JOINTS
JOINT
A joint is the junction or pivot point between two
or more bones.
 Movement of the body as a whole results from the
rotation of bones about individual joints.
 Joints transfer and dissipate forces produced by
gravity and muscle activation.

Dr. Michael P. Gillespie
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ARTHROLOGY
Arthrology is the study of the classification,
structure, and function of joints.
 Aging, long-term immobilization, trauma, and
disease all affect the structure and ultimate
function of joints.
 These factors influence the quality and quantity
of human movement.

Dr. Michael P. Gillespie
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CLASSIFICATION OF JOINTS

Structural Classification
Presence or absence of a space (synovial cavity)
 Type of Connective Tissue

Dr. Michael P. Gillespie

Functional Classification

Relates to the degree of movement they permit.
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CLASSIFICATION OF JOINTS BASED
ON MOVEMENT POTENTIAL

Two major types of joints exist within the body:
Synarthroses
 Diarthroses

Dr. Michael P. Gillespie
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JOINTS OF THE BODY
Dr. Michael P. Gillespie
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SYNARTHROSES
A synarthrosis is a junction between two bones
that allows slight to essentially no movement.
 Synarthroidial joints can be classified as either
fibrous or cartilaginous based upon the dominant
type of connective tissue.

Dr. Michael P. Gillespie
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TYPES OF SYNARTHROSES

Fibrous joints
Dense connective tissue (high concentration of
collagen)
 Sutures of the skull
 Joints reinforced by an interosseous membrane
(distal tibiofibular joint).

Dr. Michael P. Gillespie

Cartilaginous joints
Flexible cartilage or hyaline cartilage
 Symphysis pubis
 Interbody joints of the spine
 Manubriosternal joint

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DIARTHROSES (SYNOVIAL JOINTS)
A diarthrosis is an articulation that allows
moderate to extensive motion.
 Possess a synovial fluid-filled cavity.
 Compose the majority of the joints within the
musculoskeletal system.

Dr. Michael P. Gillespie
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SEVEN ELEMENTS OF
DIARTHRODIAL JOINTS
Articular cartilage – covers the ends and other
articular surfaces of bones
 Joint capsule (articular capsule) – peripheral
curtain of connective tissue
 Synovial membrane – dcxf vcdx d cxdfv cxfefdsex
 Synovial fluid
 Ligaments

Dr. Michael P. Gillespie
Capsular ligaments
 Extracapsular ligaments

Blood vessels
 Sensory nerves

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ELEMENTS OF SYNOVIAL JOINTS
Dr. Michael P. Gillespie
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INTRA-ARTICULAR DISCS (MENISCI)
Intra-articular discs (meninsci) – pads of
fibrocartilage imposed between articular
surfaces.
 These pads increase congruency and improve
force dispersion.
 Examples of intra-articular discs






Tibiofemoral (knee)
Distal radio-ulnar
Sternoclavicular
Acromioclavicular
Temporomandibular
Apophyseal (variable)
Dr. Michael P. Gillespie

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PERIPHERAL LABRUM
A peripheral labrum of fibrocartilage extends
from the body rims of the glenoid fossa to the
shoulder and the acetabulum of the hip.
 These structures deepen the concave surface of
the joint.
 These structures support and thicken the
attachment of the joint capsule.

Dr. Michael P. Gillespie
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FAT PADS
Fat pads thicken the joint capsule, causing the
inner surface of the capsule to fill nonarticulating
joint spaces formed by incongruent bony
contours.
 They are prominent in the elbow and knee joints.
 Enlarged and inflamed fat pads can adversely
affect the biomechanics of the joint.

Dr. Michael P. Gillespie
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BURSAE
A bursa is an extension or outpouching of the
synovial membrane of a diarthroidial joint.
 Bursae are filled with synovial fluid and exists in
areas of potential stress.
 Bursae help to absorb force and protect
periarticular connective tissues, including bone.

