2 Muscles of the shoulder

Question 1

What is the resting function of the rotator cuff muscles?

Answer 1

To pull head of humerus into glenoid cavity

Question 2

What are the four rotator cuff muscles?

Answer 2

Supraspinatus
Infraspinatus
Teres minor
Subscapularis

Question 3

What movemenys of the glenohumeral jiont are generated by the rotator cuff muscles?

Answer 3

Abduction adduction
Lateral medial rotation

Question 4

Where does subscapularis attach?

Answer 4

Subscapularis fossa on scapula to lesser tubercle of humerus

Question 5

What is the innervation of the subscapularis?

Answer 5

Upper and lower subscapular nerves

Question 6

What is the function of subscapularis?

Answer 6

To medially rotate the arm

Question 7

Where does the supraspinatus attach?

Answer 7

Supraspinous fossa of scapula to greater tubercle of humerus

Question 8

What is the innervation of supraspinatus?

Answer 8

Suprascapular nerve

Question 9

What is the function of the supraspinatus?

Answer 9

Abduct arm from 0-15°
Assists deltoid in abduction from 15-90°

Question 10

Where does the infraspinatus attach?

Answer 10

Infraspinous fossa of scapula to greater tubercle of humerus

Question 11

What is the innervation of infraspinatus?

Answer 11

Suprascapular nerve

Question 12

What is the function of the infraspinatus?

Answer 12

Lateral rotation of arm

Question 13

Where does teres minor attach?

Answer 13

Posterior surface of scapula adjacent to lateral border to greater tubercle of humerus

Question 14

What is the innervation of teres minor?

Answer 14

Axillary nerve

Question 15

What is the function of teres minor?

Answer 15

Laterally rotate arm

Question 16

What are the three divisions of the deltoid?

Answer 16

Anterior middle posterior

Question 17

Where does the deltoid attach?

Answer 17

Scapula and clavicle to deltoid tuberosity of humerus

Question 18

What is the innervation of the deltoid?

Answer 18

Axillary nerve

Question 19

What is the function of the deltoid?

Answer 19

Anterior - flexion of arm at shoulder
Middle - abduction of arm 15-90°
Posterior - extension of arm at shoulder

Question 20

Where does teres major attach?

Answer 20

Posterior surface of inferior angle of scapula to intertubercular groove of humerus

Question 21

What is the innervation of teres major?

Answer 21

Lower subscapular nerve

Question 22

What is the function of teres major?

Answer 22

Adducts the shoulder
Medially rotates the arm

Question 23

What are the intrinsic muscles of the shoulder?

Answer 23

Muscles that originate from scapula and/or clavicle and attch to humerus

Question 24

What are the six intrinsic muscles of the shoulder?

Answer 24

Supraspinatus
Infraspinatus
Teres minor
Subscapularis
Deltoid
Teres major

Question 25

What is the common injury which results in trapped axillary nerve?

Answer 25

Fracture of surgical necj of humerus
Skin over shoulder (officers badge) would have loss of sensation

Question 26

What are extrinsic muscles of the shoulder?

Answer 26

Muscles that originate from torso and attach to bones of the shoulder
Also known as superficial back muscles

Question 27

What are the layers of extrinsic muscles of the shoulder?

Answer 27

Superficial - trapezius, latissimus dorsi
Deep - levator scapulae, rhomboid major, rhomboid minor