1. Joints and Articulations
Arthrology

3. Joints And Their Classification
A joint, or articulation, is any point at which two bones meet, regardless of whether they are movable at that point
The science of joint structure, function, and dysfunction is called arthrology
The study of musculoskeletal movement is kinesiology

4. Joints And Their Classification
Kinesiology is a branch of biomechanics, which deals with a broad range of motions and mechanical processes in the body, including the physics of blood circulation, respiration, and hearing.

5. About Joints Tendons Ligaments
bind a muscle to bone
Ligaments
bind bone to bone
Both are dense regular connective tissue
About Muscles (acting at a joint)
origin
insertion
action

6. Characterizing Joints
What type of movement does the joint allow?
No movement, limited movement, free movement
What tissue joins the bones?
Fibrous Joints
Fibrous connective tissue (suture, ligament, tooth)
Cartilaginous Joints
Fibrocartilage (pubic symphysis)
Hyaline cartilage (epiphyseal plate, costal cart)
Synovial

7. Types of Movement Synarthrotic Amphiarthrotic Diarthrotic
immoveable, allows no movement
Amphiarthrotic
allows only limited movement
Diarthrotic
freely moveable

8. Types of tissue between bones
Suture (dense CT between bony plates)
Syndesmosis (ligament)
Gomphosis (tooth socket)
Symphysis (fibrocartilage)
Synchondrosis (hyaline cartilage)
Synovial (fluid filled joint)

9. Fibrous Joints
A fibrous joint is two bones joined by fibrous connective tissue.
It is immovable so it is categorized as a synarthrotic joint.
No joint cavity

10. Fibrous Joints
Sutures
Syndesmoses
Gomphoses

11. Suture
In sutures and gomphoses, the fibers are very short and allow for little or no movement

12. Syndesmosis
In syndesmoses, the fibers are longer and the attached bones are more movable: ligament attaches!

13. Gomphosis
Peg in socket

14. Cartilaginous Joints
A cartilaginous joint is two bones joined by cartilage. The cartilage is either fibrocartilage (a symphysis joint) or hyaline cartilage (a synchondrosis).
Fibrocartilage joints (symphyses) are amphiarthrotic (slightly moveable).
Examples are intervertebral discs and the pubic symphysis
Hyaline cartilage joints (synchondroses) are synarthrotic (immovable).
Examples are epiphyseal plates and costal cartilages

15. In a symphysis, two bones are joined by fibrocartilage (A symphysis is amphiarthrotic: slightly moveable)
Symphysis

16. A synchondrosis is a joint in which the bones are bound by hyaline cartilage (A synchondrosis is synarthrotic: not moveable)
Synchondrosis
A synchondrosis is a synarthrosis

17. Synovial Joints
The most familiar type of joint and the most common. It allows a wide range of motion so it is functionally classified as a diarthrotic joint (a diarthrosis)
Examples include the elbow, knee, knuckles, the joints between the wrist and ankle bones
Synovial joints are the most structurally complex type of joint, (having a joint cavity) and are the most likely to develop uncomfortable and crippling dysfunctions

18. Synovial Joints Characteristics
Enclosed chamber, flexible fibrous capsule
A cavity filled with fluid, synovial fluid
An inner membrane that produces lubricating fluid, synovial membrane
Articular cartilages covering ends of bones
Reinforcing ligaments to stabilize
Innervated and vascular

19. Synovial Joint Structure
These surfaces are separated by a narrow space, the joint (articular) cavity, containing a slippery lubricant called synovial fluid. This fluid is rich in albumin and hyaluronic acid, which give it a viscous, slippery texture. It nourishes the articular cartilages, removes their wastes, and makes movements at synovial joints almost friction-free
In synovial joints, the facing surfaces of the two bones are covered with articular cartilage, a layer of hyaline cartilage about 2 mm thick

20. Synovial Joint Structure
In several synovial joints, fibrocartilage grows inward from the joint capsule and forms a pad between the articulating bones
When the pad crosses the entire joint capsule it is called an articular disc

21. Capsule
A connective tissue membrane (articular capsule) encloses the cavity and retains the fluid.
It has an outer fibrous capsule, which acts like a sleeve; it is continuous with the periosteum of the adjoining bones, and an inner, cellular synovial membrane

22. Bursae
A bursa is a fibrous sac filled with synovial fluid, located between adjacent muscles or where a tendon passes over a bone.
Bursae cushion muscles, help tendons slide more easily over the joints, and sometimes enhance the mechanical effect of a muscle by modifying the direction in which its tendon pulls.