Dr. Michael P. Gillespie
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SYNOVIAL PLICA
Synovial plicae (synovial folds, synovial
redundancies, or synovial fringes) are slack,
overlapped pleats of tissue composed of the
innermost layers of the joint capsule.
 They are found in joints with large capsular
surface area such as the knee and elbow.
 They increase the synovial surface area and
allow full joint motion without undue tension on
the synovial lining.
 Folds that are thickened or adhered due to
inflammation can alter the joint biomechanics.

Dr. Michael P. Gillespie
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STRUCTURAL CLASSIFICATION OF JOINTS
 Fibrous

Fibrous CT
Lack a synovial cavity
 Cartilaginous


Joints
Cartilage
Lack a synovial cavity
 Synovial
Dr. Michael P. Gillespie

Joints
Joints
Have a synovial cavity
 Dense irregular CT
 Often associated with accessory ligaments

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FUNCTIONAL CLASSIFICATION OF JOINTS

Synarthrosis (syn = together)

Amphiarthrosis (amphi = on both sides)


A slightly moveable joint
Diarthrosis (moveable joint)
A freely moveable joint
 Synovial joints

Dr. Michael P. Gillespie

Immovable joint
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FIBROUS JOINTS
Lacks a synovial cavity
 Little or no movement

Dr. Michael P. Gillespie
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FIBROUS JOINTS
 Sutures

Immovable
Synostosis – suture that is replaced by bone in
the adult
 Syndesmoses



Slightly moveable (amphiarthrosis)
Ligament
Interosseous membrane
Dr. Michael P. Gillespie

 Gomphoses

Dentoalveolar joint
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CARTILAGINOUS JOINTS
Lacks a synovial cavity
 Allows little or no movement
 Synchondroses


Epiphyseal plate
Symphyses
Pubic symphisis
 Intervertebral discs

Dr. Michael P. Gillespie

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SYNOVIAL JOINTS
Synovial (Joint) Cavity – space btwn. Bones
 Freely moveable
 The bones are covered by hyaline cartilage
 Contains the following:



Articular capsule
Synovial fluid
Accsessory ligaments and articular discs
Dr. Michael P. Gillespie

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CLASSIFICATION OF SYNOVIAL JOINTS
BASED ON MECHANICAL ANALOGY
Hinge joint
 Pivot joint
 Ellipsoid joint
 Ball-and-socket joint
 Plane joint
 Saddle joint
 Condyloid joint

Dr. Michael P. Gillespie
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HINGE JOINT

Primary Angular Motions

Mechanical Analogy


Door hinge
Anatomic Examples
Humero-ulnar joint
 Interphalangeal joint

Dr. Michael P. Gillespie

Flexion and extension only
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HINGE JOINT
Dr. Michael P. Gillespie
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PIVOT JOINT

Primary Angular Motions

Mechanical Analogy


Doorknob
Anatomic Examples
Dr. Michael P. Gillespie

Spinning of one member around a single axis of
rotation
Humeroradial joint
 Atlanto-axial joint

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PIVOT JOINT
Dr. Michael P. Gillespie
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ELLIPSOID JOINT

Primary Angular Motions

Mechanical Analogy


Flattened convex ellipsoid paired with a concave
trough
Dr. Michael P. Gillespie

Biplanar motion (flexion-extension and abductionadduction)
Anatomic Examples

Radiocarpal joint
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ELLIPSOID JOINT
Dr. Michael P. Gillespie
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BALL-AND-SOCKET JOINT

Primary Angular Motions

Mechanical Analogy


Spheric convex surface paired with a concave cup
Anatomic Examples
Dr. Michael P. Gillespie

Triplanar motion (flexion-extension, abductionadduction, and internal-external rotation)
Glenohumeral joint
 Coxofemoral (hip) joint

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BALL-AND-SOCKET JOINT
Dr. Michael P. Gillespie
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PLANE JOINT

