Pectoral Girdle and Shoulder

Question 1

What is the name of the joint between the clavicle and the scapula?

Answer 1

Acromioclavicular joint - clavicle articulates with acromium of scapula via its acromial facet

Question 2

How do clavicular fractures usually occur?

Answer 2

Blunt force e.g. sports injury, fall

Question 3

At which point along the clavicle are fractures most common?

Answer 3

Midshaft - middle 1/3 of the bone, as this is thinner and weaker

Question 4

What would the appearance of the shoulder be in a patient with a clavicular fracture?

Answer 4

Shoulder would droop, as the trapezius is trying to support the entire upper limb

Question 5

Where does the scapula articulate with the humerus?

Answer 5

At the glenoid fossa, to form the glenohumeral joint

Question 6

What is the clinical importance of the surgical neck of the humerus?

Answer 6

Most frequently fractured site

Question 7

Which nerve is at risk when the humeral shaft is fractured?

Answer 7

Axillary nerve

Question 8

What are the 6 possible movements of the pectoral girdle?

Answer 8

Protraction
Retraction
Elevation
Depression
Medial rotation 
Lateral rotation

Question 9

What are the attachments of trapezius?

Answer 9

Origin: skull, nuchal ligament, C7 - T12
Insertion: Clavicle, Acromium, Scapula spine

Question 10

Different fibres of trapezius produce different movements of the scapula. What are the movements produced by:

1. Upper fibres
2. Middle fibres
3. Lower fibres
4. All fibres together

Answer 10

1. Upper fibres elevate
2. Middle fibres retract
3. Lower fibres depress
4. All fibres together rotate

Question 11

What is the innervation of trapezius?

Answer 11

Motor - accessory nerve

Proprioception - C3, C4

Question 12

Latissimus dorsi sweeps over the lumbar region and lower thorax and converges to a narrow tendon. Where does this tendon insert of the humerus?

Answer 12

Floor of intertubercular sulcus

Question 13

What is the action of latissimus dorsi?

Answer 13

Elevates scapula

Question 14

What is the innervation of latissimus dorsi?

Answer 14

Thoracodorsal nerve - C6 - C8

Question 15

What is the innervation of the deep dorsal muscles of the pectoral girdle?

Answer 15

Dorsal scapular nerve

Question 16

Which of the deep dorsal muscles of the pectoral girdle elevates the scapula?

Answer 16

Levator scapulae

Question 17

Which of the deep dorsal muscles of the pectoral girdle retract and rotate the scapula?

Answer 17

Rhomboid major and Rhomboid minor

Question 18

Which muscles are responsible for the following movements of the scapula:

1. Protraction (forwards)
2. Retraction (backwards)
3. Elevation
4. Depression

Answer 18

1. Pectoralis major, serratus anterior
2. Rhomboids, middle fibres of trapezius
3. Upper fibres of trapezius, levator scapulae, latissimus dorsi
4. Lower fibres of trapezius

Question 19

Shoulder joint is an articulation between which structures?

Answer 19

Head of humerus and glenoid fossa of scapula. (glenohumeral joint)

Question 20

Which 5 movements are possible at the shoulder joint?

Answer 20

FLAME
Flexion
Lateral rotation
Abduction
Medial rotation
Extension

Question 21

What is the glenoid labrum?

Answer 21

Fibrocartilaginous ridge that deepens the glenoid fossa

Question 22

What causes an anterior dislocation of the shoulder, and what happens?

Answer 22

Caused by excessive extension and lateral rotation

Humeral head is forced anteriorly and inferiorly

Question 23

What structures are at risk during an anterior dislocation of the shoulder joint?

Answer 23

Axillary nerve

Radial nerve

Question 24

Under what circumstances is posterior dislocation of the shoulder likely to be seen?

Answer 24

During seizures / convulsions

Question 25

What group of muscles hold the humeral head securely within the glenoid fossa?

Answer 25

Rotator cuff muscles

Question 26

Name the 4 rotator cuff muscles

Answer 26

``` SITS Subscapularis Infraspinatus Teres minor Supraspinatus ```

Question 27

What action does the deltoid muscle produce?

Answer 27

Powerful abductor of the arm beyond 15 degrees Flexion (anterior fibres) Extension (posterior fibres)

Question 28

What is the innervation of the deltoid muscle?

Answer 28

Axillary nerve

Question 29

What is the action of muscles which attach at the greater tuberosity of the humerus?

Answer 29

Lateral rotation

Question 30

What is the action of muscles which attach at the lesser tuberosity of the humerus?

Answer 30

Medial rotation

Question 31

Which sports are likely to lead to rotator cuff injuries?

Answer 31

Those with overhead actions e.g. tennis

Question 32

What is subacromial bursitis and why does it lead to a 'painful arc'?

Answer 32

Inflammation of bursa which separates supraspinatous tendon from coraco-acromial arch

Question 33

Supraspinatous tendon is often affected by impingement under the coraco-acromial arch, leading to inflammation and tears. How would a patient with this pathology present?

Answer 33

Unable to elevate or roate humerus

Question 34

What is meant by 'frozen shoulder'?

Answer 34

Adhesive capsulitis - shoulder capsule becomes inflamed and stiff

Question 35

What structures form the 4 borders of the quadrilateral space?

Answer 35

Superior - teres minor Inferior - teres major Medial - long head of triceps brachii Lateral - surgical neck of humerus

Question 36

Which artery and nerve are located in the quadrilateral space?

Answer 36

Axillary nerve | Posterior circumflex humeral artery (+vein)

Question 37

What is quadrilateral space syndrome?

Answer 37

Compression of axillary nerve and posterior circumflex humeral artery. Affects athletes who perform overhead movements.