Download Synovial joints

Articulations
BIO 238
Copyright 2010, John Wiley & Sons, Inc.
Joint Classification
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A joint is where two bones meet*
Joints may be classified by structure or by
function
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The structural classification of joints:
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Fibrous joints (bones held together by dense
collagen fibers)
Cartilaginous joints (bones held together by
cartilage)
Synovial joints (bones held together by ligaments)
Joint Classification
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The functional classification of joints:
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Synarthrosis (an immovable joint)
Amphiarthrosis (a slightly movable joint)
Diarthrosis (a freely movable joint)
Copyright 2010, John Wiley & Sons, Inc.
Joints (Fibrous Joints)
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Lack a synovial cavity
The articulating bones are held very closely together by dense
irregular connective tissue
Fibrous joints permit little or no movement
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3 types of fibrous joints:
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Sutures
Syndesmoses
Gomphoses
Copyright 2010, John Wiley & Sons, Inc.
Joints (Fibrous Joints)
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Sutures
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Syndesmoses
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Immovable joint
Occur only between the skull bones
Permits slight movement
Interosseous membrane
Between the tibia and fibula in the leg
Gomphoses
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Immovable joint
Joint in which a cone-shaped peg fits
into a cup shaped socket
Articulations of the teeth with the
sockets of the maxillae and mandible
Syndesmoses
Copyright 2010, John Wiley & Sons, Inc.
Joints (Cartilaginous Joints)
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Lack a synovial cavity
Allow little or no movement
The joint is tightly connected by cartilage
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2 types of cartilaginous joints:
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Synchondroses
Symphyses
Cartilaginous Joints
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Synchondroses
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The Connecting tissue is hyaline cartilage
Found in Epiphyseal (growth) plate in bones
Symphyses
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Slightly movable joint
Ends of the articulating bones are covered with hyaline cartilage,
but a disc of fibrocartilage connects the bones
Pubic Symphysis is between the anterior surfaces of the hip
bones
Also found in the intervertebral joints between the vertebrae
Synchondrosis
Copyright 2010, John Wiley & Sons, Inc.
Symphysis
Copyright 2010, John Wiley & Sons, Inc.
Synovial Joints
Components of a synovial joint:
 Ligaments hold bones together for extra
support
 Synovial cavity a space allowing a joint to be
freely movable
 Articular Capsule
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A sleeve-like capsule enclosing the synovial cavity
The articular capsule is composed of 2 layers:
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an outer fibrous capsule
an inner synovial membrane
Synovial Fluid
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Secreted by the synovial membrane lining the capsule
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Functions to reduce friction by:
lubricating
the joint
absorbing
shock
supplying
oxygen and nutrients to the cartilage
removing
carbon dioxide and metabolic wastes from the cartilage
Synovial Joints
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Accessory Ligaments and Articular Discs
May be present in some joints for example the knee
joint
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Collateral ligaments of the knee joint (Medial and Lateral)
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Cruciate ligaments of the knee joint (Anterior and Posterior)
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Menisci ( C shaped and O shaped)
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Pads of cartilage lie between the articular surfaces of the bones
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Allows bones of different shapes to fit together more tightly
Copyright 2010, John Wiley & Sons, Inc.
Nerve and Blood Supply
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Nerve and Blood Supply
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Nerve endings convey information about pain from the
joint to the spinal cord and brain
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Nerve endings respond to the degree of movement
and stretch at a joint
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Arterial branches from several different arteries merge
around a joint before penetrating the articular capsule
Synovial Joints
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Bursae and Tendon Sheaths
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Bursae
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Sac-like structures containing fluid similar to
synovial fluid
Located between tendons, ligaments and bones
Cushion the movement of these body parts
Tendon sheaths
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Wrap around tendons
Reduce friction at joints
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Specific terminology is used to designate the movements
that occur at joints
Movements are grouped into four main categories:
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1) Gliding
2) Angular movements
3) Rotation
4) Special movements
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Gliding
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Simple movement back-and-forth and from side-to-side
There is no significant alteration of the angle between the bones
Limited in range
Intercarpal joints
Angular Movements
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Increase or a decrease the angle between articulating bones
Angular movements include:
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Flexion
Extension
Lateral flexion (side bending)
Hyperextension
Abduction
Adduction
Circumduction
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Flexion
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Extension
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Continuation of extension beyond the normal extension
Bending the trunk backward
Abduction
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Movement of the trunk sideways to the right or left at the waist
Hyperextension
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Increases the angle between articulating bones
Flexion and extension are opposite movements
Lateral flexion
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Decreases the angle between articulating bones
Bending the trunk forward
Movement of a bone away from the midline
Moving the humerus laterally at the shoulder joint
Adduction
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Movement of a bone toward the midline
Movement that returns body parts to normal position from abduction
Copyright 2010, John Wiley & Sons, Inc.
Types of Movements at Synovial Joints
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Circumduction
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Movement of a body part in a circle
Moving the humerus in a circle at the shoulder joint
Rotation
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A bone revolves around its own longitudinal axis
Turning the head from side to side as when you shake your head “no”
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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Special Movements
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Elevation
Depression
Protraction
Retraction
Inversion
Eversion
Dorsiflexion
Plantar flexion
Supination
Pronation
Opposition
Copyright 2010, John Wiley & Sons, Inc.
