MSK - Clinical Arm Shoulder

Question 1

What could be injured with a stab wound to the axilla?

Answer 1

Artery
Vein
Lymph
Nerves - brachial plexus
Lymph nodes
Biceps brachia and coracobreachialis muscle

Question 2

Which is easier to tell on an X-ray anterior or posterior dislocated shoulder?

Answer 2

Anterior

Posterior may need CT

Question 3

Why are some clavicle fractures displaced inferomedially? What is the worry with this?

Answer 3

Inferior due to weight of arm
Medially displaced lateral segment due to action of pectoralis major

Damage to axilla - e.g. upper brachial plexus injury and Erbs palsy

Question 4

What might cause injury to the upper brachial plexus and what symptoms/clinical signs? Which nerve and roots?

Answer 4

Clavicle fracture or squashed baby from birth canal
Erbs palsy

C5 C6 axillary nerve

Question 5

What might cause injury to the lower brachial plexus and what is the symptoms clinical signs? Which nerve(s) and roots?

Answer 5

Falling from a tree

Klumskis palsy - claw like a monkey - due to ulna and sometimes median damage C8-T1

Question 6

How is abduction achieved of the shoulder?

Answer 6

First 15 degrees by supraspinatus

15- 90 by middle fibres of deltoid helped by supraspinatus

Above 90 degrees scapular needs to be rotated by trapezius and serrates anterior

Question 7

What do the supra scapular nerves innervate and why is this relevant in a clavicle fracture?

Answer 7

Supra scapular nerves do the lateral rotator muscles

So damage to these may cause medial rotation - waiters tip

Question 8

What is the arms best supinator?

Answer 8

Biceps brachii

Question 9

What are the three muscles in the arm supplied by the musculocutaneous nerve

Answer 9

BBC

Brachialis
Biceps brachii
Coracobrachialis

Question 10

What is the function of these three muscles BBC

Answer 10

Biceps brachii - supinates, flexion of arm at shoulder and elbow

Brachialis - flexion of arm at elbow

Coracobrachialis - Flexion of arm at shoulder and wear adduction as attaches to coracoid process of the scapula.

Question 11

What muscle in the arm are inverted by the radial nerve?

Answer 11

Triceps brachii

Question 12

What is the functions of triceps brachii?

Answer 12

Extension of the arm at the elbow

Question 13

What are the two muscles in the arm innervated by the axillary nerve?

Answer 13

Teres minor - lateral (external) rotation of the arm at the shoulder

Deltoid - 15-90 degree abduction (middle) Posterior extension
Anterior flexion

Question 14

How many deltoids are there? What do they do?

Answer 14

3
Anterior - flexes the arm at the shoulder
Middle - abduction of the shoulder
Posterior - extends the arm at the shoulder

Question 15

What are the 4 rotator cuff muscles?

Answer 15

SITS

Supraspinatus
Infraspinatus
Teres minor
Subscapularis

Question 16

What are the 6 intrinsic muscles of the shoulder (from scapular and/or clavicle and attach to humerus)

Answer 16

1) Infraspinatus
2) Supraspinatus
3) Subscapularis
4) Teres minor
5) Teres Major
6) Deltoids

Question 17

What are the 4 extrinsic muscles of the shoulder?

Answer 17

1) Trapezius
2) Latissimus dorsi
3) Levator scapulae
4) Rhomboids - major/minor

Question 18

What do the subscapular and suprascapular nerves supply?

Answer 18

Subscapular

• Lower - subscapularis
• Upper subsapularis and theres major

Suprascapular - infraspinatus supraspinatus

Question 19

What is the resting function of the rotator cuff muscles?

Answer 19

Their resting tone helps pull the humeral head into the glenoid fossa

Question 20

What is the glenoid fossa?

Answer 20

Shallow depression in the scapular where the humerus can fit

Question 21

What injuries can occur with the rotator cuffs?

Answer 21

• Tendonitis - most commonly the supraspinatus tendon due to repetitive overhead movements.
• Rotator cuff tears - either acute or degenerative.

Question 22

What are the signs that you might have a rotator cuff tear?

Answer 22

Impingement signs, weak internal rotation, weak external rotation and external rotation lag

Question 23

What artery are you worried about in a humeral neck vs humeral shaft fracture?