Primary Angular Motions

Mechanical Analogy


Relatively flat surfaces apposing each other, like a
book on a table
Anatomic Examples
Dr. Michael P. Gillespie

Slide (translation) or combined slide and rotation
Carpometacarpal joints (digits II to IV)
 Intercarpal joints
 Intertarsal joints

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PLANE JOINT
Dr. Michael P. Gillespie
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SADDLE JOINT

Primary Angular Motions
Biplanar motion
 Spin between bones is possible, but may be limited by
interlocking nature of joint

Mechanical Analogy


Each member has a reciprocally curved concave and
convex surface oriented at right angles to the other,
like a horse rider and a saddle
Dr. Michael P. Gillespie

Anatomic Examples


Carpometarcarpal joint of the thumb
Sternoclavicular joint
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SADDLE JOINT
Dr. Michael P. Gillespie
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CONDYLOID JOINT

Primary Angular Motions
Biplanar motion
 Either flexion-extension and abduction-adduction, or
flexion-extension and axial rotation (internalexternal rotation)

Mechanical Analogy


Dr. Michael P. Gillespie

Mostly spheric convex surface that is enlarged in one
dimension like a knuckle; paired with a shallow
concave cup
Anatomic Examples
Metacarpophalangeal joint
 Tibiofemoral (knee) joint

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CONDYLOID JOINT
Dr. Michael P. Gillespie
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SIMPLIFYING THE CLASSIFICATION
OF SYNOVIAL JOINTS

Two articular forms based upon true movement
of the joint.

Essentially all synovial joints of the body with
the notable exception of planar joints can be
categorized under this scheme.
Dr. Michael P. Gillespie
Ovoid joint
 Saddle joint

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OVOID JOINT
An ovoid joint has paired mating surfaces that
are imperfectly spheric, or egg-shaped, with
adjacent parts possessing a changing surface
curvature.
 The articular surface of one bone is convex and of
the other is concave.
 Most joints of the body are of this variety.

Dr. Michael P. Gillespie
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SADDLE JOINT
A saddle joint consists of paired convex and
concave surfaces oriented at approximately 90
degrees to each other.
 Each member has a reciprocally curved concave
and convex surface oriented at right angles to the
other, like a horse rider and a saddle.

Dr. Michael P. Gillespie
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BASIC SHAPES OF JOINT SURFACES
Dr. Michael P. Gillespie
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Dr. Michael P. Gillespie
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BIOLOGICAL MATERIALS OF
PERIARTICULAR CONNECTIVE
TISSUES

Fibrous Proteins

Ground Substance
Glycosaminoglycans
 Water
 Solutes


Dr. Michael P. Gillespie

Collagen (type I and II)
Cells
Fibroblasts
 Chondrocytes

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TYPES OF COLLAGEN IN
PERIARTICULAR CONNECTIVE
TISSUES

Type I
Thick, rugged fibers that elongate when stretched
 Present in ligaments, tendons, fascia, and fibrous
joint capsules

Type II
Thinner fibers than type I
 Provide a framework for maintaining the general
shape and consistency of structures, such as hyaline
cartilage

Dr. Michael P. Gillespie

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TYPES OF MOVEMENTS AT SYNOVIAL
JOINTS
 Gliding
Simple back and forth movement, limited in
range, planar joints
 Angular

Movements
Increase or decrease in the angle btwn. bones
Dr. Michael P. Gillespie

 Rotation

Bone revolves around a longitudinal axis
 Special
Movements
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ANGULAR MOVEMENTS
Flexion, extension, lateral flexion,
hyperextension
 Abduction, adduction, and circumduction

Dr. Michael P. Gillespie
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ROTATION
Medial (internal) rotation
 Lateral (external) rotation

Dr. Michael P. Gillespie
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SPECIAL MOVEMENTS
Elevation
 Depression
 Protraction
 Retraction
 Inversion

Dr. Michael P. Gillespie
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SPECIAL MOVEMENTS
Eversion
 Dorsiflexion
 Plantar flexion
 Supination
 Pronation
 Opposition

