The Articular System: Joints and Their Movements

2. 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