1. Chapter 9
Articulations

2. Articulations Point of contact between bones.
Joint- mostly very movable but some are immovable or only allow limited motions.
Movable joints allow complex, highly coordinated movements.

3. Classifications
Structural classification- joints are named according to:
Type of connective tissue
Presence of fluid filled joint capsules
Functional classification-
Synarthroses- immovable
Amphiarthroses- slightly movable
Diarthroses- freely movable

4. Fibrous Joints Synarthroses
Bones of joints fit together closely, allowing little or no movement.
Syndesmoses- joints in which ligaments connect two bones.
Sutures- found only in skull; toothlike projections from adjacent bones interlock with each other.
Gomphoses- between root of a tooth and the alveolar process of mandible and maxilla.

5. Cartilaginous joints
Bones of joints are joined together by hyaline cartilage of fibrocartilage; allow very little motion.

6. Synovial joints Freely movable joints Structures: Joint capsule
Synovial membrane
Articular cartilage
Joint cavity
Menisci
Ligaments
Bursae

7. Types of Synovial Joints
Uniaxial joints
Hinge joints- knee, elbow
Pivot joints- neck/vertebrae, radius
Biaxial joints
Saddle joints- thumbs
Condyloid joints- hips, shoulders

8. Types of Synovial Joints
Multiaxial joints
Ball and socket joint- shoulder, femur
Gliding joint- wrists, vertebrae

9. Humeroscapular Joint Shoulder joint
Most mobile joint because of glenoid cavity
Glenoid labrum

10. Elbow Joint Humeroradius joint Humeroulnar joint
Both components of elbow joint surrounded by single joint capsule and stabilized by collateral ligaments.

11. Hip Joint
Stable joint

12. Knee Joint
Largest and one of the most complex and most frequently injured joints.
Tibiofemoral joint- supported by joint capsule, cartilage, ligaments, and tendons.
Permits flexion and extension

13. Ankle Joint Hinge type of synovial joint
Articulation between lower ends of tibia and fibula and upper part of talus.
Joint is “mortise” or wedge-shaped.
Lateral malleolus lower than medial.

14. Measuring Range of Motion
Range of motion (ROM) assessment used to determine extent of joint injury.
ROM can be measured actively or passively; results of both by instrument called goniometer.

15. Angular Movement
Change in the size of angle between articulating bones.
Flexion- decreases angle between bones; bends or folds one part on another.
Extension- increases angle between two bones.
Hyperextension- extension between bones of a joint that is greater than normal.
Plantar flexion- increases angle between top of foot and front of leg.

16. Angular Movement
Dorsi flexion- decreases angle between top of foot and front of leg.
Abduction- moves part away from median plan of body.
Adduction- moves a part toward median plane of body.

17. Circular Movements Rotation- pivoting a bone on its own axis.
Circumduction- moves a part so that its distal end moves in a circle.
Supination- turns the hand palm side-up.
Pronation- turns the hand palm side-down.

18. Gliding Movements
Simplest of all movements; articular surface of one bone moves over articular surface of another without any angular or circular movement.

19. Special Movements Inversion- turning sole of foot inward.
Eversion- turning sole outward.
Protraction- moves a part forward.
Retraction- moves part backward.
Elevation- moves part up.
Depression- lowers a part.