The Shoulder

Question 1

What makes up the shoulder?

Answer 1

The pectoral, scapula and lateral supraclavicular regions

Question 2

What makes up the pectoral girdle?

Answer 2

Sternum, clavicle and scapula

Question 3

What is the role of the pectoral girdle?

Answer 3

Very mobile, bony ring to keep arm away from body so it has a great range of movement

Question 4

What is the pectoral girdle like posteriorly?

Answer 4

It is incomplete as the scapula doesn’t articulate with the vertebral column via bone but does so by muscle

Question 5

What is the pectoral girdle like anteriorly?

Answer 5

The clavicle articulates with the axial skeleton

Question 6

Where do the axial and appendicular skeleton articulate?

Answer 6

At the sternoclavicular joint between the manubrium of the sternum and the clavicle

Question 7

What is the shape of the clavicle and why?

Answer 7

S shaped as it gives it compressibility and resilience

Question 8

Where is the clavicle? (where does it end)

Answer 8

Anterior bone, overlies 1st rib and ends at the acromioclavicular joint

Question 9

Where/what is the acromion?

Answer 9

Lateral bone of the scapula at the end of the spine, runs posteriorly for muscles to attach to, top of glenohumeral joint

Question 10

What are some features of the scapula?

Answer 10

Posterior, triangle shaped, glenoid cavity with glenohumeral joint, muscle attachment bone, overlies the rib cage posteriorly

Question 11

What is a clavicle fracture caused by?

Answer 11

Direct or indirect force, force of falling onto the hand travels up the bones in forearm and arm to reach the final clavicle bone.

Question 12

What movements occur in a clavicle fracture?

Answer 12

Weight of the arm drags the lateral fragment of the clavicle inferiorly and the sternocleidomastoid pulls the medial fragment superiorly

Question 13

What positional change can be seen from a clavicle fracture?

Answer 13

Lateral side is lower whilst medial side is higher pushing skin up as bone is very superficial anyway, also arm may be a little bit lower

Question 14

What is the sternocleidomastoid muscle?

Answer 14

Anterior muscle in the neck, at the sternum-clavicle-mastoid process joint.

Question 15

Who most commonly has clavicle fractures? and why

Answer 15

Makes up 2-5% of adult fractures but more so in children as clavicle is the last bone to ossify.

Question 16

What does the clavicle protect? What does this mean?

Answer 16

The apex of the lung, the brachial plexus and the major underlying vessels SO all at risk if clavicle is damaged in a fracture for example fragments of bone can damage lungs causing pneumothorax

Question 17

What ribs does the scapula over lie?

Answer 17

2nd-7th ribs

Question 18

What does the spine of the scapula separate?

Answer 18

The supraspinous fossa and the infraspinous fossa

Question 19

What is at the lateral end of the scapula?

Answer 19

The acromion which forms the subcutaneous point of the shoulder

Question 20

What is the shape of the scapula?

Answer 20

triangular and flat

Question 21

What features are seen on the anterior view of the scapula?

Answer 21

Glenoid cavity, acromion, coracoid process, subscapular fossa

Question 22

What features are seen on the posterior view of the scapula?

Answer 22

Supaspinous fossa, coracoid process, acromion, supraspinous fossa, neck of scapula, infraspinous fossa

Question 23

What is the largest bone in the upper limb?

Answer 23

Humerus

Question 24

Where does the humerus articulate with the scapula?

Answer 24

Glenohumeral joint

Question 25

What is a tuberosity and what bone has it?

Answer 25

Protuberance for muscle tendons to attach to | Humerus - greater tuberosity is larger and anterior, lesser tuberosity,

Question 26

What separates the tuberosities

Answer 26

Bicipital groove/inter-tubicular groove which tendon form coracoid process runs through

Question 27

What are the 3 main joints in the shoulder?

Answer 27

Sternoclavicular Joint Acromioclavicular Joint Glenohumeral Joint

Question 28

What structures meet at the sternoclavicular joint?

Answer 28

Manubrium of the sternum, clavicle, 1st costal cartilage

Question 29

What is the strongest joint and the weakest joint?

Answer 29

Strongest - sternoclavicular | Weakest - Glenohumeral joint

Question 30

What ligaments are in the sternoclavicular joint?

Answer 30

Costoclavicular ligament Anterior sternoclavicular ligament Interclavicular ligament

Question 31

What does the costoclavicular ligament attach?

Answer 31

The sternoclavicular joint to the 1st rib limiting its movement

Question 32

Why does the sternoclavicular joint have limited movement?