23. Bursae and Tendon Sheaths
The knee joint has at least 13 bursae
Figure 9.4a, b

24. Synovial Joint
Bursitis is inflammation of a bursa, usually due to overexertion of a joint.
Tendinitis is a form of bursitis in which a tendon sheath is inflamed

25. Types of Synovial Joints
There are six types of synovial joints, characterized by the motion allowed by the shapes of the bones.
Plane
Hinge
Pivot
Condyloid
Saddle
Ball and socket

26. Plane Joints
The carpal and tarsal bones, between the articular processes of the vertebrae, and at the sternoclavicular joint

27. Hinge Joints
The elbow, knee, and IPJ = interphalangeal (finger and toe) joints

28. Pivot Joints
The atlantoaxial joint between the first two vertebrae and proximal radioulnar joint, where the annular ligament on the ulna encircles the head of the radius

29. Condyloid Joints Metacarpal-phalangeal joints: these are
biaxial condyloid joints

30. Saddle Joints
At the base of the thumb (between the trapezium and metacarpal I) and sternoclavicular joint between the clavicle and sternum.
Saddle joints are biaxial joints; in primate anatomy, allows for the opposable thumb

31. Ball and Socket Joints
Shoulder and hip joints are ball and socket. This type of joint is multiaxial.

32. Three Important Synovial Joints
Knee Joint
Hip Joint
Shoulder Joint

33. The Knee Joint Tibiofemoral joint and patellofemoral joint
The largest and most complex diarthrosis
of the body
Hinge joint, but has movements of gliding, rolling and rotation
3 articulations: lateral and medial articulations of femur and tibia; intermediate articulation of patella and femur. Note: Fibula does not articulate with the femur, only with the tibia.

34. Extracapsular ligaments
Patellar ligament (patellar tendon)
Passes from the apex and margins of the patella distally to the tibial tuberosity
Medial collateral ligament
Extends from the medial epicondyle of the femur to the medial condyle of the tibia
At its midpoint, its fibers are attached to the medial meniscus,
Lateral collateral ligament
Extends inferiorly from lateral epicondyle of femur to lateral surface of the fibular head

35. Two ligaments lie outside the joint capsule:
tibial (medial) collateral ligament.
fibular (lateral) collateral ligament
The two collateral ligaments prevent the knee from rotating when the joint is extended.

36. Cruciate ligaments
There are two ligaments that lie inside the joint capsule. They are deep within the joint cavity, but they are not inside the fluid-filled synovial cavity.
These ligaments cross each other in the form of an X:
the anterior cruciate ligament (ACL)
posterior cruciate ligament (PCL)

37. Intracapsular ligaments
Cruciate ligaments join proximal tibia with distal femur, crisscrossing in the articular capsule
Anterior cruciate ligament (ACL)
Weaker of the two cruciates
Arises from anterior intercondylar area of tibia, attaches at the posteromedial side of the femoral lateral condyle.
Slack when knee is flexed, taut when fully extended
Prevents posterior displacement of femur and hyperextension of knee joint
Posterior cruciate ligament (PCL)
Arises from posterior intercondylar area of tibia, attaches to the anterolateral surface of the medial condyle of femur.
Taut during flexion, prevents anterior displacement of femur on the tibia
Is the main stabilizing factor when weight-bearing during flexed knee position (ie. Walking downhill.)

39. Menisci Medial and Lateral Menisci
Crescent (C-) shaped plates of fibrocartilage located over the medial and lateral tibial condyles
Thicker laterally, thinner inside the joint capsule
Act like shock absorbers
Thicker laterally, taper to thin unattached edges at interior of the joint.

