Shoulder Girdle Muscles

Question 1

Upper Trapezius

Answer 1

O: Occipital bone, nuchal ligament on upper cervical spinous processes.

I: Outer 1/3 of the clavicle, acromion process

A: Scapular elevation, upward rotation

N: Spinal accessory n. (CN XI), C3-C4 sensory component

Question 2

Middle Trapezius

Answer 2

O: Spinous processes C7-T3

I: Scapular spine

A: Scapular retraction

N: Spinal accessory n. (CN XI), C3-C4 sensory component

Question 3

Lower Trapezius

Answer 3

O: Spinous processes of middle and lower thoracic vertebrae

I: Base of scapular spine

A: Scapular depression, upward rotation

N: Spinal accessory n. (CN XI), C3-C4 sensory component

Question 4

Levator Scap.

Answer 4

O: Transverse processes C1-C4

I: Vertebral border of scapula between superior angle and spine

A: Scapular elevation, downward rotation

N: C3-C4 spinal nerve roots, Dorsal scapular n. (C5)

Question 5

Rhomboids (Rhomboid Major, Rhomboid Minor)

Answer 5

O: Spinous processes C7-T5

I: Vertebral border of scapula between spine and inferior angle

A: Scapular retraction, elevation, downward rotation

N: Dorsal scapular n. (C5)

Question 6

Serratus Anterior

Answer 6

O: Lateral surface of ribs 1-8

I: Vertebral border of scapula, anterior surface

A: Scapular protraction, upward rotation

N: Long thoracic n. (C5, C6, C7)

Question 7

Pectoralis Minor

Answer 7

O: Anterior surface, ribs 3-5

I: Coracoid process of scapula

A: Scapular depression, protraction, downward rotation, tilt

N: Medial pectoral n. (C8, T1)

Question 8

What are the primary muscles involved in scapular retraction?

Answer 8

Middle trapezius, rhomboids

Question 9

What are the primary muscles involved in scapular protraction?

Answer 9

Serratus anterior, pectoralis minor

Question 10

What are the primary muscles involved in scapular elevation?

Answer 10

Upper trapezius, levator scap., rhomboids

Question 11

What are the primary muscles involved in scapular depression?

Answer 11

Lower trapezius, pectoralis minor

Question 12

What are the primary muscles involved in scapular upward rotation?

Answer 12

Upper and lower trapezius, serratus anterior

Question 13

What are the primary muscles involved in scapular downward rotation?

Answer 13

Rhomboids, levator scapula, pectoralis minor

Question 14

What is the primary muscle involved in scapular tilting?

Answer 14

Pectoralis minor

Question 15

What are the four muscles of the Rotator Cuff?

Answer 15

Supraspinatus
Infraspinatus
Subscapularis
Teres Minor

Question 16

Anterior Deltoid

Answer 16

O: Lateral 1/3 of the clavicle

I: Deltoid tuberosity of humerus

A: Shoulder ABD., flexion, IR, and horizontal ADD.

N: Axillary n. (C5, C6)

Question 17

Middle Deltoid

Answer 17

O: Acromion process

I: Deltoid tuberosity of humerus

A: Shoulder ABD.

N: Axillary n. (C5, C6)

Question 18

Posterior Deltoid

Answer 18

O: Spine of scapula

I: Deltoid tuberosity of humerus

A: Shoulder ABD., extension, hyperextension, ER, horizontal ABD.

N: Axillary n. (C5, C6)

Question 19

Pectoralis Major

Answer 19

O: Sternum, Medial 1/3 of clavicle, Costal cartilage ribs 1-6

I: Lateral lip of bicipital groove of humerus

A: Shoulder ADD, IR, horizontal ADD.

N: Lateral and Medial Pectoral n. (C5, C6, C7, C8, T1)

Question 20

Latissimus Dorsi

Answer 20

O: Spinous processes T7-L5 via thoracolumbar fascia, posterior surface of sacrum, iliac crest, and lower 3 ribs.

I: Medial floor of bicipital groove of humerus

A: Shoulder ext., ADD., IR, hyperextension

N: Thoracodorsal n. (C6, C7, C8)

Question 21

Teres Major

Answer 21

O: Inferior axillary border of scapula near inferior angle

I: Medial lip of bicipital groove on anterior surface of humerus

A: Shoulder extension, ADD., IR

N: Lower subscapular n. (C5, C6, C7)

Question 22

Supraspinatus

Answer 22

O: Supraspinous fossa of scapula

I: Greater tubercle of humerus

A: Shoulder ABD.

N: Suprascapular n. (C5, C6)

Question 23

Infraspinatus

Answer 23

O: Infraspinous fossa of scapula

I: Greater tubercle of humerus

A: Shoulder ER, horizontal ABD.

N: Suprascapular n. (C5, C6)

Question 24

Teres Minor

Answer 24

O: Axillary border of scapula

I: Greater tubercle of humerus

A: Shoulder ER, horizontal ABD.

N: Axillary n. (C5, C6)

Question 25

Subscapularis

Answer 25

O: Subscapular fossa of the scapula I: Lesser tubercle of the humerus A: Shoulder IR N: Upper and lower subscapular n. (C5, C6)

Question 26

Coracobrachialis

Answer 26

O: Coracoid process of the scapula I: Medial surface of the humerus near the midpoint A: Stabilizes the shoulder joint N: Musculocutaneous n. (C5, C6, C7)

Question 27

What are the primary muscles involved in performing shoulder flexion?

Answer 27

Anterior deltoid, clavicular head of pectoralis major

Question 28

What are the primary muscles involved in performing extension?

Answer 28

Posterior deltoid, latissimus dorsi, teres major, sternal head of pectoralis major

Question 29

What are the primary muscles involved in shoulder hyperextension?

Answer 29

Latissimus dorsi, posterior deltoid

Question 30

What are the primary muscles involved in ADDuction?

Answer 30

Pectoralis major, teres major, latissimus dorsi

Question 31

What are the primary muscles involved in shoulder ABDuction?

Answer 31

Deltoid, supraspinatus

Question 32

What are the primary muscles involved in shoulder horizontal ABDuction?

Answer 32

Posterior deltoid, infraspinatus, teres minor

Question 33

What are the primary muscles involved in horizontal ADDuction?

Answer 33

Pectoralis major, anterior deltoid

Question 34

What are the primary muscles involved in shoulder ER?

Answer 34

Infraspinatus, teres minor, posterior deltoid

Question 35

What are the primary muscles involved in shoulder IR?

Answer 35

Subscapularis, latissimus dorsi, teres major, pectoralis major, anterior deltoid