1. Joints of the Human Body

2. Joint is a point of connection between two bones
Strands of connective tissue, ligaments, hold the bones together and ensure the stability of joints

3. Joint Classification
Joints are classified according to their motion capabilities:
Synarthroses
Immovable
Amphiarthroses
Slightly movable
Diarthroses
Allow the greatest amount of motion

4. What is a Ligament
A band of tough fibrous tissue joining two bones together
Ligaments maybe capsular, extrinsic, or intrinsic
Capsular ligaments are thickenings within a fibrous joint capsule
Extrinsic ligaments run between bony joints, around the outside of a synovial cavity
Intrinsic ligaments occur within a synovial cavity and are generally less common than the other types
Ligaments are relatively non-elastic, but flexible enough to allow movement
Their main tasks are to bind bones together, to strengthen and stabilize joints (especially joints, such as the knee and shoulder, where the articulating bones do not fit very tightly together), and to limit joint movement to certain directions

5. Joint Classification Cont’d
Joints are further classified by the material that joints them:
Fibrous joint
Allow no movement
E.g. sutures of the scull
Cartilaginous joints
Allow limited movement
E.g. intervertebral discs
Synovial joints
Allow large range of movements
E.g. hip joint

6. Characteristics of Joints
Ligament
Connects bone to bone
Fibrous non-elastic material that limits motion
Tendon
Connects muscle to bone
Fibrous tissue with some elasticity
Transmits mechanical work from the muscle to move the bone
Disc
Present in interior of some joints to lesson shock
Permits two types of movement to occur simultaneously
Bursa
Collapsed bag with thin walls and a moist inner surface
Eliminates friction when a tendon or muscle comes into contact with another object.

7. Types of Synovial Joints
There are three basic types of synovial joints:
unilateral (rotation only about one axis)
biaxial joints (movement about two perpendicular axes)
multiaxial joints (movement about all three perpendicular axes)

8. Types of Synovial Joints Cont’d
Synovial are further classified into:
1. Hinge Joint
2. Pivot Joint
3. Condyloid Joint
4. Saddle-shaped joint
5. Ball and Socket Joint
6. Plane Joint

9. 1. Hinge (Ginglymus) Joint
Uniaxial
Has one articulating surface that is convex, and another that is concave
E.g. humero-ulnar elbow joint, interphalangeal joint

10. Pivot Joint
Uniaxial
E.g. head of radius rotating against ulna

11. Condyloid (Knuckle) Joint
Biaxial (flexion-extension, abduction-adduction)
The joint surfaces are usually oval
One joint surface is an ovular convex shape, and the other is a reciprocally shaped concave surface
E.g. metacarpophalangeal joint

12. Saddle Joint Biaxial (flexion-extension, abduction-adduction)
The bones set together as in sitting on a horse
E.g. carpometacarpal joint of the thumb

13. Ball and Socket Joint Multiaxial (rotation in all planes)
A rounded bone is fitted into a cup=like receptacle
E.g. shoulder and hip joints

14. Plane (Gliding) Joint Uniaxial (permits gliding movements)
The bone surfaces involved are nearly flat
E.g. intercarpal joints and acromioclavicular joint of the vertebrae

15. Joints of the Pectoral Girdle

16. Sternoclavicular Joint
Connects the sternum to the clavicle
the only joint connecting the pectoral girdle to the axial skeleton
true synovial joint strengthened by an intracapsular disc and extrinsic ligaments

17. Acromioclavicular Joint
unites the lateral end of the clavicle with the acromion process of the scapula
where shoulder separations often occur in sports such as hockey, baseball, and football

18. Glenohumeral Joint Connects the upper limb and the scapula
A typical multiaxial joint
has a wide range of movement at this joint
compromise = relative lack of stability

19. Upper Limb Joints

20. Elbow Joint There are three joints at the elbow: humero-ulnar joint
medial (with respect to anatomical position)
between the trochlea of the humerus and the olecranon process of the ulna
humero-radial joint
lateral
between the capitulum of the humerus and the head of the radius
radio-ulnar joint
between the radius and the ulna

21. Elbow Joint Cont’d Humerus Humero-Ulnar Joint Humero-Radial Joint
Radio-Ulnar Joint
Radius
Ulna

22. Joints of the Pelvic Girdle

23. Hip Joint
- Between the head of the femur and the cup (acetabulum) of the hip bone (os coxae)
Like shoulder joint, hip joint is:
ball and socket joint
multiaxial joint that allows flexion-extension, abduction-adduction and circumduction

24. Illium

25. Hip Joint Cont’d unlike shoulder joint, hip joint is very stable
in fact it is the body’s most stable synovial joint due to:
deepened socked (via lip or fibrocartilaginous labrum )
an intrinsic and very strong extrinsic ligaments
dislocation in sports is not common, but can occur in car collisions
dislocate the head posteriorly or drive it through the posterior lip of the actetabulum

26. Lower Limb Joints

27. Knee Joint Tibiofemoral or knee joint
incredible range of movement (flexion –extension)

28. Knee Joint Cont’d
however, the knee joint is relatively stable due to additional structural supports from:
menisci
shock-absorbing fibrocartilaginous discs
anterior and posterior cruciate ligaments
in the centre of the joint
lateral and medial collateral ligaments
extending from the sides of the femur to the tibia and fibula
the musculature that surrounds it

29. Ankle Joint talocrural or ankle joint involves several bones:
Medial malleolus
Lateral malleolus
Talus
Calcaneus
talocrural or ankle joint
involves several bones:
medial and lateral malleoli of the tibia and fibula
head of the talus
calcaneus (heel bone)