T2 L3: Anatomy of the shoulder region

Question 1

Which bones form the pectoral girdle?

Answer 1

Clavicle and scapula

Question 2

Name some ligaments of the shoulder region

Answer 2

2 Coracoclavicular
Acromioclavicular
Coracoacromial
Superior, middle, and inferior glenohumeral

Question 3

Which ligament in the shoulder prevents superior dislocation?

Answer 3

The coracoacromial ligament

It forms and arch and supports the head of the humerus

Question 4

What is the origin and insertion of the deltoid muscle?

Answer 4

Origin: spine of scapula, acromion process, and clavicle

Insertion: Deltoid tuberosity on the humerus

Question 5

Which nerve supplies the deltoid muscle?

Answer 5

The axillary nerve

Question 6

Which movements does the deltoid muscle allow?

Answer 6

Adduction of the arm
Posterior fibres: extension and lateral rotation
Anterior fibres: flexion and medial rotation

Question 7

Which muscles perform adduction of the arm?

Answer 7

Latissimus dorsi and pectoralis major

Question 8

What happens at the shoulder during overhead abduction?

Answer 8

The glenohumeral joint accommodates for part of the movement but the scapula has to rotate to increase the range of movement

Question 9

Which head of the bicep attaches to the coracoid process?

Answer 9

The short head (more medial)

Question 10

Which muscle flexes the forearm?

Answer 10

The brachialis muscle

Question 11

Which muscles extends the arm?

Answer 11

The triceps, posterior fibres of deltoid, and latissimus dorsi

Question 12

Which muscles extend the forearm?

Answer 12

The lateral and medial head of triceps

Question 13

Which type of shoulder dislocation is the most common?

Answer 13

Anterior dislocation

The humeral head descends inferiorly and ends up anteriorly

Question 14

Which factors increase the stability of the shoulder?

Answer 14

• Coracoacromial arch
• Glenohumeral ligaments
• Deepening of glenoid fossa by glenoid labrum
• Long heads of biceps above the joint and triceps below the joint
• Tendons of rotator cuff muscles

Question 15

What is the function of the glenoid labrum?

Answer 15

It’s a cartilage that deepens the socket of the shoulder

Question 16

What are the 4 rotator cuff muscles?

Answer 16

SITS
Supraspinatus
Infraspinatus
Teres minor
Subscapularis 

They surround joints on all sides except inferiorly

Question 17

Which muscles insert into the greater tubercle of the humerus?

Answer 17

Supraspinatus, Infraspinatus, and teres minor

Question 18

Which movement does the supraspinatus muscle perform?

Answer 18

Initiates abduction

Question 19

Which movement does the infraspinatus muscle perform?

Answer 19

Lateral rotation

Question 20

Which movement does the teres minor muscle perform?

Answer 20

Lateral rotation

Question 21

Which movement does the subscapularis muscle perform?

Answer 21

Medial rotation

Question 22

What is supraspinatus impingement?

Answer 22

When the shoulder catches on nearby bone

There is limited space for the tendon under the coracoacromial arch

Question 23

Which 2 arteries supply the scapular anastomosis?

Answer 23

Subclavian and axillary arteries

Question 24

Where are the cords of the brachial plexus found within the shoulder?

Answer 24

Within the axilla below pectoralis minor

Question 25

Which cord supplies the shoulder?

Answer 25

The posterior cord as it creates the axillary and radial nerves

Question 26

Which 4 structures form the quadrangular space?

Answer 26

Teres minor
Humerus
Teres major
Long head of triceps