Types of Synovial Joints
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Synovial joints are classified based on type of
movement
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Planar (Plane Joints)
Hinge
Pivot
Condyloid
Saddle
Ball-and-socket
Copyright 2010, John Wiley & Sons, Inc.
Types of Synovial Joints
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Planar Joints
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Pivot Joints
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Allow for rotation
Found in the radioulnar and alanto-axial joints
Hinge Joints
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Primarily permit back-and-forth and side-to-side movements
Intercarpal joints
Produce an opening and closing motion like that of a hinged door
Permit only flexion and extension
Knee and elbow
Condyloid
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Oval-shaped condyle fits into an ellipsoidal socket
Joint between carpals and wrist
Copyright 2010, John Wiley & Sons, Inc.
Types of Synovial Joints
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Saddle
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Two saddle shaped bones fitting together
Found in joint between thumb metacarpal and wrist carpal.
Ball and socket
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Provides the greatest ROM
Found in the hip and shoulder joints
Copyright 2010, John Wiley & Sons, Inc.
Temporomandibular Joint
Copyright 2010, John Wiley & Sons, Inc.
Temporomandibular Joint
Copyright 2010, John Wiley & Sons, Inc.
Shoulder Joint
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Ball-and-socket joint formed by the head of the
humerus and the scapula
More freedom of movement than any other joint of the
body
Copyright 2010, John Wiley & Sons, Inc.
Elbow Joint
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Hinge joint formed by the humerus, the ulna, and the
radius
Copyright 2010, John Wiley & Sons, Inc.
Hip Joint
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Ball-and-socket joint formed by the femur and the hip
bone
Copyright 2010, John Wiley & Sons, Inc.
Knee Joint
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Largest and most
complex joint of
the body
Modified hinge
joint
Copyright 2010, John Wiley & Sons, Inc.
Range of Motion (ROM)
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Refers to the range, measured in degrees of a circle,
through which the bones of a joint can be moved
Measured in a scale up to 360 degrees
Measured using a goniometer
Range of motion allows us to measure a persons
movements and compare them to an average
person’s range to determine if they have an injury or
impairment
Copyright 2010, John Wiley & Sons, Inc.
Factors that contribute to keeping the articular
surfaces in contact and affect range of motion
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Structure or shape of the articulating bones
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Strength and tension of the joint ligaments
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Arrangement and tension of the muscles
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Contact of soft parts
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Hormones
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Disuse
Copyright 2010, John Wiley & Sons, Inc.
Aging and Joints
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May result in decreased production of synovial fluid
The articular cartilage becomes thinner
Discs and muscle may have decrease in water content
Ligaments shorten and lose some of their flexibility
Osteoarthritis increases with age
Stretching, aerobic exercises and strength training has shown
to be helpful in minimizing the effects of aging
Exercise helps to maintain the effective functioning of
ligaments, tendons, muscles, synovial fluid, and articular
cartilage by increasing nutrition to the joint
Furthermore weight bearing stimulates the joint to produce
more bone which prevents osteoarthritis
Copyright 2010, John Wiley & Sons, Inc.
Joint Diseases
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Osteoarthritis
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The most common type of arthritis
A degenerative disease that results from aging
and wear.
The articular cartilages gradually disintegrate,
which causes pain and restricts movement.
Copyright 2010, John Wiley & Sons, Inc.
Joint Diseases
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Rheumatoid Arthritis
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A chronic autoimmune condition
Often the most painful and crippling type of
arthritis
The synovial membrane thickens, synovial fluid
accumulates causing swelling, and articular
cartilages are destroyed.
The joint is invaded by fibrous connective tissue
that ultimately ossifies, making the joint
immovable.
Copyright 2010, John Wiley & Sons, Inc.
Joint Diseases
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Dislocation- the displacement of bones
forming a joint.
Subluxation- a slight dislocation
Sprains result from tearing or excessive
stretching of the ligaments and tendons at a
joint without a dislocation.
Bursitis- the inflammation of a bursa. It may
be caused by excessive use or injury
Copyright 2010, John Wiley & Sons, Inc.
Joint Diseases
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Herniated disc is a
condition in which the
nucleus pulposis of
an intervertebral disc
protrudes beyond the
edge of a vertebra.
The protruding disk
may place pressure
on a spinal nerve and
cause considerable
pain.
Copyright 2010, John Wiley & Sons, Inc.
Arthrocentesis
Treatment for Damaged Joints
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Arthroplasty
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Hip Replacements
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Joints may be replaced surgically with artificial joints
Most commonly replaced are the hips, knees, and shoulders
Partial hip replacements involve only the femur
Total hip replacements involve both the acetabulum and head of
the femur
Knee Replacements
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Actually a resurfacing of cartilage and may be partial or total
Potential complications of arthroplasty include infection, blood
clots, loosening or dislocation of the replacement components,
and nerve injury
Copyright 2010, John Wiley & Sons, Inc.
Hip Joint Replacement
Copyright 2010, John Wiley & Sons, Inc.
Healthcare Applications:
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For therapists range of motion (ROM) will be
an important tool to determine a clients
limitations and a motivating factor for
improvement in musculoskeletal injuries.
During the acute stages of many of these
conditions, massage is contraindicated.
However it can be used in later stages to
ease muscle tension, reduce pain, and
maintain flexibility.