Upper Limb 1 Station 4 - Rotator Cuff Muscles

Question 1

What muscle is on the anterior surface of the scapula?

Answer 1

Subscapularis

Question 2

What muscles make up the rotator cuff?

Answer 2

Subscapularis
Supraspinatus
Infraspinatus
Teres minor

Question 3

What movement of what joint is generated by the rotator cuff muscles?

Answer 3

Glenohumeral joint
Abduction
Lateral and medial rotation

Question 4

Where do the rotator cuff muscles extend from and to?

Answer 4

From scapula to humerus

Question 5

What is the most important role of the rotator cuff muscles.

Answer 5

Stabilisation of the joint not the movement aspect

Question 6

Deltoid origin and insertion?

Answer 6

Origin - from the lateral third of the clavicle, the acromion and the spine of the scapula

Insertion - attaches to the deltoid tuberosity on the humerus

Question 7

Where is the deltoid tuberosity on the humerus?

Answer 7

Lateral aspect roughly in middle

Question 8

Ant. fibres of the deltoid action on shoulder joint?

Answer 8

Flexion

Medial rotation

Question 9

Lateral deltoid/middle fibres action?

Answer 9

Abduction of shoulder joint

Question 10

Pos. fibres of deltoid action?

Answer 10

Extension and lateral rotation

Question 11

Deltoid nerve supply?

Answer 11

Axillary nerve

Question 12

What injury is the axillary nerve often trapped and injured in?

Answer 12

Dislocation of shoulder

Question 13

Where would you test for loss of sensation if the axillary nerve was damaged and why here?

Answer 13

Regimental badge area - C5 dermatome - because its a mixed nerve

Question 14

Where does the pec major fibres originate?

Answer 14

Medial 1/3rd of clavicle, the sternum and ribs (lower 3?)

Question 15

What does the pec major do to the shoulder joint?

Answer 15

Adducts and medially rotates (think of pec flies)

Question 16

What is the triangular space below the clavicle, between the deltoid and pec major muscles called? Which vein is found here and what is that vein used for?

Answer 16

Deltopectoral triangle

Subclavian vein - used for central lines

Question 17

What does the serratus anterior muscle do?

Answer 17

Protraction of the scapula

Also stabilises the scapula during limb movements - pulling it closer to the thoracic wall

Question 18

Nerve supply of the serratus anterior?

Answer 18

Long thoracic nerve

Question 19

What clinical sign is seen when the long thoracic nerve is injured? Why? What procedures have a high risk of causing this?

Answer 19

Winged scapula - scapula “wings” out medially due to paralysis of the serratus anterior muscle no longer stabilizing it

Radical mastectomies that involve removing the ax. lymph nodes

Question 20

Superior traps action on scapula?

Answer 20

Elevate

Question 21

Middle traps action on scapula?

Answer 21

Retract

Question 22

Inferior traps action on scapula

Answer 22

Depress

Question 23

Trapezius innervation? Why is this unusual?

Answer 23

Accessory nerve - cranial nerve

Question 24

Teres major’s action on shoulder joint?

Answer 24

Adducts

Medially rotates

Question 25

Latissimus dorsi action on shoulder joint?

Answer 25

Extension
Adduction
Medial rotation

Question 26

What muscle(s) cause flexion at the shoulder joint?

Answer 26

Ant. deltoid

Question 27

What muscles cause extension?

Answer 27

Latissimus dorsi

Posterior deltoid

Question 28

Adduction of shoulder is caused by the…

Answer 28

Teres major
Latissimus dorsi
Pec major

Question 29

Abduction of the shoulder is caused by the…

Answer 29

Middle deltoid

Supraspinatus

Question 30

Medial rotation caused by

Answer 30

Latissimus dorsi
Teres major
Pec major
Subscapularis

Question 31

Lateral rotation is caused by

Answer 31

Teres minor

Infraspinatus