Shoulder and Arm

Question 1

What is the progression of the major artery as it passes from the torso to the arm and down to the forearm?

Answer 1

(Brachiocephalic trunk)
Subclavian
Axillary
Brachial 
Ulnar and Radial (Paired branch)

Question 2

What spinal nerve roots make up the brachial plexus?

Answer 2

C5-T1

Question 3

What does the shoulder girdle consist of?

Answer 3

Scapula
Clavicle
Associated musculature

Question 4

What are the dorsal muscles?

Answer 4

Trapezius
Rhomboids
Latissimus dorsi

Question 5

What is the function of the serrates anterior?

Answer 5

It is a ventrolateral muscle which attaches to the medial border of the scapula and protracts and stabilises the pectoral girdle

Question 6

What muscles are involved in moving the scapula?

Answer 6

Trapezius
Levator scapulae
Rhomboids
Pectoralis minor
Serrates anterior

Question 7

What can result from weakness of the serrator anterior?

Answer 7

Winging of the scapula

Question 8

What makes up the ventral musculature of the shoulder girdle?

Answer 8

Pectoralis major

Serratus anterior

Question 9

What action does contraction of the ventral muscles of the shoulder girdle cause?

Answer 9

Adduction

Question 10

What is glenohumeral rhythm?

Answer 10

A combination of abduction of the humerus and the upward rotation of the scapula
It allows the abduction of the arm to move further than 120° without being interrupted

Question 11

What is the function of the deltoid?

Answer 11

Involved in almost all movements of the glenohumeral joint but chiefly abduction

Question 12

What makes up the posterior group of the short scapular muscles?

Answer 12

Supraspinatus
Infraspinatus
Teres minor
Teres major (not stabilising - causes movement)

Question 13

What makes up the anterior group of the short scapular muscles?

Answer 13

Subscapularis

Question 14

What movements of the glenohumeral joint are caused by the posterior group of short scapular muscles?

Answer 14

Abduction

Lateral rotation

Question 15

What movements are caused by the anterior group of short scapular muscles?

Answer 15

Medial rotation

Question 16

What muscles attach to the greater tuberosity of the humerus?

Answer 16

Supraspinatus
Infraspinatus
Teres minor

Question 17

What muscles attach to the lesser tuberosity of the humerus?

Answer 17

Subscapularis

Question 18

How much is the head of the humerus retroverted by?

Answer 18

~30°

Question 19

What are the functions of the clavicle?

Answer 19

Acts as a strut to support the shoulder and keep the shoulder girdle out to length for function
Protects the brachial plexus and vessels

Acts as an attachment for the muscles:

• Trapezius
• Deltoid
• Pectoralis major
• Subclavius
• Sternocleidomastoid
• Sternohyoid

Question 20

What muscles attach to the clavicle?

Answer 20

• Trapezius
• Deltoid
• Pectoralis major
• Subclavius
• Sternocleidomastoid
• Sternohyoid

Question 21

What clavicular ligaments exist?

Answer 21

Acromio-clavicular ligament
Coraco-acromial ligament
Coraco-clavicular ligament

Question 22

What attaches to the coracoid process of the scapula?

Answer 22

3 Ligaments:

• Coracoacromial
• Coracoclavicular (coronoid and trapezoid)

3 Muscle origins:

• Coracobrachialis
• Short head of biceps

2 Sides:

• Lateral side
• Medial side - ‘where the clockwork lies’

Question 23

How is the acromioclavicular joint disrupted?

Answer 23

Fall onto the point of shoulder

Question 24

What type of joint is the glenohumeral joint?

Answer 24

Synovial ball and socket joint

Question 25

What have to be balanced in a joint?

Answer 25

Mobility vs. Stability

Question 26

Discuss whether the shoulder is more mobile or stable

Answer 26

Most mobile joint in the body
Most commonly dislocated are joint in the body
Static stabilisers - labrum, capsule, ligaments
Dynamic stabilisers - muscles - intrinsic (rotator cuff) and extrinsic (large)

Question 27

What are the characteristics of the capsule of the glenohumeral joint?

Answer 27

Thin and loose
2 openings - one for the tends of the long head of the biceps, one for the sub scapular bursa
The inferior part of the capsule is the only part not reinforced by the rotator cuff muscles - the weakest area. Long, loose redundant fold hanging down into the axilla when arm is down by side.
Thin anteriorly - swelling can be seen if large effusion present

Question 28

How does adhesive capsulitis appear on an MRI?

Answer 28

Capsule is thickened and fibrous with a reduced inferior recess

Question 29

What is characteristic of a shoulder effusion?

Answer 29

Fusion with atrophy of the musculature (rotator cuff arthropathy)
Swelling esp. anteriorly

Question 30

What is the labrum?

Answer 30

A fibrocartilagenous lip
Elevates the glenoid lip
Doubles the glenoid depth and increases the surface area
Acts as a channel block limiting glenohumeral translation

Question 31

Where does the subacromial bursa sit?

Answer 31

On the top/front/side of the shoulder (similar to a Franchman’s beret)

Question 32

What is the function of the subacromial bursa?

Answer 32

Allows free movement of supraspinatus tendon between the humeral head and acromion, of the humeral head under acromion and of deltoid over the humeral head

Question 33

Where is the subacromial bursa found?

Answer 33

Starts superiorly in tunnel formed by acromion, coracoacromial ligament and humeral head

Question 34

What do the rotator cuff muscles do?

Answer 34

Blend with glenohumeral joint capsule to protect and give stability
Hold head of humerus against glenoid cavity during shoulder movements allowing the big muscles to act
Infraspinatus, subscapularis and teres minor are rotators of the shoulder

Question 35

What joints combine to produce shoulder function?

Answer 35

Sternoclavicular joint
Acromioclavicular joint
Glenohumeral joint
Scapulothoracic articulation