1. Chapter 9 Lecture Outline See PowerPoint Image Slides
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2. Joints Joints and their classification Synovial joints bony joints
fibrous joints
cartilaginous joints
Synovial joints

3. Joints and Their Classification
Arthrology = study of the joints
Kinesiology = study of musculoskeletal movement
Classified by freedom of movement
diarthrosis (freely movable)
amphiarthrosis (slightly movable)
synarthrosis (little or no movement)
Classified how adjacent bones are joined
fibrous, cartilaginous, bony or synovial

4. Bony Joint (Synostosis)
Gap between two bones ossifies
frontal and mandibular bones in infants
cranial sutures in elderly
attachment of first rib and sternum
Can occur in either fibrous or cartilaginous joint

5. Fibrous Joints (Synarthrosis)
Collagen fibers span the space between bones
sutures, gomphoses and syndesmoses

6. Fibrous Joint -- Sutures
Immovable fibrous joints
bind skull bones together
Lap - overlapping beveled edges
Plane - straight, nonoverlapping edges
palatine processes of the maxillae

7. Types of Sutures

8. Fibrous Joint -- Gomphoses
Attachment of a tooth to its socket
Held in place by fibrous periodontal ligament
collagen fibers attach tooth to jawbone
Some movement while chewing

9. Fibrous Joint -- Syndesmosis
Two bones bound by ligament only
interosseus membrane
Most movable of fibrous joints
Interosseus membranes unite radius to ulna and tibia to fibula

10. Cartilaginous Joint -- Synchondrosis
Bones are joined by hyaline cartilage
rib attachment to sternum
epiphyseal plate in children binds epiphysis and diaphysis

11. Cartilaginous Joint -- Symphysis
2 bones joined by fibrocartilage
pubic symphysis and intervertebral discs
Only slight amount of movement is possible

12. Synovial Joint
Joint in which two bones are separated by a space called a joint cavity
Most are freely movable

13. General Anatomy Articular capsule encloses joint cavity
continuous with periosteum
lined by synovial membrane
Synovial fluid = slippery fluid; feeds cartilages
Articular cartilage = hyaline cartilage covering the joint surfaces
Articular discs and menisci
jaw, wrist, sternoclavicular and knee joints
absorbs shock, guides bone movements and distributes forces
Tendon attaches muscle to bone
Ligament attaches bone to bone

14. Tendon Sheaths and Bursae
Bursa = saclike extension of joint capsule
between nearby structures so slide more easily past each other
Tendon sheaths = cylinders of connective tissue lined with synovial membrane and wrapped around a tendon

15. Components of a Lever
A lever is a rigid object that rotates around a fixed point called a fulcrum
Rotation occurs when effort overcomes resistance
resistance arm and effort arm are described relative to fulcrum

16. Mechanical Advantage of a Lever
Two kinds of levers
lever that helps increase output of force
human moving a heavy object with help of crowbar
lever move object further and faster
movement of row boat with paddle
Types of levers produce either increase in speed or force

17. First-Class Lever
Has fulcrum in the middle between effort and resistance
Atlantooccipital joint lies between the muscles on the back of the neck and the weight of the face
loss of muscle tone occurs when you nod off in class

18. Second-Class Lever Resistance between fulcrum and effort
Resistance from the muscle tone of the temporalis muscle lies between the jaw joint and the pull of the diagastric muscle on the chin as it opens the mouth quickly

19. Third-Class Lever Effort between the resistance and the fulcrum
most joints of the body
The effort applied by the biceps muscle is applied to the forearm between the elbow joint and the weight of the hand and the forearm

20. Range of Motion Degrees through which a joint can move Determined by
structure of the articular surfaces
strength and tautness of ligaments, tendons and capsule
stretching of ligaments increases range of motion
double-jointed people have long or slack ligaments
action of the muscles and tendons
nervous system monitors joint position and muscle tone

21. Axes of Rotation
Shoulder joint has 3 degrees of freedom = multiaxial joint
Other joints – monoaxial or biaxial

22. Types of Synovial Joints

23. Ball-and-Socket Joints
Smooth hemispherical head fits within a cuplike depression
head of humerus into glenoid cavity of scapula
head of femur into acetabulum of hip bone
Multiaxial joint

24. Condyloid (ellipsoid) Joints
Oval convex surface on one bone fits into a similarly shaped depression on the next
radiocarpal joint of the wrist
metacarpophalangeal joints at the bases of the fingers
Biaxial joints

25. Saddle Joints
Each articular surface is shaped like a saddle, concave in one direction and convex in the other
trapeziometacarpal joint at the base of the thumb
Biaxial joint
more movable than a condyloid or hinge joint forming the primate opposable thumb

26. Gliding Joints
Flat articular surfaces in which bones slide over each other
Limited monoaxial joint
Considered amphiarthroses

27. Hinge Joints
One bone with convex surface that fits into a concave depression on other bone
ulna and humerus at elbow joint
femur and tibia at knee joint
finger and toe joints
Monoaxial joint

