2. The Articular System Joints
Chapter 8
The Articular System
Joints

3. Introduction Articulation: union between two or more bones
Can be mobile or immobile
Examples
skull bones
Knee or elbow joint

4. The Classification of Joints: Structure and Function

5. Introduction Joints are classified into three major groups based on:
Degree of movement allowed (function)
Type of material holding bones together (structure)
1-synarthroses
2- Amphiarthroses
3- Diarthroses or synovial joints

6. Diarthroses or Synovial Joints (cont’d.)

7. Movements at Synovial Joints

8. Movements at Synovial Joints (cont’d.)
Flexion/extension
Hyperextension: abnormal extension
Dorsiflexion/plantar flexion
Abduction/adduction
Rotation
Circumduction

9. Movements at Synovial Joints (cont’d.)
Supination/pronation
Eversion/inversion
Protraction/retraction
Opposition/reposition

11. Flexion and extension
Flexion : The act of bending or decreasing the angle between bones.
Extension: The act of increasing the angle between bones and is the opposite of flexion.

12. Hyperextension
Hyperextension : It increases the joint angle beyond the anatomic position.

13. Abduction and adduction
Abduction: Is moving the bones away from the midline of the body.
Adduction: Is moving the bone toward the midline of the body.

14. Rotation and circumduction
Rotation: Is the act of moving the bone around a central axis.
Circumduction: Is moving the bone in such a way that the end of the bone describe the circle in the air and the sides of the bone describe a cone in the air.

15. Supination and pronation
Supination: Is moving the bones of the forearm so that the radius and ulna are in parallel.
Pronation :Is moving the bones of the forearm so that the radius and ulna are not parallel.

16. Eversion and inversion
Eversion : Is the moving the sole of the foot outward at the ankle.
Inversion: Is moving the sole of the foot inward at the ankle.

18. The Six Types of Diarthroses or Synovial Joints

19. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Ball-and-socket
Widest range of movement
Movement can occur in all planes and directions
Shoulder
Hip

20. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Ball-and-socket

21. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Hinge
Convex surface fits into concave surface
Flexion and extension only
Knee
Elbow

22. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Hinge

23. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Pivot
Rotation in one plane
Atlas and axis (cervical spine)
Rotation of the head

24. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Pivot

25. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Condyloid (ellipsoidal)
Oval-shaped condyle fits into elliptical cavity
Motion in two planes at right angles
Radius and carpal bones

26. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Condyloid (ellipsoidal)

27. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Saddle
Motion in two planes at right angles
Permits opposition of the thumb

28. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Saddle

29. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Gliding
Gliding motion
Intervertebral joints in spine

30. The Six Types of Diarthroses or Synovial Joints (cont’d.)
Gliding