Answer 23

Head - posterior circumflex artery (comes off radial)

Shaft - Radial - profunda brachii

Question 24

What are the 5 distinguishing features of a synovial joint?

Answer 24

1) Articular cartilage
2) Synovial membrane
3) Synovial fluid
4) Articular (fibrous) capsule
5) Joint cavity

Question 25

What are the 4 joints of the shoulder/upper limb?

Answer 25

Glenohumeral Sternoclavicular Acromioclavicular Scapulothoracic

Question 26

What type of joint is the sternoclavicular and between what bones?

Answer 26

Synovial | Between the clavicle and the manubrium of the sternum

Question 27

What is calcific supraspinatus tendonitis? What can you get with it? Why could an Xray be normal after a few weeks?

Answer 27

Deposits of calcium hydroxyapatite crystals between the humeral head and the acromium Can get impingement in subacromial space - 10/10 pain - normally resolves and gets absorbed by white cells so good give normal Xray

Question 28

What is the role of the ligaments of the shoulder?

Answer 28

Stabilise the bones

Question 29

What are the 4 major ligaments - which one prevents superior displacement of the humeral head?

Answer 29

Coracohumeral Coracoacromial Transverse humeral ligament (between two tubercles of the humerus) Glenohumeral The corachoachromial ligament is the corachoachromial arch that prevents superior displacement of the humeral head.

Question 30

What is a 'popeye' arm a clinical feature of?

Answer 30

Long head of biceps brachii rupture Long head goes to the supraglenoid tubercle of the scapula

Question 31

Where does the short head of the biceps brachii go

Answer 31

To the coracoid process of the scapula

Question 32

Which two muscles go through the axilla?

Answer 32

Biceps brachi | Coracobrachialis

Question 33

What is the space between the two tubercles on the humerus called and why?

Answer 33

Bicipital groove as the tendon of the long head of the biceps brachii runs here.

Question 34

Where does the levator scapulae originate and insert into? What's its role?

Answer 34

from transverse process of C1-C14 to the medial border of the scapula. Elevates the scapula

Question 35

Which 3 muscles attach to and which tendon runs through the intertubecular groove of the humerus

Answer 35

Biceps brachii long arm runs through the bicipital groove Teres major and Pectoralis major attach to either lip of the bicipital groove and the latissimus doors tendon attaches to the bicipital groove

Question 36

Which muscles insert into the the greater tubercle of the humerus?

Answer 36

Infraspinatus Supraspinatus Teres minor

Question 37

Which muscles inset into the less tubercle of the humerus?

Answer 37

Subscapularis

Question 38

Where do the deltoids originate and insert into?

Answer 38

Originate from the scapula and the clavicle and insert in to the deltoid tuberosity of the humerus

Question 39

Where does the serratus anterior originate and insert into? What is the role (2)?

Answer 39

From ribs 1-8 to the medial aspect of the anterior scapular. They rotate the scapula allowing the arm to be raised over 90 degrees and it also holds the scapula against the ribcage

Question 40

Name 5 muscles that move the scapula

Answer 40

``` Trapezius Latissimus dorsi Levator scapulae Rhomboids Pectoralis minor ```

Question 41

What are the functions of the three different fibre types of the trapezius?

Answer 41

Upper - elevate scapula and rotate during abduction of the arm Middle - Retract scapula (backwards towards midline) Lower - pulls scapula interiorly e.g. if you were carrying heavy bags and your shoulders move down.

Question 42

Where does the trapezius originate from and insert?

Answer 42

Originates from the nuchal ligament, skull and spinous processes of C1-T12 Insert into the clavicle, scapula spine, and acromion

Question 43

What are the functions of the latissimus dorsi?

Answer 43

Extends adducts and medially rotates the arm.

Question 44

Which muscle rotates the gelnoid cavity upwards? And which downwards?

Answer 44

Upwards - upper fibres of the trapezius Downwards - rhomboids

Question 45

What is the origin and insertion of the rhomboids? is major or minor above? What is their function?

Answer 45

Minor is above Originate from C7-T5 Insert into the medial border of the scapula Rotate and retract the scapula