MSK - Arm

Question 1

What is the clinical term to describe pins and needs?

Answer 1

Paresthesia

Question 2

What is olecranon bursitis? And what causes it?

Answer 2

Inflammation and swelling behind the elbow

Trauma, prolonged pressure, infection, medical conditions e.g RA or gout

Question 3

What muscles are supplied by the musculocutaneous nerve?

All the muscles of the anterior arm

Answer 3

Biceps brachii
Brachialis
Coracobrachialis

Can be recalled as BBC

Question 4

Where can the scaphoid be palpated?

Answer 4

Anatomical snuff box

Question 5

What makes up the cubital fossa? (Lateral to medial) (4)

Answer 5

Radial Nerve
Biceps Tendon
Brachial Artery
Median Nerve

‘Really Need Beer To Be At My Nicest’

Question 6

What are the key structures for concern for a surgical neck fracture of the humerus?

Answer 6

Axillary artery and posterior circumflex artery

Question 7

What is the effect of damage to the Axillary nerve?

Answer 7

Paralysis to the deltoid and teres minor muscles. The patient will not be able to abduct their arm.
Could have sensory loss of skin over lower deltoid

Question 8

What two structures does the humerus articulate with posteriorly?

Answer 8

Scapula and clavicle

Question 9

Name three important anatomical features of the proximal humerus.

Answer 9

Head
Anatomical neck
Surgical neck

Question 10

Where does the head of the humerus sit?

Answer 10

Glenoid cavity of the scapula

Question 11

What is the deep groove on the humerus called?

What runs through this groove?

Answer 11

Intertubercular sulcus

The tendon of the long head of the Biceps brachii runs through this groove

Question 12

In what position is the greater and lesser tubercle situated?

Answer 12

Greater tubercle - located laterally on humerus

Lesser tubercle - located more medially on the bone

Question 13

What four muscles attach anteriorly to the humerus?

Answer 13

Corocobrachialis
Deltoid
Brachialis
Brachioradialis

Question 14

What lies in the radial groove on the shaft of the humerus?

Answer 14

Radial nerve

Profunda brachii artery

Question 15

What type of humerus fracture could easily damage the radial nerve and Profunda brachii artery?

Answer 15

Mid shaft fracture

Question 16

How would a mid shaft fracture effect wrist extension?

Answer 16

The radial nerve innervates the extensors of the wrist and so when damaged the extensors will be paralysed. This results in unopposed flex ion of the wrist known as wrist drop.

Question 17

What bones does the distal part of the humerus articulate with?

Answer 17

Radius and ulna at the elbow joint

Question 18

In what orientation are the epicondyles (projections of bone) on the humerus.
Which is the largest?

Answer 18

Lateral and medial epicondyles

Medial epicondyle is much larger.

Both can be palpated at the elbow

Question 19

What nerve passes along the posterior side of the medial epicondyle? And where can it be palpated?

Answer 19

Ulnar nerve - can be palpated at medial epicondyle

Question 20

What are the names of the three depressions on the distal portion of the humerus which accommodate the forearm bones during movement at the elbow?

Answer 20

Coronoid fossa
Radial fossa
Olecrannon fossa

Question 21

What are the common fractures of falling on a flexed elbow?

What artery may be damaged?

Answer 21

Supracondylar and medial epicondyle

Brachial artery

Medial epicondyle fracture could damage the ulnar nerve - deformity known as ulnar claw.

Question 22

What does a ‘Popeye sign’ show?

Answer 22

Rupture of the long head of the biceps brachii

The patient would not notice much weakness in the upper limb due to the action of the brachialis and supinator muscles

Question 23

Where does the coracobrachialis lie in relation to the biceps brachii?
Where does it originate from?
What is its function?
What nerve innervates it?

Answer 23

Deep within the muscle

Coracoid process of scapula

Flexor of the arm at the shoulder

Musculocutaneous nerve C5 C6 C7 (mainly C6)

Question 24

How many heads does the triceps brachii have?

What is its location?

What are the heads and where do they originate?

What is the role of the tricep?

What nerve innervates it?

What does a tap on the triceps tendon test?

Answer 24

3

Posterior of the arm

Long head - infraglenoid tubercle
Lateral head - humerus, superior to radial groove
Medial head - humerus, inferior to radial groove

Extension at the elbow

Radial nerve

Spinal nerve C7

Question 25

What are the two heads of the pectoralis major?

What nerve is the pectoralis major innervated by?

What is the function of the pectoralis major?

Answer 25

Clavical are head (attaches to clavicle) and sternocostal head (attaches to sternum) Fibres from both heads attach to edge of inter tubercular groove.

Medial and lateral pectoral nerves dervied from the brachial plexus

Adduct and medially rotate humerus at the shoulder. Clavicular head also performs flexion.

Question 26

What nerve is the pectoralis minor innervated by?

What effect does contraction of the pectoralis minor have?

Answer 26

Medial pectoral nerve

Depresses the shoulder

Question 27

What is the function of the Serratus anterior?

What ribs does it originate from?

What nerve is it innervated by?

What is winging of the scapula?

Answer 27

Rotate the scapula - allowing arm to be raised over 90 degrees.

Ribs 2-8

Long thoracic nerve

Damage to long thoracic nerve, Serratus anterior will become paralysed. Pushing against a wall, scapula is no longer held against rib cage and protrudes out.