Lecture 8 - Shoulder Complex and Joint

Question 1

Identify the articulating bones, structural type, and functional type of the sternoclavicular joint.

Answer 1

Articulating bones:

• articular notch of sternum
• clavicle
• first costal cartilage

Structural type:

• synovial
• saddle
• articular disc

Functional type:

• diarthrotic
• triaxial

Question 2

What ligaments are associated with the sternoclavicular joint (list their function if applicable)?

Answer 2

Anterior/posterior sternoclavicular ligament:
-checks anterior and posterior movement

Costoclavicular ligament:

• axis for elevation/depression
• axis for protraction/retraction
• check for elevation

Intraclavicular

Question 3

Identify the articulating bones, structural type, and functional type of the acromioclavicular joint.

Answer 3

Articulating bones:

• concave facet of acromion process
• convex facet of clavicle

Structural type:

• synovial
• plane

Functional type:

• triaxial
• diarthrotic

Question 4

What ligaments are associated with the acromioclavicular joint (list their function if applicable)?

Answer 4

Acromioclavicular ligaments superior/inferior

• reinforce joint capsule
• weak

Coracoclavicular:
-trapezoid (lateral)
-conoid (medial)
—stronger than the clavicle
—axis of elevation/depression
—axis of protraction/retraction
—checks elevation

Question 5

Identify the articulating bones, structural type, and functional type of the glenohumeral joint.

Answer 5

Articulating bones:

• glenoid fossa of scapula
• head of humerus

Structural type:

• synovial
• ball and socket

Functional:

• triaxial
• diarthrotic

Question 6

What ligaments are associated with the glenohumeral joint?

Answer 6

Glenohumeral

• superior
• middle
• inferior

Coracohumeral

Coracoacromial

Question 7

What is the glenoid labrum?

Answer 7

A fibrocartilage meniscus that deepens the articulating surface of the glenoid fossa.

Question 8

What is force coupling?

Answer 8

-two parallel forces in opposite directions acting in a part of a body

Question 9

What is scapulohumeral rhythm?

Answer 9

-simultaneous, coordinated movements of sternoclavicular and acromioclavicular joints during movement of the scapula

Question 10

What is the full ROM of arm abduction?

What joints contribute to this and how much?

Answer 10

FROM: 180 degrees
-glenohumeral joint: 120 degrees
-scapulothoracic movement: 60 degrees
—sternoclavicular joint: 40 degrees
—acromioclavicular joint: 20 degrees

2:1 ratio between glenohumeral movement and scapulothoracic movement

Question 11

What muscles are responsible for elevation of the scapula?

Answer 11

• levator scapulae

- rhomboids

Question 12

What muscles are responsible for depression of the scapula?

Answer 12

-latissimus dorsi

Question 13

What are the muscles of the rotator cuff?

Answer 13

• subscapularis
• supraspinatus
• infraspinatus
• teres minor

(S.I.T.S.)