Articulations
 Introduction
 Classification of Joints
 Articular Form &
Function
 Representative
Articulations
Introduction
• Articulation
• Articular Components
Learning Objectives
• Articulation:
 Define what an articulation is
an provide several examples
• Tissue Components:
 List three tissue components
that contribute to the structure
of joints
Articulations
• Articulation
(a.k.a., joint)
 The site of contact between
bones or cartilage & bone
 Joints permit growth &
movement
 Not all joints are movable
joints
Articular Tissue
Components
• Bone
• Cartilage
• Connective tissue




ligaments
tendons
membranes
lubricating fluids
Classification of Joints
• Functional Classification:
Degree of Movement
• Structural Classification
Learning Objectives
• Joints:
 Contrast the major categories of joints,
and explain the relationship between
structure & function for each category
 Provide examples for each category of
articulation
• Synovial Joints:
 Describe the basic structure of a
synovial joint and identify accessory
structures & their functions
 Provide examples for each category of
synovial joint
Functional Classification:
Degree of Movement
• Synarthroses:
 immovable
 may involve fusion of bones
• Amphiarthroses:
 slightly movable
• Diarthroses:
 freely movable
Structural
Classification
• Bony fusion:
 synarthroses
• Fibrous joints:
 synarthroses
 amphiarthroses
• Cartilaginous joints:
 synarthroses
 amphiarthroses
• Synovial joints:
 diarthroses
Synarthroses
(No Movement)
• Fibrous:
 Suture
 interdigitated projections
 dense connective tissue bonds
 ex: btw/ bones of the skull
 Gomphosis
 bony sockets
 fibrous connective tissue bonds
 ex: btw/ teeth & jaw bones
Synarthroses
• Cartilaginous:
 Synchondrosis
 interposition of cartilage plate
 ex: epiphyseal plates
 Synostosis
 conversion of articular cartilage
causing fusion of bones: totally rigid
 ex: portions of skull & epiphyseal
lines
Amphiarthroses
(Little Movement)
• Fibrous:
 Syndesmosis
 ligamentous connection
 ex: btw/ tibia & fibula
 Symphysis
 bonded by fibrocartilage pad
 ex: btw/ right & left halves of pelvis
& btw/ adjacent vertebrae
Diarthroses
(Free Movement)
• Synovial:
– complex joint bounded by joint capsule &
containing synovial fluid
 Monaxial
 permits movement along 1 axis
 ex: elbow; ankle
 Biaxial
 permits movement along 2 axes
 ex: wrist-radius; thumb-metacarpal; ribvertebrae
 Triaxial
 permits movement along 3 axes (angular &
rotational)
 ex: shoulder; hip
Components of Synovial
Joints
• Articular capsule
 synovial membrane surrounds
synovial cavity
 secretes synovial fluid
• Articular cartilage
 hyaline-like covering of bone
surface w/in joint
 slick, smooth surface reduces
friction
Components of Synovial
Joints
• Synovial fluid
 similar to interstitial fluid w/
↑ [proteoglycans]
 secreted by fibroblast of synovial
membrane
 functions:
 lubrication of articular cartilage
 nutrient distribution to articular
cartilage
 shock absorption when joints are
compressed
Components of Synovial
Joints
• Accessory structures
 menisci (sing. meniscus)
 structure – fibrocartilage pads
 function – channel fluid flow; packing
 fat pads
 structure – adipose tissue
 function – antishock & pack joint capsule to
fill gaps during movement
 accessory ligaments
 structure – localized thickenings of capsule
 function – reinforce & strengthen; limit
rotation
Components of Synovial
Joints
• Accessory structures
(cont)
 tendons
 structure – collagen fibers of dense regular
connective tissue
 not technically part of articulation
 function – limit range of motion & provide
mechanical support
 bursae
 structure – small, synovial fluid-filled
connective tissue pockets
 function – form where ligaments &/or tendons
