Intrinisic Shoudler Muscles

Question 1

Where do the intrinsic muscles of the shoulder originate from?

Answer 1

The scapula and/or clavicle

Question 2

Where do the intrinsic muscles of the shoulder attach to?

Answer 2

The humerus

Question 3

What are the intrinsic muscles of the shoulder?

Answer 3

Deltoid
 Teres major
 Supraspinatus
 Infraspinatus
 Subscapularis
 Teres minor

Question 4

What muscles are considered to be part of the rotator cuff group?

Answer 4

Supraspinatus
Infraspinatus
Subscapularis
Teres minor

Question 5

What shape is the deltoid muscle?

Answer 5

Triangle

Question 6

What can the deltoid muscle be divided into?

Answer 6

Anterior (clavicular), middle (acromial) and posterior (spinal) parts

Question 7

What is the proximal attachment of the deltoid?

Answer 7

Lateral third of the clavicle

Question 8

What is the proximal attachment of the deltoid?

Answer 8

Deltoid tuberosity of humerus

Question 9

What is the innervation of the deltoid?

Answer 9

Axillary nerve (C5, C6)

Question 10

What is the arterial supply of the deltoid?

Answer 10

Posterior circumflex humeral artery

Question 11

What is the action of the clavicular part of the deltoid?

Answer 11

Flexes and medially rotates arm

Question 12

What is the action of the acromial part of the deltoid?

Answer 12

Abducts arm- takes over from supraspinatus, which abducts the first 15º

Question 13

What is the action of the spinal part of the deltoid?

Answer 13

It extends and laterally rotates the arm

Question 14

What does the teres major form?

Answer 14

The inferior border of the quadrangular space

Question 15

What is the quadrangular space?

Answer 15

The ‘gap’ that the axillary nerve and posterior circumflex humeral artery pass through to reach the posterior scapula region

Question 16

What is the proximal attachment of the teres major?

Answer 16

Posterior surface of the inferior angle of the scapula

Question 17

What is the distal attachment of the teres major?

Answer 17

Medial lip of intertubercular sulcus of humerus

Question 18

What is the innervation of the teres major?

Answer 18

Lower subscapular nerve (C5, C6)

Question 19

What is the arterial supply of the teres major?

Answer 19

Circumflex scapular artery

Subscapular artery

Question 20

What is the action of the teres major?

Answer 20

Adducts and medially rotates the arm

Question 21

Where do the rotator cuff muscles originate from?

Answer 21

The scapula

Question 22

What do the rotator cuff muscles attach to?

Answer 22

The humeral head

Question 23

What do the rotator cuff muscles collectively do?

Answer 23

The resting tone of these muscles acts to ‘pull’ the humeral head into the glenoid fossa, giving the glenohumeral joint a lot of additional stability

Question 24

What is the proximal attachment of the supraspinatus?

Answer 24

Supraspinous fossa of the scapula

Question 25

What is the distal attachment of the supraspinatus?

Answer 25

Superior facet of the greater tubercle of the humerus

Question 26

What is the innervation of the supraspinatus?

Answer 26

Suprascapular nerve (C4, C5, C6)

Question 27

What is the arterial supply of the supraspinatus?

Answer 27

Suprascapular artery

Question 28

What is the muscle action of the supraspinatous?

Answer 28

Initiates (0-15º) and assists the deltoid (15-90º) in abduction of the arm Acts with rotator cuff muscles

Question 29

What is the proximal attachment of the infraspinatus?

Answer 29

Infraspinous fossa of scapula

Question 30

What is the distal attachment of the infraspinatus?

Answer 30

Middle facet of the greater tubercle of humerus

Question 31

What is the innervation of the infraspinatus?

Answer 31

Suprascapular nerve (C5, C6)

Question 32

What is the arterial supply of the infraspinatus?

Answer 32

Circumflex scapular artery  | Suprascapular artery

Question 33

What is the action of the infraspinatus?

Answer 33

Laterally rotates the arm  | Acts with the rotator cuff muscles

Question 34

What is the proximal attachment of the subscapularis?

Answer 34

Subscapular fossa (most of anterior surface of scapula)

Question 35

What is the distal attachment of the subscapularis?

Answer 35

Lesser tubercle of humerus

Question 36

What is the innervation of the subscapularis?

Answer 36

Upper and lower subscapular nerves (C5, C6, C7)

Question 37

What is the arterial supply of the subscapularis?

Answer 37

Subscapular artery

Question 38

What is the action of the subscapularis?

Answer 38

Medially rotates arm | As part of rotator cuff, helps hold head of humerus in glenoid cavity

Question 39

What is the proximal attachment of the teres minor?

Answer 39

Middle part of lateral border of scapula

Question 40

What is the distal attachment of the teres minor?

Answer 40

Inferior facet of greater tubercle of humerus

Question 41

What is the innervation of the teres minor?

Answer 41

Axillary nerve (C5, C6)

Question 42

What is the arterial supply of the teres minor?

Answer 42

Circumflex scapular artery | Posterior circumflex humeral artery

Question 43

What is the action of the teres minor?

Answer 43

Laterally rotates arm  | Acts with rotator cuff muscles

Question 44

What does rotator cuff tendonitis refer to?

Answer 44

Inflammation of the tendons of the rotator cuff muscles

Question 45

What does rotator cuff tendonitis occur due to?

Answer 45

Secondary to repetitive use of the shoulder joint

Question 46

What is the muscle most commonly affected in rotator cuff tendonitis?

Answer 46

Supraspinatus

Question 47

Why is the supraspinatus the muscle most commonly affected in rotator cuff tendonitis?

Answer 47

During abduction, it ‘rubs’ against the coraco-acromial arch, which over time causes inflammation and degenerative changes in the tendon itself

Question 48

What does treatment of rotator cuff tendonitis involve?

Answer 48

Conservative treatment includes rest, analgesia and physiotherapy In more servere cases, steroid injections and surgery can be considered