 9.19d,e
© The McGraw-Hill Companies, Inc./Timothy L. Vacula, photographer
right and left rotation of trunk
right and left rotation of head
9-37
• lateral excursion – right or left movement from the
zero position
• medial excursion - movement back to the median,
zero position
• protraction – retraction
elevation - depression
9-38
Special Movements of the Foot
Special Movement of
Hand and Digits
Dorsiflexion
Zero
position
(b) Inversion
(c) Eversion
Plantar flexion
(a) Flexion of ankle
(a) Radial flexion
(b) Ulnar flexion
• supination of foot – complex combination of plantar
flexion, inversion, and adduction
• pronation of foot – complex combination of
dorsiflexion, eversion, and abduction
(c) Abduction of fingers
9-39
(d) Palmar abduction of thumb
9-40
(e) Opposition of thumb
Some selected joints: Shoulder Joint
• Head of
humerus and
glenoid cavity of
scapula
• Ball and socket
• All types of
movement
• Glenohumeral
joint
9-41
Glenohumeral (Shoulder) Joint
• Articular capsule from glenoid cavity to
anatomical neck
9-42
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Articular Capsule of the Elbow Joint
Supporting Structures at Shoulder
9-43
9-44
Hip Joint Capsule
Hip Joint
• Head of femur and
acetabulum of hip
bone
• Ball and socket
type of joint
• All types of
movement
possible
• Dense, strong capsule reinforced by
ligaments
– iliofemoral ligament
– ischiofemoral ligament
– pubofemoral ligament
9-45
9-46
Knee Joint – Sagittal Section
Quadriceps
femoris tendon
Suprapatellar
bursa
Bursa under lateral
head of gastrocnemius
Prepatellar bursa
Articular cartilage
Synovial membrane
Meniscus
Infrapatellar fat pad
Superficial
infrapatellar bursa
Patellar ligament
Deep
infrapatellar bursa
(c) Sagittal section
• knee joint has at least 13 bursae
9-48
9-47
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Ankle Joint (talocural)
Knee Joint
Patellar surface
Medial condyle
Lateral
condyle
Posterior cruciate
ligament
Fibular
collateral
ligament
Anterior cruciate
ligament
Lateral
meniscus
Anterior cruciate
ligament
Tibial
collateral
ligament
Fibular collateral
ligament
Medial
meniscus
Lateral meniscus
• Tibia & fibula
with talus
• Hinge
• Inversion,
eversion,
plantarflexion &
dorsiflexion
Medial meniscus
Tibial collateral
ligament
Transverse
ligament
Articular cartilage
of tibia
Posterior
cruciate
ligament
Patellar ligament
(cut)
(a) Anterior view
(b) Posterior view
9-49
9-50
Osteoarthritis – “wear & tear” arthritis
• Degenerative joint disease – cartilage is
eventually worn away
• Only cartilage is affected not synovial
membrane
• Deterioration of cartilage produce bone
spurs (grow into cavity)
• Pain upon awakening--disappears with
movement
9-51
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Rheumatoid Arthritis
• Autoimmune – Antibody
attacks
• Synovial membrane- &
cartilage destroyed
1. Inflammation of synovial
membrane
2. Granulation tissue
produced (erodes cart.)
3. Fibrous tissue forms
between bones
4. Final step is joint
ossification
10