rub against other tissues: reduce friction
Synovial Joint:
Stabilizing Factors
• Factors:
 collagen fibers of joint capsule &
accessory ligaments
 articular surface shapes of bones
 presence of other bones, skeletal
muscles, &/or fat pads
 tension in tendons attached to the
articulating bones
• Functions:
 limit range of motion to reduce chance
of injury
 stabilize joint
Shoulder Joint –
Stabilization
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 32 sec
Articular Form &
Function (Synovial Joints)
• Describing Dynamic Motion
• Types of Movements
• Structural Classification of
Synovial Joints
Learning Objectives
• Dynamic Movement:
 Describe the dynamic
movements of the skeleton
• Synovial Joints:
 List the different types of
synovial joints, & discuss how
characteristic motions are
related to anatomical structure
Dynamic Motion
• Linear motion
 movement away from point of origin:
forward/backward & left/right
• Angular motion
 change in degree from vertical:
movement away from point of origin:
forward/backward & left/right
 circumduction – complex angular
motion
• Rotation
 movement around a vertical axis
Types of Movements:
Linear Motion
• Gliding
 Opposing surfaces slide past one
another
 ex: btw/ carpal & tarsal bones; btw/
clavicles & sternum
Wrist: Gliding Motion
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 2 sec
Types of Movements:
Angular Motion
• Flexion & Extension
 Flexion – reduces angle btw/ articulating
elements
 Extension – increases angle btw/
articulating elements
 ex: movement at elbow
• Abduction & Adduction
 Abduction – movement away from the
longitudinal axis of the body
 Adduction – movement toward the
longitudinal axis of the body
 ex: movement of arm laterally or
medially
Elbow: Flexion &
Extension
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 3 sec
Hyper-extension
• Extension beyond the range of
normal motion
 May result in injury:
“Extension” to
Knee
this position
Elbow
Wrist
Interphalangeal joints
• Normal for many joints in motion:
Hip
Wrist
Shoulder: Adduction &
Abduction
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 3 sec
Types of Movements:
Rotation
• Rotation
- Pivoting around an axis
 Left rotation & right rotation
 ex: shaking head “no”
 Medial rotation – internal or inward
rotation
 ex: rotating arm across front of body
 Lateral rotation – external or
outward rotation
 ex: rotating arm across front of body
Shoulder: Rotation
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 3 sec
Types of Movements:
Rotation
• Rotation
(cont)
 Pronation
 ex: palm front to palm back
 Supination
 ex: palm back to palm front
Types of Movements:
Complex Angular Motion
• Circumduction
 Describing a circle
 Combination of flexion, extension,
adduction, & abduction
 ex: movement of arm at shoulder
to draw a circle
Shoulder: Circumduction
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 2 sec
Wrist: Circumduction
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 2 sec
Special Movements
• Dorsiflexion
 ex: flexion of ankle to elevate sole
• Plantar flexion
 ex: flexion of ankle to elevate heel
• Inversion
 ex: twisting sole inward
• Eversion
 ex: twisting sole outward
Ankle: Plantar Flexion &
Dorsiflexion
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 3 sec
Ankle: Inversion &
Eversion
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 2 sec
Special Movements
• Opposition
 ex: movement of thumb toward palm
• Protraction
 ex: movement anteriorly in horizontal plane
• Retraction
 ex: movement posteriorly in horizontal plane
• Elevation
 ex: movement in a superior direction
• Depression
 ex: movement in an inferior direction
• Lateral flexion
 ex: movement of vertebral column laterally
Nice Schnozz,
eh?
