GENERAL OBJECTIVE
• At the end of the lecture/discussion,
students should gain knowledge on Joints
SPECIFIC OBJECTIVES
At the end of the lecture/discussion, students
should be able to;
• Define joint
• Describe the joins classifications , types and
movement
INTRODUCTION
• Joint, in anatomy, a structure that separates
two or more adjacent elements of the skeletal
system. Depending on the type of joint, such
separated elements may or may not move on
one another.
DEFINITION
• A Joint is the site at which two or more bones
articulate or come together. Some joints have
no movement (fibrous), some only slight
movement (cartilaginous) and some are freely
movable (synovial).
CLASSIFICATIONS AND MOVEMENTS
• Bones are too rigid to bend without being damaged,
fortunately flexible connective tissues form joints. Joints
that hold bones permit, in most cases some degree of
movement. A joint is also called an articulation or
arthrosis, which is a point of contact between two bones,
between bones and cartilage or between bone and teeth.
CLASSIFICATIONS AND MOVEMENTS Cont...
• When we say one bone articulate with another bone, we
mean that the bone forms a joint. We appreciate the
beauty and importance of joints when we have a cast
(POP) over our knee joint which makes walking difficult or
a splint on one of our fingers that limits our ability
tomanipulate small objects.
CLASSIFICATIONS AND MOVEMENTS Cont...
Criteria for Classification of Joints
• Gerard J. Tortora et al. (2006) classified joints according to:
i. Structure criteria
ii. Anatomical characteristic and function
iii. Type of movement they permit.
Let us consider each classification in further detail.
CLASSIFICATIONS AND MOVEMENTS Cont...
1. Structural Criteria
• The structural classification of joints is based on two
criteria. The first being the presence of or absence of a
space between the articulating bones (synovial cavity)
and second being the type of connective tissue that binds
the bones together.
• They include:
CLASSIFICATIONS AND MOVEMENTS Cont...
• Fibrous or Fixed Joints
These are joints with no synovial cavity and the
bones are held together by fibrous connective
tissue that is rich in collagen fibres and they
don’t make any movement. Examples are:
CLASSIFICATIONS AND MOVEMENTS Cont...
• Joints between bones of the skull
(sutures)
• Joints between the teeth and the maxilla
and mandible
LASSIFICATIONS AND MOVEMENTS Cont...
Synovial Joints (Free Movable Joints)
• These are joints without synovial cavity, the bones are
held together by cartilage (fibrocartilage) between the
ends of the bones that form the joint which allows for very
slight movement where the pad of cartilage is
compressed. Examples include:
CLASSIFICATIONS AND MOVEMENTS Cont...
Synovial Joints (Free Movable Joints)
• These are joints that have synovial cavity and fluid.
They are held together by a dense irregular
connective tissue of an articular capsule and often by
accessory ligament. Examples of synovial joints
include the following:
CLASSIFICATIONS AND MOVEMENTS Cont...
• Ball and socket joint
• Hinge joint
• Grinding joint
• Pivot joint
• Condyloid joint
• Saddle joint
• Condyloid joint
CLASSIFICATIONS AND MOVEMENTS Cont...
Anatomical Characteristic and Function Criteria
• The anatomical characteristic and function classification
of joints relates to the degree of movement the joint
permits. They include the following: Synarthrosis are
joints which doesn’t permit any movement at all
• Amphiarthrosis are joint which permits slight movement
• Diarthrosis are joints which have a variety of shapes
and permit several different
• types of movement.
CLASSIFICATIONS AND MOVEMENTS Cont...
Type of Movement They Permit Criteria (Free Movable
Joint)
• These are joints which are classified according to the
range of movement possible at a joint or to the shape of
the articulating parts of the bones involved (also called
synovial joints). They include the following:
CLASSIFICATIONS AND MOVEMENTS Cont...
• Ball and socket joint
• Hinge joint
• Gliding joint
• Pivot joint
• Condyloid and saddle joint
CLASSIFICATIONS AND MOVEMENTS Cont...
• Ball and socket joint: is formed by the head
or ball of one bone which articulates with a
socket of another. The shape of the bone
allows for a wide range of movement including
the
• following:
CLASSIFICATIONS AND MOVEMENTS Cont...
• Flexion
• Extension
• Adduction
• Abduction
• Rotation
• Circumduction.
Examples of ball and socket joint are the shoulder and hip
joints,
CLASSIFICATIONS AND MOVEMENTS Cont...
• Hinge joints: these are types of synovial joint which
allow the movements of flexion and extension only.
Examples of hinge joint include the following:
• Elbow
• Knee
• Ankle
• Atlas and the occipital bone
• Interphalangeal joints of the fingers and toes.
CLASSIFICATIONS AND MOVEMENTS Cont...
Gliding joints: these are joints whose articular surfaces glide over each
other. Examples of
• grinding joints include the following: Sternoclavicular joints,
• Acromioclavicular joints
• joints between the carpal bones
• Those between the tarsal bones.
CLASSIFICATIONS AND MOVEMENTS Cont...
Pivot joints: these are joints whose movement is round one
axis (rotation). They include:
• Proximal and distal radio ulnar joints
• Joint between the atlas and the odontoid process of the
axis.
CLASSIFICATIONS AND MOVEMENTS Cont...
Condyloid and saddle joints: these are joints whose
movements take place round two axes,
permitting the following movements:
• Flexion,
• Extension,
• Abduction,
• Adduction
• Circumduction,
CLASSIFICATIONS AND MOVEMENTS Cont...
Examples of condyloid and saddle joint include:
• The wrist joint,
• Temporomandibular joint
• Metacarpo-phalangeal joint
• Metatarsophalangeal joints
CLASSIFICATIONS AND MOVEMENTS Cont...
The Synovial Joint
• Can you remember how we defined a synovial joint? We
said that it is a joint that have synovial cavity and fluid. In
this sub-section we shall look at the movements possible at
the synovial joint, its characteristics, functions and other
related structures.
CLASSIFICATIONS AND MOVEMENTS Cont...
Movements Possible at Synovial Joint
• The following movements are possible at the
synovial joint:
• Flexion: that is bending, usually forward but
occasionally backward, e.g. knee joint
• Extension: straightening or bending backward
• Abduction: the movement away from the midline
of the body
CLASSIFICATIONS AND MOVEMENTS Cont...
• Adduction: the movement towards the midline of the
body
• Circumduction: the combination of flexion, extension,
abduction and adduction
• Rotation: the movement round the long axis of a bone
• Pronation: the turning the palm of the hand down
• Supination: the turning the palm of the hand up
• Inversion: the turning the sole of the foot inward
• Eversion: the turning the sole of the foot outwards
That brings us to the end of discussion on
joints. We have discussed their structure,
anatomical characteristics and function and the
type of movements they permit.
REFERENCES
• Pacifici M, Koyama E, Iwamoto M. Mechanisms of synovial joint
and articular cartilage formation: recent advances, but many
lingering mysteries. Birth Defects Res C Embryo Today. 2005
Sep;75(3):237-48.
• Chijimatsu R, Saito T. Mechanisms of synovial joint and articular
cartilage development. Cell Mol Life Sci. 2019 Oct;76(20):3939-
3952.
• Hébert-Blouin MN, Tubbs RS, Carmichael SW, Spinner RJ.
Hilton's law revisited. Clin Anat. 2014 May;27(4):548-55.
• Eisová S, Naňka O, Velemínský P, Bruner E. Craniovascular
traits and braincase morphology in craniosynostotic human