Chapter 9
Articulations
Mosby items and derived items © 2007, 2003 by Mosby, Inc.
Slide 1
How flexible are we?
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Articulation = joints
Classification of Joints
• Structural - named according to presence of fluid
filled joint capsule or type of connective tissue
• Functional - named according to degree of movement
allowed

Synarthroses—immovable joint

Amphiarthroses—slightly movable

Diarthroses—freely movable (synovial joints)
Fibrous joints - synarthroses - bones
fit together closely
• Syndesmoses - joints in which ligaments
connect 2 bones
• Sutures - found in skull
• Gomphoses - between root of tooth and
mandible or maxilla
Cartilagenous joints
• Bones are joined together by hyaline cartilage
or fibrocartilage

hyaline present between articulating bones.

Symphyses - joints in which pad or disk of
fibrocartilage connects two bones.
Synovial joints (diarthroses)(freely
movable)
• freely movable joints
• Joint capsule- binds together
• Synovial membrane - lines capsule
• Articular cartilage - covers bones
• Joint cavity - space between bones
– Menisci (articular disks)
– Ligaments - hold bones together
– Bursae - filled with fluid
Cadaver joint
Types of synovial joints
• Uniaxial joints

Hinge joints - allows flexion and extension
– Finger, elbow

Pivot joint - projection articulates with notch of other bone ex. First/second cervical vertebrae
• Biaxial joints

Saddle joints - only in thumb

Condyloid (ellipsoidal) joints - between radius/carpals
• Multiaxial joints

Ball and socket - shoulder and hip

Gliding joint - between vertebrae, carpals and tarsals
Shoulder joint - Humeroscapular joint

Most mobile

Ligaments - hold together bones

Tendons - attach muscle to bone

Bursae - contain fluid - shock absorption
Shoulder joint
Ball broken off humerus
Rotator cuff tears
Shoulder Replacement surgery
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Elbow joint - Classic hinge joint

Two bones coming together with one bone

Stabilization by collateral ligaments

Surrounded by joint capsule

Olecranon bursa - protection

Trauma to nerve - “funny bone”/dropped wrist

Proximal radioulnar joint - permits forearm rotation
Wrist joints - Radiocarpal

Radius articulates with carpal bones

Joint - synovial
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Intercarpal joints

Between 8 carpal bones

Stabilization by ligaments

Movements - gliding, with some
abduction and flexion
Carpometacarpal joints
• three joints

1 Thumb joint

Fingers - two joints—movements - gliding type

Thumb joint is unique and important functionally
• joint capsule is loose fitting
• Saddle-shaped - allowing for opposition
• Movements—

extension,

adduction,



abduction,
circumduction,
opposition - opposable thumb
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Metacarpophalangeal joints

Rounded heads of metacarpals articulate with
concave bases of proximal phalanges

Strengthened by collateral ligaments

movements - flexion and extension
Interphalangeal joints

hinge-type, synovial

between heads of phalanges / distal phalanges
Hip joint
• Hip Joint

Stable joint (because of head of femur and
acetabulum

A joint capsule / ligaments contribute to stability
Hip surgery
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Knee joint

Largest / most complex

most frequently injured joints

Tibiofemoral joint - supported by ligaments,
cartilage, joint capsule

Permits flexion and extension
ACL
Knee Replacement surgery
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Knee resurfacing surgery
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Ankle joint

Hinge type

synovial joint

Articulation - tibia and fibula articulate with talus

wedge-shaped
• Lateral malleolus lower than medial
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Ankle injuries

“sprained ankle”
• Involves anterior talofibular ligament

External ankle rotation injuries generally involve
bone fractures rather than ligament tears
• First-degree ankle injury—lateral malleolus fractured
• Second-degree ankle injury—both malleoli fractured
• Third-degree ankle injury—fracture of both malleoli
and articular surface of tibia
Vertebral joints

Vertebral column

Intervertebral disks - between vertebrae

Ligaments - supporting vertebrae
Types and Range of Movement
at Synovial Joints
• Measuring range of motion (ROM)

Assessment of ROM

active or passive measurement

goniometer
Joint movement (Extension, flexion
and rotation)
Joint movement - hyperextension,
abduction, adduction
Joint movement - flexion, extension
supination and pronation
Joint movement - dorsiflexion,
plantar flexion, eversion, inversion,
adduction and abduction of ankle
Joint movement - protraction,
retraction, elevation and depression
Cycle of Life: Articulations
• Bone development and the sequence of ossification
between birth and skeletal maturity affect joints

Fontanels between cranial bones disappear

Epiphysial plates ossify at maturity
• Older adults

ROM decreases

Changes in gait occur
• Skeletal diseases manifest as joint problems

Abnormal bone growth (lipping)—influences joint motion

Disease conditions can be associated with specific
developmental periods
Rheumatoid arthritis and
osteoarthritis
Caring for your joints
• Maintain ideal body
weight
• Move your body
• Stand up straight
• Use big joints when
lifting
• Pace yourself
• Listen to your body
• Don’t be static
• Sit on the floor when
you can
• Prepare yourself for
activities
• Wear safety equipment
• Ask for help