Upper Limb Muscles of the Shoulder Region

Question 1

What are the superficial muscles of the extrinsic shoulder?

Answer 1

Trapezius and latissimus dorsi.

Question 2

What are the deep muscles of the extrinsic shoulder?

Answer 2

Levator scapulae and rhomboid minor and major.

Question 3

What are the proximal attachments of the trapezius?

Answer 3

Medial third of superior nuchal line, external occipital proturberance, nuchal ligament, spinous processes of C7-T12 vertebrae.

Question 4

What are the distal attachments of the trapezius?

Answer 4

Lateral third of clavicle, acromion and spine of scapula.

Question 5

What is the trapezius innervated by?

Answer 5

Spinal accesssory nerve and C3, C4 spinal nerves.

Question 6

What is the arterial supply of the trapezius?

Answer 6

Transverse cervical artery.

Question 7

What is the action of the trapezius?

Answer 7

Descending part elevates, ascending part depresses and the middle part retracts scapula. Descending and ascending parts act together to rotate the glenoid cavity superiorly.

Question 8

What are the proximal attachments of the latissimus dorsi?

Answer 8

Spinous processes of inferior 6 thoracic vertebrae, thoracolumbar fascia, iliac crest, and inferior 3/4 ribs.

Question 9

What is the distal attachment of the latissimus dorsi?

Answer 9

Floor of the intertubercular sulcus of humerus.

Question 10

What is the latissimus dorsi innervated by?

Answer 10

Thoracodorsal nerve (C6, C7, C8).

Question 11

What is the arterial supply of the latissimus dorsi?

Answer 11

Thoracodorsal artery.

Question 12

What is the action of the latissimus dorsi?

Answer 12

Extends, adducts, and medially rotates humerus, raises body towards arms during climbing.

Question 13

What are the proximal attachments of the levator scapulae?

Answer 13

Posterior tubercles of transverse processes of C1-C4 vertebrae.

Question 14

What is the distal attachment of the levator scapulae?

Answer 14

Medial border of scapula superior to root of scapula spine.

Question 15

What is the levator scapulae innervated by?

Answer 15

Dorsal scapula (C4, C5) and cervical (C3, C4) nerves.

Question 16

What is the arterial supply of the levator scapulae?

Answer 16

Transverse cervical artery and ascending cervical artery.

Question 17

What is the action of the levator scapulae?

Answer 17

Elevates scapula and rotates its glenoid cavity inferiorly by rotating scapula.

Question 18

What is the proximal attachment of the rhomboid major?

Answer 18

Spinous processes of T2-T5 vertebrae.

Question 19

What is the distal attachment of the rhomboid major?

Answer 19

Medial border of the scapula from level of spine to inferior angle.

Question 20

What is the rhomboid major innervated by?

Answer 20

Dorsal scapula nerve (C4, C5).

Question 21

What is the arterial supply of the rhomboid major?

Answer 21

Dorsal scapular artery.

Question 22

What is the action of the rhomboid major?

Answer 22

Retract the scapula and rotate its glenoid cavity inferiorly, fix scapula to thoracic wall.

Question 23

What are the proximal attachments of the rhomboid minor?

Answer 23

Nuchal ligament and spinous processes of C7 and T1 vertebrae.

Question 24

What is the distal attachment of the rhomboid minor?

Answer 24

Smooth triangular area at medial end of scapula spine.

Question 25

What is the rhomboid minor innervated by?

Answer 25

Dorsal scapular nerve (C4, C5).

Question 26

What is the arterial supply of the rhomboid minor?

Answer 26

Dorsal scapular artery.

Question 27

What is the action of the rhomboid minor?

Answer 27

Retract the scapula and rotate its glenoid cavity inferiorly, fix scapula to thoracic wall.

Question 28

How can the accessory nerve be tested?

Answer 28

By assessing the trapezius function, ask the patient to shrug their shoulders.

Question 29

What are the intrinsic shoulder muscles?

Answer 29

Scapulohumeral muscles: deltoid, supraspinatous, infraspinatous, teres minor, teres major, subscapularis.

Question 30

What are the proximal attachments of the deltoid?

Answer 30

Lateral third of clavicle, acromion and spine of scapula.

