Joints can be classified based on their structure and movement. The main types are fibrous, cartilaginous, and synovial joints. Fibrous joints like sutures are generally immovable. Cartilaginous joints like symphysis allow slight movement. Synovial joints are freely movable and include ball-and-socket joints like the shoulder and hip, hinge joints like the elbow and knee, and gliding joints. Joints also have specific movements like flexion, extension, abduction, adduction, rotation, and circumduction.

1. Joints
SCK
9-1

2. Definition of Joint
the point of connection between two bones or
elements of a skeleton (especially if it allows
motion)
9-2

3. Structural Classification of Joints
• Fibrous joints
Generally immoveable
• Cartilaginous joints
Immovable or slightly moveable
• Synovial joints
Freely moveable
9-3

4. Joints and their Classification
• Classified by freedom of movement
synarthrosis ( little no movement)
amphiarthrosis (slightly movable)
diarthrosis (freely movable)
• Classified how adjacent bones are joined
– fibrous, cartilaginous, bony or synovial
9-4

5. Fibrous Joints (Synarthrosis)
• Collagen fibers span ( ‫پھیال‬
‫)ہوا‬the space between bones
– sutures,
– gomphoses(slight movable
teeth)
syndesmoses(immovable
joint between the fibula and
tibia at the ankle)
9-5

6. Fibrous Joint -- Sutures
• Immovable fibrous joints
– bind skull bones together
• Serrate - interlocking lines
– coronal, sagittal and
lambdoid sutures
• Lap - overlapping beveled
edges
– temporal and parietal
bones
• Plane - straight,
nonoverlapping edges
– palatine processes of the
maxillae 9-6

7. Types of Sutures
9-7

8. Fibrous Joint -- Gomphoses
• Attachment of a tooth to its
socket
• Held in place by fibrous
periodontal ligament
– collagen fibers attach
tooth to jawbone
• Some movement while
chewing
9-8

9. Fibrous Joint –Syndesmosis
• Two bones bound
by ligament only
– interosseus membrane(is a thick dense fibrous sheet of
connective tissue that spans(‫ہوا‬ ‫)پھیال‬ the space between
two bones forming a type of syndesmosis joint)
• Most movable of fibrous joints
• Interosseus membranes unite radius to ulna and
tibia to fibula 9-9

10. Cartilaginous Joint -- Synchondrosis
• Bones are joined by hyaline
cartilage
– rib attachment to sternum
– epiphyseal plate in children
binds epiphysis and diaphysis
9-10

11. Cartilaginous Joint -- Symphysis
• 2 bones joined by
fibrocartilage
– pubic symphysis and
intervertebral discs
• Only slight amount
of movement is
possible
9-11

12. The Synovial Joint
Figure 5.28

13. Synovial Joint
 Joint in which two bones are separated by a space called a
joint cavity
 Most are freely movable
9-13

14. Features of Synovial Joints
• Articular cartilage (hyaline cartilage) covers
the ends of bones
• Joint surfaces are enclosed by a fibrous
articular capsule
• Have a joint cavity filled with synovial fluid
• Ligaments reinforce the joint

15. General Anatomy
• Articular capsule encloses joint cavity
– continuous with periosteum
– lined by synovial membrane
• Synovial fluid = slippery fluid; feeds cartilages
• Articular cartilage = hyaline cartilage covering the joint surfaces
• Articular discs and menisci
– jaw, wrist, sternoclavicular and knee joints
– absorbs shock, guides bone movements and distributes forces
• Tendon attaches b to bone
• Ligament attaches m to bone
9-15

16. What is a Bursar?
 is a small fluid-filled sac lined
by synovial membrane with a
inner capillary layer of slimy
fluid (similar to that of an egg
white).
 It provides a cushion
between bones and tendons
and/or muscles around a
joint. This helps to reduce any
friction between the bones
and allows free movement.
 Bursae are filled with
synovial fluid and are found
around almost every major
joint of the body; when they
become inflamed, the
condition is called bursitis. 9-16

17. Knee Joint – Sagittal Section
9-17

18. Axes of Rotation
• Shoulder joint has 3 degrees of freedom =
multiaxial joint
• Other joints – monoaxial or biaxial 9-18

