1. Part 2: Support & Movement
Joints
Part 2: Support & Movement

2. Joints
Joints or Articulations: Locations were bones join together that allow for some degree of movement.
Arthrology: The scientific study of Joints!
Most important joints for this test: Knee and Shoulder
Classification: Either by structure or range of movement allowed.

4. Structural Classifications
Synovial Joints: The most important type; found throughout the body and named for their synovial cavity that is lubricated by the synovial fluid.
Freely movable joints
Bones joined together by dense irregular connective tissue within the fibrous joint capsule
Primary examples: Elbow, knee, hip, ankle

6. Structural Classifications
Fibrous Joints: Joints where the bones are held together via collagenous fibers running from the matrix of one bone to the matrix of the other bone.
NO joint cavity; little to no movement

7. Structural Classifications
Types of Fibrous Joints:
Sutures: Found only in the bones of the skull
Irregular edges provide added strength against fractures.
Synostosis or Bony Joint: When a suture is replaced by bone.
Syndesmosis: More fibrous tissue than a suture, but permits a very small degree of movement
Examples: Distal tibiofibular joint
Gomphoses: A cone-shaped peg fitting into a socket.
ONLY found where teeth attach.

8. Sutures
Syndesmosis
Gomphoses

9. Structural Classification
Cartilaginous Joints: Bones are held together by hyaline or fibro cartilage.
DO NOT contain a joint cavity.
Allow little to no movement.

10. Structural Classification
Types of Cartilaginous Joints:
Synchondroses: Made of hyaline cartilage.
Found in epiphyseal plates connecting the epiphysis and diaphysis of growing bone
Found where the rib attaches to the sternum
Symphyses: A flat disk of fibrocartilage connects the bones
Found in the public symphysis or the intervertebral joints
Slightly moveable

11. Synchondroses
Symphyses

12. Functional Classification
Diarthroses: Freely moveable synovial joints
Ex. Shoulder, hip, finger, knee
Amphiarthrosis: Slightly moveable joints
Ex. Symphysis pubis and intervertebral discs
Synarthroses: Immovable joints
Ex. Sutures, epiphyseal plates of long bones

13. Diarthroses
Synarthroses
Amphiarthrosis

14. Synovial Joints
Bones covered by articular cartilage, which reduces friction between bones & absorbs shock
Articular Capsule: Surrounds each synovial joints, composed of…
Fibrous Capsule: An outer layer
Synovial Membrane: Inner layer; secretes synovial fluid
Synovial Fluid: Reduces friction, supplies nutrients, contains phagocytes to help remove debris from the joint
Meniscus: Cushy pad contained by some joints to further absorb shock

15. Synovial Joints
Ligaments: Tough connective tissue bands arranged in capsule bundles.
Run from bone to bone across the joint.
Helps stabilize and strengthen the joint
Bursae: Fluid-filled sacs beneath the muscles
Help tendons glide easily over joints
Bursitis: Inflammation of the bursae from overexertion of a joint
Tendon Sheaths: Thin membrane enclosing the tendon.
Help reduce friction at joints.

17. Types of Synovial Joints
Ball-And-Socket Joints:
Highly moveable
Multiaxial
Examples: Shoulder & hip joints

18. Types of Synovial Joints
Planar Joints: “Gliding Joints”
Permit some side-to-side & back-and-forth movement
Nonaxial
Examples: Joints between carpal & tarsal bones & between the scapula and clavicle

19. Types of Synovial Joints
Pivot Joints: Where a projection on one bone fits into a ring shaped ligament on the other bone.
Uniaxial (allows for rotationa round one axis only)
Examples: Atlanto-axial joint (allows side-to-side head shakes) & where the radius articulates to the ulna.

20. Types of Synovial Joints
Hinge Joints: Act like a hinge on a door
Allow for uniaxial or monoaxial swinging motion
Examples: Knee, elbow, ankle, finger, toe joints

21. Types of Synovial Joints
Condyloid Joints: Occur where an oval convex surface fits into a similar shaped concave depress on the next bone.
Biaxial
Examples: Metacarpophalangeal joints of the wrist.

22. Types of Synovial Joints
Saddle Joint: Named for its shape
Biaxial
Only ONE: Where the thumb metacarpal articulates with the trapezium of the wrist
Allows for the opposable thumb

24. Joint Movement
Flexion: Movement that decreases the angle of the bone in a joint
Example: Bending your arm at the elbow toward you
Flexing the knee to limb stairs

25. Joint Movement
Extension: Movement that increases the angle of a joint or straightens the joint, returning it to its anatomical position.
Example: Straightening your arm back out.

26. Joint Movement Hyperextension: Extension of a joint beyond 180 degrees
Example: Tilting your head back to look up at the ceiling

27. Joint Movement
Abduction: Movement of a body part away from the midline
Example: Raising the humerus (upper extremity) laterally at the shoulder

28. Joint Movement Adduction: Movement of a body part toward the midline
Example: Pulling your thighs together or moving the humerus back to the anatomical position

29. Joint Movement
Circumduction: Movement in which one end (usually the proximal end) of an appendage stays relatively stationary while the other end (usually distal) makes a circular motion
Example: Making a windmill motion with the arm

30. Joint Movement
Rotation: Movement in which a bone revolves around its longitudinal axis
Example: Twisting at the waist or turning your head from side to side

31. Joint Movement Depression: Movement that lowers a bone vertically
Example: Opening the mouth
Elevation: Movement that raises a bone vertically
Example: Closing the mouth

32. Joint Movement Protraction: Movement of a bone anteriorly
Example: Jutting your chin out
Retraction: Movement of a bone posteriorly
Example: Pulling your chin back in after jutting it out

33. Joint Movement Supination: Rotating the arm palm upward.
Pronation: Rotating the hand palm downward

34. Joint Movement
Inversion: When the soles of the feet turn medially to face each other.
Eversion: Turns the soles of the feet laterally to face away from each other.

35. Joint Movement Dorsiflexion: The act of pointing the toes upward.
Plantar Flexation: Pointing the toes downward.

36. Joint Movement
Opposition: When the thumb reaches across the palm to touch the fingers
Useful for grasping & manipulating objects

37. Joint Movement
A great webside that goes through all the types of joint movement for each major joint…