Dr. Michael P. Gillespie
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DISLOCATION

Luxation – displacement of a bone from a joint

Subluxation

Incomplete dislocation
Dr. Michael P. Gillespie

Causes tearing or ligaments, tendons, and articular
capsules
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ARTHROSCOPY
Observaion of the interior of a joint
 Utilizes a lighted, pencil-thin instrument
 Assists in surgery and assessment of the joint
space

Dr. Michael P. Gillespie
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SPRAIN & STRAIN

The ankle joint is the most often sprained.
 The lumbar spine is another prominent location of
sprain.


Dr. Michael P. Gillespie
Sprain – a forcible wrenching or twisting of the
joint that stretches or tears its ligaments, but
does not dislocate the bones.
Strain – a stretched or partially torn muscle.
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BURSAE & TENDON SHEATHS

Bursae


Tendon sheaths
Tubelike bursae that wrap around tendons
 Occurs where tendons pass through synovial cavities
 Reduce friction

Dr. Michael P. Gillespie

Saclike structures
Reduce friction in some synovial joints
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BURSITIS
 An

Dr. Michael P. Gillespie
acute or chronic inflammation of a
bursa
 Caused by trauma or infection
 Repeated excessive exertion
 Symptoms
Pain, swelling, inflammation & limited
movement
 Treatment

Oral anti-inflammatory agents (herbal, O.T.C.
And prescription), corticosteroid injections
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Dr. Michael P. Gillespie
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ROTATOR CUFF INJURY
Supraspinatous
 Infraspinatous
 Teres Minor
 Subscapularis
 Common injury among pitchers and volleyball
players due to excessive circumduction

Dr. Michael P. Gillespie
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SEPARATED SHOULDER
Injury of the acromioclavicular joint
 Due to forceful trauma such as when the
shoulder strikes the ground in a fall

Dr. Michael P. Gillespie
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TENNIS ELBOW
Lateral epicondylitis
 Little-league elbow

Dr. Michael P. Gillespie
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GOLFER’S ELBOW

Medial Epicondylitis
Dr. Michael P. Gillespie
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DISLOCATION OF THE RADIAL HEAD
The most common upper limb dislocation in
children
 Occurs with a strong pull to the forearm while it
is extended and supinated
 Swinging a child around with outstretched arms

Dr. Michael P. Gillespie
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SWOLLEN KNEE
Immediate swelling is due to blood loss
 Delayed swelling is due to excessive production of
synovial fluid “water on the knee”

Dr. Michael P. Gillespie
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DISLOCATED KNEE
Displacement of the tibia relative to the femur
 Most commonly dislocates anteriorly

Dr. Michael P. Gillespie
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RHEUMATISM

Dr. Michael P. Gillespie
Any painful disorder of the supporting structures
of the body – bones, ligaments, tendons, or
muscles – that is not caused by infection or
injury.
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ARTHRITIS

A form of rheumatism in which the joints are
swollen, stiff, and painful.
Dr. Michael P. Gillespie
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TYPES OF ARTHRITIS

Rheumatoid arthritis (RA)

Osteoarthritis (OA)


Degenerative joint disease
Gouty arthritis

A person with gout produces excessive uric acid or is
unable to excrete it properly
Dr. Michael P. Gillespie

Autoimmune disease – the body attacks its own
tissues
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LYME DISEASE
First reported in Lyme, CT
 Bacteria transported by deer ticks
 The rash often resembles a bull’s eye target,
although some people never develop a rash
 Symptoms

Joint stiffness, fever, chills, headache, stiff neck,
nausea
Dr. Michael P. Gillespie

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TERMINOLOGY
Arthralgia – pain in a joint
 Bursectomy – removal of a bursa
 Chondritis – inflammation of cartilage
 Synovitis – inflammation of a synovial membrane
in a joint

Dr. Michael P. Gillespie
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