Answer 32

Costoclavicular ligament joins sternoclavicular joint to 1st rib

Question 33

What is the role of the interarticular disc?

Answer 33

Holds the manubrium and the clavicle together and closely packs them, made up of fibrous tissue

Question 34

What structures make up the acromioclavicular joint?

Answer 34

Acromion and clavicle

Question 35

Where is the acromioclavicular joint found?

Answer 35

2-3cm from the point of the shoulder

Question 36

What is special about the acromioclavicular joint?

Answer 36

No muscles cross it and instead it is moved by the muscles of the scapula

Question 37

How strong is the acromioclavicular joint?

Answer 37

stronger than glenohumeral joint but weaker than sternoclaviular joint

Question 38

What movement can occur in the acromioclavicular joint? What muscles cause them?

Answer 38

Related to scapula movements: depression (gravity) elevation (trapezium) Protraction (serratous anterior and pectoralis minor) Retraction (trapezium) Upward rotation (trapezium and serratous anterior) Downward rotation (latissimus dorsi)

Question 39

What is special about the latissimus dorsi?

Answer 39

It is the only muscle which moves both the upper and lower limb

Question 40

What structures make up the glenohumeral joint?

Answer 40

Glenoid cavity and the humerus head

Question 41

What is the glenoid labrum? What is its role? How does it work?

Answer 41

Shallow glenoid cavity which is deepened by the fibrocartilage ring. Forms a suction cup to hold the humerus head inside the cavity, thin film of synovial fluid between the humerus and the glenoid cavity creates surface tension

Question 42

What is the weakest joint in the body?

Answer 42

Glenohumeral joint

Question 43

How is there such a large freedom of movement at the glenohumeral joint?

Answer 43

Loose fibrous joint capsule, baggy with lots of space around the humerus head

Question 44

What movements can occur at the glenohumeral joint and by which muscles?

Answer 44

Flexion - deltoid (anterior part), pectoralis major, coracobrachialis stabilises the joint Extension - latissimus dorsi, deltoid (posterior part), teres major, triceps brachi stabilise joint Abduction - deltoid (all of it), supraspinatus for the last 10 degree Adduction - latissimus dorsi, pectoralis major, mainly gravity Medial and lateral rotation - subscapularis, suprasniatus, infraspinatus, teres minor

Question 45

Why Is the supraspinatus at risk of damage?

Answer 45

As goes under the acromion

Question 46

Where are the rotator cuff muscles and what do they do?

Answer 46

Form musculotendinous cuff around the glenohumeral joint which blends with articular capsule Attach to the greater and lesser tuberosity Contract and hold large humerous head in shallow glenoid cavity

Question 47

What happens at the scapulothoracic joint?

Answer 47

Head of the humerus uses articular surface for 90 degree turn and the remainder is from scapula rotation using th serratus anterior and trapezium

Question 48

For every 15 degree shoulder abduction how much does the glenohumeral and scapulothoracic joints contribute?

Answer 48

Glenhomueral - 15 degrees and scapulothoracic 5 degrees

Question 49

In a 180 degree turn how much of the turn occurs where?

Answer 49

glenohumeral - 120 degrees, scapulothoracic - 60 degrees

Question 50

What movements does scratching your back form the top use?

Answer 50

External rotation and abduction

Question 51

What movements does scratching your back form the side/bottom use?

Answer 51

Internal rotation and adduction

Question 52

What is a bursa?

Answer 52

Extension of a joint cavity

Question 53

What is the role of bursa?

Answer 53

Act as cushions to reduce friction

Question 54

What is the risk of bursa?

Answer 54

Bursa can become inflamed and damaged which would damage the tendon underneath

Question 55

What is an example of bursitis?

Answer 55

Subacromial bursa - pain and inflammation on abduction of the arm

Question 56

Which joint is most likely dislocated?

Answer 56

Glenohumeral

Question 57

What are the movements in a glenohumeral dislocation?

Answer 57

joint fully abducted tilting head of humerus inferiorly onto weaker part of joint Stronger flexor and adductor muscles pull humeral head anteriorly Gravity pulls humerus inferiorly so rounded profile of the shoulder is lost

Question 58

What happens to the glenoid labrum in a glenohumeral dislocation?

Answer 58

Stripped from anterior aspect of glenoid cavity making the joint weaker

Question 59

How might an axillary nerve injury occur? What does this result in?

Answer 59

From glenohumeral dislocation as axillary nerve has close relationship with inferior part of glenohumeral joint Innervates the deltoid so abduction is impaired Loss of sensation over regimental badge