Anatomy of the shoulder region

Question 1

Skeletal components

Answer 1

Clavicle

Scapula

Humerus

Joints

• glenohumeral joint
• acromioclavicular joint

Question 2

Pectoral girdle

Answer 2

Clavicle

Scapula

Question 3

Ligaments of the shoulder region

Answer 3

Stabilise/ support the shoulder region

• coracoclavicular
• acromioclavicular
• coracoacromial
• glenohumeral

Question 4

Coracolavicular

Answer 4

Two parts

Major stabilising ligament

Question 5

Coracoacromial

Answer 5

Forms arch

Provides support for head of humerus

Prevents superior dislocation

Question 6

Glenohumeral joint

Answer 6

Highly mobile ball and socket joint

• abduction/ adduction
• flexion/ extension
• lateral/ medial rotation
• circrumduction

Question 7

Abduction of the arm

Answer 7

Performed by deltoid

Supplied by axillary nerve

Question 8

Deltoid

Answer 8

Origin: spine of scapula and acromion and clavicle

Insert: deltoid tuberosity

Question 9

Deltoid muscle fibres

Answer 9

Posterior fibres: extension and lateral rotation

Anterior fibres: flexion and medial rotation

Question 10

Adduction of the arm

Answer 10

Performed by latissimus dorsi, pectoralis major

Question 11

Abduction/ adduction of the arm

Answer 11

Glenohumeral joint accommodates parts of movement

Rotation of scapula increases range of movement

Question 12

Flexion of the arm

Answer 12

Short head of biceps

Long head of biceps

Coracobrachialis

Anterior fibres of deltoid

Question 13

Extension of the arm

Answer 13

Long head of triceps

Posterior fibres of deltoid

Latissimus dorsi

Question 14

Glenohumeral joint stability

Answer 14

Large humeral head

Shallow glenoid fossa

Unstable structure

Most frequently dislocated joint

Question 15

Factors increasing stability

Answer 15

Coracoacromial arch

Glenohumeral ligaments

Deepening of glenoid fossa by glenoid labrum

Long heads of biceps (above) and triceps (below)

Tendons of rotator cuff muscles

Question 16

Coracoacromial arch

Answer 16

Prevents superior dislocation

Question 17

Glenohumeral ligaments

Answer 17

Supports anterior of joint

Question 18

Glenoid labrum

Answer 18

Deepends glenoid fossa

Question 19

Long head of niceps and triceps

Answer 19

Split joint

Long head biceps passes through capsule

Question 20

Tendons of the rotator cuff

Answer 20

Four muscles

Insert on humerus close to joint

Fuse with the joint capsule

Forms cuff around joint

Question 21

Rotator cuff muscles

Answer 21

Supraspinatus

Infraspinatus

Teres minor

Subscpularis

Surround joint on all sides except inferiorly

Question 22

Rotator cuff muscles insertion

Answer 22

Supraspinatus, infraspinatus and teres minor insert into the greater tubercle

Question 23

Rotator cuff function

Answer 23

Together: stabilise humeral head on glenoid fossa

Supraspinatus: initiate abduction

Infraspinatus: lateral rotation

Teres minor: lateral rotation

Subscapularis: medial rotation

Question 24

Teres major

Answer 24

Should also be considered with the rotator cuff muscles

Performs medial rotation

Stabilises the humerus during abduction

Question 25

Supraspinatus impingement

Answer 25

Supraspinatus most commonly injured Limited space for tendon under coracoacromial arch

Question 26

Blood supply

Answer 26

Rich blood supply Scapula anastomosis Allows continuous supply of blood to shoulder region during movement From subclavian and axillary arteries

Question 27

Nerve supply to the shoulder

Answer 27

From the brachial plexus Posterior cord Suprascapular nerve

Question 28

Cords of the brachial plexus

Answer 28

Within axilla Below pectoralis minor

Question 29

Posterior cord

Answer 29

Upper/ lower subscapular nerves- subscapularis, teres major Thoracodorsal nerve- latissimus dorsi

Question 30

Quadrangular space

Answer 30

Between teres minor, humerus, teres major, long head of triceps Clinical- fractiure of surgical neck can damage nerve and vessel

Question 31

Lateral cord

Answer 31

Lateral pectoral nerve- pectoralis major

Question 32

Medial cord

Answer 32

Medial pectoral nerve- pectoralis major/ minor Medial cutaneous nerves to arm and forearm