Elevation
Hand/Thumb: Opposition
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 2 sec
Synovial Joint
Classification
• Gliding (planar) joints
 flat articular surfaces
 biaxial – permit linear motion
 ex: intercarpal & intertarsal joints;
sacroiliac; tibiofibular joints
• Hinge (ginglymus) joints
 monaxial – permit angular motion
 ex: humeroulnar (elbow) joint;
interphalangeal joints
Synovial Joint
Classification
• Pivot (trochoid) joints
 monaxial – permit rotation
 ex: atlas-axis joint
• Ellipsoidal (condylar) joints
 oval face articulates w/ depression
 biaxial – permits any angular
movement including circumduction
 ex: radius & proximal carpals;
proximal phalanges & metacarpals
Synovial Joint
Classification
• Saddle (sellaris) joints
 faces w/ concave & convex regions
 biaxial – permits angular &
circumduction; no rotation
 ex: carpometacarpal joint of thumb
• Ball & Socket joints
 round head w/ cup-shaped depression
 triaxial – permits any angular
movement including circumduction &
rotation
 ex: shoulder & hip joints
Synovial Joint
Movements
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 36 sec
Representative
Articulations
•
•
•
•
•
Intervertebral Articulations
The Shoulder Joint
The Elbow Joint
The Hip Joint
The Knee Joint
Learning Objectives
• Articular Features:
 Describe the articulations btw/ the
vertebrae of the vertebral column
 Describe the articular features of
the shoulder, elbow, hip, & knee
• Joint Mobility:
 Explain the relationship btw/ joint
strength & mobility
Intervertebral
Articulations
• Gliding amphiarthroses
• Structural factors:
 Intervertebral discs
btw/ vertebrae
nucleus pulposus – soft, gelatinous,
elastic core of disc
• Stabilizing factors:
 intervertebral ligaments –
anterior
longitudinal; posterior longitudinal; ligamentum
flavum; interspinous; supraspinous
Vertebral Movements
• flexion – bending forward
• extension – bending backward
• hyperextension – bending beyond
anatomical position
• lateral flexion – bending to the side
• rotation – atlas & axis joint (only
pivot diarthrosis in vertebral column)
The Shoulder Joint
(Glenohumeral or Scapulahumeral)
• Ball & socket diarthrosis
• Structural factors
 head of humerus w/in shallow
glenoid cavity of scapula
• Stabilizing factors:
 interlocking bones
 ligaments – glenohumeral; coracohumeral;
coracoacromial; coracoclavicular
 rotator cuff muscles –
supraspinatus;
infraspinatus; subscapularis; teres minor
Shoulder Joint – Detail
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 32 sec
Widest range of movement
of any
joint
Shoulder
Movements
• flexion – elevating humerus & moving
horizontally across chest
• extension/hyperextension – elevating
humerus & moving horizontally away from
chest
• abduction – moving arm laterally (outward)
in vertical plane
• adduction – moving arm medially (inward)
in vertical plane
• circumduction – moving extended arm to
trace a circle
• rotation – twisting extended arm dorsally &
ventrally
The Elbow Joint
(Olecranal)
• Hinge diarthrosis
• Structural factors
 troclear surface of humerus interlocks w/
troclear notch of ulna (stabilizing factor)
• Stabilizing factors
 interlocking bones
 thick articular capsule
 ligaments – radial collateral; annular; ulnar
collateral
Elbow Movements
• flexion – bending forearm forward
toward upper arm
• extension – bending forearm away
from upper arm
The Hip Joint
(Coxal)
• Ball & socket diarthrosis
• Structural factors
 head of the femur lies w/in deep
acetabulum of the coxal bone
• Stabilizing factors
 interlocking bones
 dense articular capsule
 ligaments – iliofemoral; pubofemoral;
ischiofemoral; transverse acetabular; femoral
head ligament
 muscular padding
Coxal Articulation
Note
stabilizing
effect of
muscles
nd
2
Widest range of
Hip
Movements
movement
of any joint
• flexion – elevating femur & moving
horizontally toward pubis
• extension/hyperextension – lowering femur
& moving horizontally away from pubis
• abduction – extending leg laterally
(outward) in vertical plane
• adduction – moving leg medially (inward) in
vertical plane
• circumduction – moving extended leg to
trace a circle
• rotation – twisting leg dorsally & ventrally
The Knee Joint
(Femurotibial)
• Hinge diarthrosis – complex
• Structural factors
 actually 3 separate joints
2 - btw/ lateral & medial condyles of
femur & tibia
1 btw/ patella & femur
 no unified joint capsule
 no common synovial cavity
 medial & lateral menisci
The Knee Joint
Note• Stabilizing factors
 fat pads
stabilizing
 ligaments – patellar; 2 popliteal;
effect of
pads, anterior cruciate & posterior
cruciate; tibial collateral; fibular
menisci,collateral
&
ligaments
 medial & lateral menisci
Knee Joint – Detail
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• MOV Video plays about 18 sec
Knee Movements
• flexion – bending lower leg backward
• extension – bending lower leg
forward
• rotation – extremely limited
Locking of the knee – in extended –
somewhat hyperextended – position
permits standing for long periods
w/out use of muscles that extend the
leg
Review of Important
Joint Movements
• To View Video:
– Move mouse cursor over slide titlelink
– When hand appears, click once
• ASF Video plays about 2-1/4 min