The Shoulder

Question 1

Name the bones of the pectoral girdle

Answer 1

clavicles, scapula, acromion (of scapula) and manubrium of the sternum

Question 2

What is the role of the clavicles in the pectoral girdle?

Answer 2

Connects the upper limb to the trunk via the sternoclavicular joint, and this is the only connection of the upper limb to the rest of the body

Question 3

What is the purpose of the pectoral girdle?

Answer 3

To keep the arm away from the thorax to allow maximum freedom of movement.

Question 4

Describe what would happen if the clavicle was fractured

Answer 4

Weight of arm drags the lateral fragment inferiorly and the action of SCM muscles pulls the medial fragment superiorly leading to fraction. As clavicle also protects the brachial plexus, it’s important to ensure there’s no neurovascular damage incurred.

Question 5

Name the visible structures present on the scapula

Answer 5

ANTERIOR: subscapular fossa, acromion, coracoid process and glenoid cavity
POSTERIOR: supraspinous fossa, infraspinous fossa, neck of scapula

Question 6

Describe the location of the scapula

Answer 6

It’s a triangular flat bone on the posterolateral aspect of the thorax and overlies the 2nd to 7th ribs

Question 7

Describe the function of the scapula

Answer 7

Point of attachment for many shoulder/pectoral girdle muscles

Question 8

What is the subcutaneous point of the shoulder indicated by?

Answer 8

The acromion, which is the lateral end of the scapula spine.

Question 9

Describe the sternoclavicular joint

Answer 9

This is a very strong joint, connects clavicle and manubrium (and first costal cartilage). Strength is due to strong ligaments.

Question 10

Describe the acromioclavicular joint

Answer 10

Joint between acromion and clavicle and there are no muscles crossing this joint; muscles moving the scapula move the AC joint, it also has an articular disc as well as ligaments to restrict movement

Question 11

What movements are possible at the scapula?

Answer 11

elevation, depression, protraction and retraction, upward and downward rotation

Question 12

Which muscles control scapula elevation?

Answer 12

descending trapezius

Question 13

Which muscles control scapula depression?

Answer 13

none, gravity

Question 14

Which muscles control scapula protraction?

Answer 14

serratus anterior and pectoralis minor

Question 15

Which muscles control scapula retraction?

Answer 15

middle trapezius

Question 16

Which muscles control scapula upward rotation?

Answer 16

descending trapezius and serratus anterior

Question 17

Which muscles control scapula downward rotation?

Answer 17

latissimus dorsi

Question 18

Describe the glenohumeral joint

Answer 18

also known as the shoulder joint; connects glenoid cavity and the head of the humerus

Question 19

Describe how the glenoid cavity is deepened

Answer 19

it is deepened by a ring of fibrocartilage known as the glenoid labrum

Question 20

Which movements are possible at the glenohumeral joint?

Answer 20

All of them

Question 21

Name the chief flexors of the shoulder joint

Answer 21

pectoralis major and deltoid

Question 22

Name the chief extensors of the shoulder joint

Answer 22

latissimus dorsi and deltoid

Question 23

Name the chief abductors of the shoulder joint

Answer 23

first ten degres is supraspinatus, thereafter is deltoid

Question 24

What is extension at the shoulder joint?

Answer 24

Moving the arm backwards, behind the bum

Question 25

What is flexion at the shoulder joint?

Answer 25

Bringing the arm forwards and upwards

Question 26

Name the chief adductors of the shoulder joint

Answer 26

pectoralis major and latissimus dorsi

Question 27

Name the chief medial rotator of the shoulder joint

Answer 27

Subscapularis

Question 28

Name the chief lateral rotator of the shoulder joint

Answer 28

Infraspinatus

Question 29

What is the ‘physiological scapulothoracic joint’?

Answer 29

The head of the humerus uses all of the available articular surface of the glenoid cavity at 90 degrees, so the scapula rotates to allow the remainder of movement using the serratus anterior and trapezius muscles to facilitate this movement . In abduction, 120 degrees occurs at the glenohumeral joint and 60degrees at the scapulothoracic joint

Question 30

Name the 4 rotator cuff muscles

Answer 30

Supraspinatus, infraspinatus, subscapularis, teres minor

Question 31

Describe how shoulder dislocation may occur

Answer 31

Tend to occur when shoulder joint fully abducted which tilts the head of the humerus inferiorly onto a weaker part of the joint