Scapular & Rotator Cuff Muscles

Question 1

Supplies a cuff around the glenohumeral joint to stabilize the head of the humerus in the glenoid fossa and control the movements at this joint.

Answer 1

Rotator Cuff

Question 2

What are the 4 muscles of the rotator cuff?

Answer 2

1) Supraspinatus
2) Infraspinatus
3) Teres Minor
4) Subscapularis

Question 3

Which 2 scapular muscles are not part of the rotator cuff?

Answer 3

1) Deltoid
2) Teres Major

Question 4

Otherwise known as your shoulder cap and resembles an upside down triangle.

Answer 4

Deltoid

Question 5

What are the 3 heads of the deltoid muscle?

Answer 5

1) Anterior Head
2) Middle Head
3) Posterior Head

Question 6

Medial Attachment: anterolateral 1/3 of clavicle (anterior head), lateral acromion (middle head) and spine of scapula (posterior head)
Lateral Attachment: deltoid tuberosity

Answer 6

Deltoid

Question 7

What is the action of all the heads of the deltoid muscle?

Answer 7

G-H Abduction

Question 8

What are the 3 actions of the anterior head of the deltoid?

Answer 8

1) G-H Medial Rotation
2) G-H Flexion
3) G-H Horizontal Adduction

Question 9

What are the 3 actions of the posterior head of the deltoid?

Answer 9

1) G-H Lateral Rotation
2) G-H Extension
3) G-H Horizontal Abduction

Question 10

What does SItS stand for?

Answer 10

Supraspinatus
Infraspinatus
Teres Minor
Subscapularis

Question 11

The head of the humerus can be separated from the glenoid fossa by ___ cm when the muscles are cut.

Answer 11

2.5 cm

Question 12

A muscle that fills the space above the spine of the scapula and travels deep to the acromion. It is vulnerable for impingement, which can cause tendonitis.

Answer 12

Supraspinatus

Question 13

Medial Attachment: supraspinous fossa
Lateral Attachment: superior facet of greater tubercle of humerus and G-H joint capsule

Answer 13

Supraspinatus

Question 14

What are the 2 actions of supraspinatus?

Answer 14

1) G-H Abduction (up to 90 degrees)
2) Scaption

Question 15

Which muscle stabilizes the G-H joint by tucking the head of the humerus into the glenoid fossa, so it doesn’t run into the acromion?

Answer 15

Supraspinatus

Question 16

Medial Attachment: infraspinous fossa
Lateral Attachment: middle facet of greater tubercle of humerus and G-H joint capsule

Answer 16

Infraspinatus

Question 17

What is the action of infraspinatus?

Answer 17

G-H External Rotation

Question 18

A small and cylindrical muscle with the same action as infraspinatus.

Answer 18

Teres Minor

Question 19

Medial Attachment: lateral middle border of scapula (between triceps and teres major)
Lateral Attachment: inferior facet of greater tubercle of humerus and G-H joint capsule

Answer 19

Teres Minor

Question 20

What is the action of teres minor?

Answer 20

G-H External Rotation

Question 21

Medial Attachment: subscapular fossa
Lateral Attachment: lesser tubercle of humerus and G-H joint capsule

Answer 21

Subscapularis

Question 22

What is the action of subscapularis?

Answer 22

G-H Internal Rotation

Question 23

Medial Attachment: posterior surface of inferior angle of scapula
Lateral Attachment: medial lip of bicipital groove

Answer 23

Teres Major

Question 24

What are the 3 actions of teres major?

Answer 24

1) G-H Internal Rotation
2) G-H Extension
3) G-H Adduction

Question 25

Which muscle has the same actions as latissimus dorsi?

Answer 25

Teres Major