28. Pivot Joints
One bone has a projection that fits into a ringlike ligament of another
First bone rotates on its longitudinal axis relative to the other
atlantoaxial joint (dens and atlas)
proximal radioulnar joint allows the radius during pronation and supination

29. Flexion, Extension and Hyperextension
Flexion decreases the angle of a joint
Extension straightens and returns to the anatomical position
Hyperextension = extension beyond 180 degrees

30. Flexion, Extension and Hyperextension

31. Abduction and Adduction
Abduction is movement of a part away from the midline
hyperabduction – raise arm over back or front of head
Adduction is movement towards the midline
hyperadduction – crossing fingers

32. Elevation and Depression
Elevation is a movement that raises a bone vertically
mandibles are elevated during biting and clavicles during a shrug
Depression is lowering the mandible or the shoulders

33. Protraction and Retraction
Protraction = movement anteriorly on horizontal plane
thrusting the jaw forward, shoulders or pelvis forward
Retraction is movement posteriorly

34. Circumduction
Movement in which one end of an appendage remains stationary while the other end makes a circular motion
Sequence of flexion, abduction, extension and adduction movements
baseball player winding up for a pitch

35. Rotation Movement on longitudinal axis
rotation of trunk, thigh, head or arm
Medial rotation turns the bone inwards
Lateral rotation turns the bone outwards

36. Supination and Pronation
In the forearm and foot
Supination
rotation of forearm so that the palm faces forward
inversion and abduction of foot (raising the medial edge of the foot)
Pronation
rotation of forearm so the palm faces to the rear
eversion and abduction of foot (raising the lateral edge of the foot)

37. Movements of Head and Trunk
Flexion, hyperextension and lateral flexion of vertebral column

38. Rotation of Trunk and Head
Right rotation of trunk; rotation of head

39. Movements of Mandible Lateral excursion = sideways movement
Medial excursion = movement back to the midline
side-to-side grinding during chewing
Protraction – retraction of mandible

40. Movement of Hand and Digits
Radial and ulnar flexion
Abduction of fingers and thumb
Opposition is movement of the thumb to approach or touch the fingertips
Reposition is movement back to the anatomical position

41. Movements of the Foot
Dorsiflexion is raising of the toes as when you swing the foot forward to take a step (heel strike)
Plantarflexion is extension of the foot so that the toes point downward as in standing on tiptoe
Inversion is a movement in which the soles are turned medially
Eversion is a turning of the soles to face laterally

42. The Humeroscapular Joint
Most freely movable joint in the body
shallowness and looseness
deepened by glenoid labrum
Supported by ligaments and tendons
3 glenohumeral, coracohumeral, transverse humeral and biceps tendon are important joint stabilizer
Supported by rotator cuff musculature
tendons fuse to joint capsule and strengthens it
supraspinatus, infraspinatus, teres minor and subscapularis,
4 Bursae associated with shoulder joint

43. Stabilizers of the Shoulder Joint

44. Tendons of Rotator Cuff Muscles

45. The Elbow Joint
Single joint capsule enclosing the humeroulnar and humeroradial joints
Humeroulnar joint is supported by collateral ligaments.
Radioulnar joint is head of radius held in place by the anular ligament encircling the head

46. Elbow Joint

47. The Coaxal (hip) Joint Head of femur articulates with acetabulum
Socket deepened by acetabular labrum
Blood supply to head of femur found in ligament of the head of the femur Joint capsule strengthened by ligaments

48. Hip Joint Joint capsule strengthened by ligaments pubofemoral
ischiofemoral
iliofemoral

49. Dissection of Hip Joint

50. The Knee Joint Most complex diarthrosis
patellofemoral = gliding joint
tibiofemoral = gliding with slight rotation and gliding possible in flexed position
Joint capsule anteriorly consists of patella and extensions of quadriceps femoris tendon
Capsule strengthened by extracapsular and intracapsular ligaments

51. Knee Joint – Sagittal Section

52. Knee Joint – Anterior and Posterior Views
Anterior and lateral cruciate ligaments limit anterior and posterior sliding movements
Medial and lateral collateral ligaments prevent rotation of extended knee

53. Knee Joint – Superior View
Medial and lateral meniscus absorb shock and shape joint

54. Dissection of Knee Joint

55. Arthritis Arthritis is a broad term for pain and inflammation
Osteoarthritis results from years of joint wear
articular cartilage softens and degenerates
accompanied by crackling sounds called crepitus
bone spurs develop on exposed bone tissue causing pain

56. Arthritis and Artificial Joints
Rheumatoid arthritis is autoimmune attack on joint
antibodies attack synovial membrane, enzymes in synovial fluid degrade the cartilage, bones ossify
remissions occur, steroids and aspirin control inflammation
Arthroplasty is replacement of diseased joint with artificial device called prosthesis

57. Rheumatoid Arthritis

58. Joint Prostheses