40. In the knee, two fibrocartilages extend inward from the left and right but do not entirely cross the joint
Each is called a meniscus
Menisci absorb the shock of the body weight jostling up and down on the knee and prevent the femur from rocking from side to side on the tibia

41. Anterior View of Flexed Knee
Figure 9.14e, f

42. The ACL and PCL are named according to whether they attach to the anterior or posterior side of the tibia, (not for their attachments to the femur.)
When the knee is extended, the ACL is pulled tight and prevents hyperextension.
The PCL prevents the femur from sliding off the front of the tibia and prevents the tibia from being displaced backward.

43. Knee Joint
Be able to label the drawing with the names of all of the structures of the knee joint, including the bones, ligaments, cartilage, membranes, capsule, menisci, etc.
Know the movements allowed and the movements prevented by the anatomy of the knee.

44. 10 pt Essay Question: Label this (1/2 point each)

45. Essay Answer (a)

46. Essay Answer (b)

47. Quadriceps tendon
Lateral Collateral ligament
Medial Collateral ligament
Lateral Meniscus
Medial Meniscus
Patellar ligament (patellar tendon)

48. Lateral Collateral ligament
Medial Collateral ligament
Lateral Meniscus
Medial Meniscus
Anterior Cruciate ligament
Tibial tuberosity

49. Lateral Collateral ligament
Medial Collateral ligament
Lateral Meniscus
Medial Meniscus
Posterior Cruciate ligament

50. Lateral Collateral ligament
Medial Collateral ligament
Lateral Meniscus
Medial Meniscus
Posterior Cruciate ligament

51. Medial
Meniscus
Lateral
Meniscus
Anterior
Cruciate
ligament
Tibial
tuberosity

52. Hip Joint
Strong, stable ball and socket joint, most moveable of all joints
Transverse acetabular ligament (which bridges the acetabular notch) holds head in beyond its equator.

53. Hip Joint Ligaments Iliofemoral ligament
Y shaped; Attaches to ant infer iliac spine and acetabular rim proximally and inferior intertrochanteric line distally
Prevents hyperextension of the hip during standing
Pubofemoral ligament
Runs from the superior ramus of the pubis and passes laterally and to the intertrochanteric line (passing deep to the iliofemoral ligament.)
Prevents overabduction of the hip joint
Ischiofemoral ligament
Runs from ischial part of acetabular rim, to the neck of femur (best seen from posterior view.)
Prevents hyperextension of the hip by screwing the femoral head deeper into the acetabulum
Ligament of the head of the femur (ligamentum teres)
Weak, little importance in strengthening hip joint
Runs from the transverse acetabular ligament and attaches to the pit
(fovea capitis) of head.

54. Hip Joint
Figure 9.13a, b

55. Posterior View of the Hip Joint
Figure 9.13c, d

56. Hip Ligaments
Be able to label the drawing with the names of the ligaments that attach to the hip.

57. 10 pt Essay Question: Label this

58. Essay Answer: 1 pt each
Anterior
Posterior

59. Diarthrotic, ball and socket joint: Humeral head in glenoid cavity
The Shoulder Joint
Diarthrotic, ball and socket joint:
Humeral head in glenoid cavity

60. Shoulder Joint (Glenohumeral Joint)
Ligaments:
Glenohumeral ligaments : 3 fibrous bands
From the anterior glenoid labrum to the anatomical neck of humerus
Reinforce the anterior part of the articular capsule (and are inside the capsule, not visible from outside.)
Coracohumeral ligament
From base of coracoid process to anterior aspect of greater tubercle of humerus
Transverse humeral ligament
Runs from greater to lesser tubercle of humerus
Creates a channel , bridging over the intertubercular groove
Site for tendon of long head of biceps brachii
Coracoacromial ligament
From inferior aspect of acromion to coracoid process
Forms a protective “arch” preventing superior displacement of the head
Supraspinatus muscle passes under this arch.

61. Shoulder Ligaments

62. Shoulder:Glenohumeral Joint

63. Shoulder Ligaments
Be able to label the drawing with the names of the ligaments that attach the clavicle to the scapula and to the head of the humerus.

64. 10 pt Essay Question: Label this

65. Essay Answer: ½ pt each

66. Ligaments of the Ankle Joint
Figure 9.17c

67. Ligaments of the Ankle Joint
Figure 9.17d