Question 31

What is the distal attachment of the deltoid?

Answer 31

Deltoid tuberosity of the humerus.

Question 32

What is the deltoid innervated by?

Answer 32

Axillary nerves (C5, C6).

Question 33

What is the arterial supply of the deltoid?

Answer 33

Posterior circumflex humeral artery.

Question 34

What is the action of the deltoid?

Answer 34

Clavicular part flexes and medially rotates arm. Acromial part abducts arm. Spinal part extends and laterally rotates arm.

Question 35

What is the proximal attachment of the supraspinatous?

Answer 35

Supraspinous fossa of scapula.

Question 36

What is the distal attachment of the supraspinatous?

Answer 36

Superior facet of greater tubercle of humerus.

Question 37

What is the supraspinatous innervated by?

Answer 37

Suprascapular nerve (C4, C5, C6).

Question 38

What is the arterial supply of the supraspinatous?

Answer 38

Suprascapular artery.

Question 39

What is the action of the supraspinatous?

Answer 39

Initiates and assists deltoid in abduction of arm and acts with rotator cuff muscles.

Question 40

What is the proximal attachment of the infraspinatous?

Answer 40

Infraspinous fossa of scapula.

Question 41

What is the distal attchament of the infraspinatous?

Answer 41

Middle facet of greater tubercle of humerus.

Question 42

What is the infraspinatous innervated by?

Answer 42

Suprascapular nerve (C5, C6).

Question 43

What is the arterial supply of the infraspinatous?

Answer 43

Circumflex scapular artery and suprascapular artery.

Question 44

What is the action of the infraspinatous?

Answer 44

Laterally rotates arm and acts with rotator cuff muscles.

Question 45

What is the proximal attachment of the teres minor?

Answer 45

Middle part of lateral border of scapula.

Question 46

What is the distal attachment of the teres minor?

Answer 46

Inferior facet of greater tubercle of humerus.

Question 47

What is the teres minor innervated by?

Answer 47

Axillary nerve (C5, C6).

Question 48

What is the arterial supply of the teres minor?

Answer 48

Circumflex scapular artery and posterior circumflex humeral artery.

Question 49

What is the action of the teres minor?

Answer 49

Laterally rotates arm and acts with rotator cuff muscles.

Question 50

What is the proximal attachment of the teres major?

Answer 50

Posterior surface of inferior angle of the scapula.

Question 51

What is the distal attachment of the teres major?

Answer 51

Medial lip of intertubercular sulcus of humerus.

Question 52

What is the teres major innervated by?

Answer 52

Lower subscapular nerve (C5, C6).

Question 53

What is the arterial supply of the teres major?

Answer 53

Circumflex scapular artery, subscapular artery.

Question 54

What is the action of the teres major?

Answer 54

Adducts and medially rotates arm.

Question 55

What is the proximal attachment of the subscapularis?

Answer 55

Subscapular fossa.

Question 56

What is the distal attachment of the subscapularis?

Answer 56

Lesser tubercle of humerus.

Question 57

What is the subscapularis innervated by?

Answer 57

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

Question 58

What is the arterial supply for the subscapularis?

Answer 58

Subscapular artery.

Question 59

What is the action of the subscapularis?

Answer 59

Medially rotates arm, as part of the rotator cuff, helps hold head of humerus in glenoid cavity.

Question 60

What are the four rotator cuff muscles?

Answer 60

Supraspinatus, infraspinatus, supscapularis and teres minor.

Question 61

What is the function of the rotator cuff muscles?

Answer 61

To pull the humeral head into the glenoid fossa to give the glenohumeral joint more stability.

Question 62

What is rotator cuff tendonitis?

Answer 62

Inflammation of the tendons of the rotator cuff muscles.

Question 63

What causes rotator cuff tendonitis?

Answer 63

Repetitive use of the shoulder joint.

Question 64

Which of the rotator cuff muscles is most commonly affected by rotator cuff tendonitis?

Answer 64

Supraspinatus. In abduction, it rubs against the coracoacromial arch and this causes inflammation and degeneration in the tendon eventually.

Question 65

How is rotator cuff tendonitis treatment?

Answer 65

Rest, analgesia, and physiotherapy. Steroid injections and surgery can be used in severe cases.