19. Types of Synovial Joints Based on
Shape
9-19
Figure 5.29a–c

20. Types of Synovial Joints Based on
Shape
9-20
Figure 5.29d–f

21. Condyloid (ellipsoid) Joints
• Oval convex surface on one bone fits into a
similarly shaped depression on the next
– radiocarpal joint of the wrist
– metacarpophalangeal joints at the bases of the
fingers
• Biaxial joints
9-21

22. Gliding Joints (Also called Plane Joints)
• Flat articular surfaces in which bones slide
over each other
• Limited monoaxial joint
• Considered amphiarthroses
9-22

23. 9-23

24. Hinge Joints
• One bone with convex
surface that fits into a
concave depression on
other bone
– ulna and humerus at elbow
joint
– femur and tibia at knee joint
– finger and toe joints
• Monoaxial joint
9-24

25. Hinge Joint
9-25

26. Ball-and-Socket Joints
• Smooth hemispherical head fits within a
cuplike depression
– head of humerus into glenoid cavity of scapula
– head of femur into acetabulum of hip bone
• Multiaxial joint
9-26

27. Ball in Socket Joint
9-27

28. Pivot Joints
• One bone has a projection that fits into a ringlike
ligament of another
• First bone rotates on its longitudinal axis relative
to the other
– atlantoaxial joint (dens and atlas)
– proximal radioulnar joint allows the radius during
pronation and supination
9-28

29. Pivot Joint
9-29

30. Saddle Joints
 Each articular surface is
shaped like a saddle,
concave in one direction
and convex in the other
◦ trapeziometacarpal joint at the
base of the thumb
 Biaxial joint
◦ more movable than a
condyloid or hinge joint
forming the primate opposable
thumb
9-30

31. Flexion, Extension and Hyperextension
• Flexion decreases the
angle of a joint
• Extension straightens and
returns to the anatomical
position
• Hyperextension =
extension beyond 180
degrees
9-31

32. Flexion, Extension and Hyperextension
9-32

33. Abduction and Adduction
• Abduction is movement of a part away from the midline
– hyperabduction – raise arm over back or front of head
• Adduction is movement towards the midline
– hyperadduction – crossing fingers
9-33

34. Elevation and Depression
• Elevation is a movement that raises a bone vertically
– mandibles are elevated during biting and clavicles during a
shrug
• Depression is lowering the mandible or the shoulders
9-34

35. Protraction and Retraction
• Protraction = movement
anteriorly on horizontal
plane
– thrusting the jaw forward,
shoulders or pelvis forward
• Retraction is movement
posteriorly
9-35

36. Circumduction
• Movement in which one end of
an appendage remains
stationary while the other end
makes a circular motion
• Sequence of flexion, abduction,
extension and adduction
movements
– baseball player winding up for a
pitch
9-36

37. Rotation
• Movement on
longitudinal axis
– rotation of trunk,
thigh, head or arm
• Medial rotation
turns the bone
inwards
• Lateral rotation turns
the bone outwards
9-37

38. Supination and Pronation
 In the forearm and foot
 Supination
◦ rotation of forearm so that the palm
faces forward
◦ inversion and abduction of foot
(raising the medial edge of the foot)
 Pronation
◦ rotation of forearm so the palm faces
to the rear
◦ eversion and abduction of foot
(raising the lateral edge of the foot)
9-38

39. Movements of Head and Trunk
• Flexion, hyperextension and lateral flexion of vertebral
column 9-39

40. Rotation of Trunk and Head
• Right rotation of trunk; rotation of head
9-40

41. Movements of Mandible
 Lateral excursion = sideways movement
 Medial excursion = movement back to the midline
◦ side-to-side grinding during chewing
 Protraction – retraction of mandible
9-41

42. Movement of Hand and Digits
• Radial and ulnar
flexion
• Abduction of fingers
and thumb
• Opposition is
movement of the
thumb to approach or
touch the fingertips
• Reposition is
movement back to the
anatomical position
9-42

43. Movements of the Foot
 Dorsiflexion is raising of the toes as when you swing the foot
forward to take a step (heel strike)
 Plantarflexion is extension of the foot so that the toes point
downward as in standing on tiptoe
 Inversion is a movement in which the soles are turned medially
 Eversion is a turning of the soles to face laterally
9-43