Muscles of the Shoulder

Question 1

Trapezius Origin

5

Answer 1

• superior nuchal line
• external occipital protuberance
• medial margin of ligamentum nuchae
• spinous processes of C7 to T12
  & related supraspinous ligaments of C7 to T12

Question 2

Trapezius Insertion

3

Answer 2

• spine of scapula, sup. edge of crest
• acromion
• post. border of lateral 1/3 of clavicle

Question 3

Trapezius Innervation (Sensory)

Answer 3

Anterior rami of C3 & C4

Question 4

Trapezius Innervation (Motor)

Answer 4

Spinal part of accessory nerve (XI)

Question 5

Trapezius Functions

4

Answer 5

• elevator of scapula (= powerful)
• rotation of scapula, when abducting humerus > 90 degrees
• retraction of scapula (middle fibres)
• depression of scapula (lower fibres)

Question 6

Muscles of trapezius that retract the scapula

Answer 6

Middle fibres

Question 7

Muscles of trapezius that depress the scapula

Answer 7

Lower fibres

Question 8

When does the trapezius rotate the scapula?

Answer 8

When the humerus is being abducted above 90 degrees

Question 9

Deltoid Origin

3

Answer 9

• inf. edge of crest of spine of scapula
• lateral margin of the acromion
• ant. border of lateral 1/3 of clavicle

Question 10

Deltoid Insertion

1

Answer 10

Deltoid tuberosity of humerus

Question 11

Deltoid Innervation

Nerve & Spinal Levels

Answer 11

Axillary Nerve, C5 & C6

Question 12

Deltoid Functions

Answer 12

• arm abduction (major abductor) (initial 15 degrees = supraspinatus)
• arm flexion (clavicular fibres)
• arm extension (posterior fibres)

Question 13

Deltoid fibres that extend the arm?

Answer 13

Posterior fibres

Question 14

Deltoid fibres that flex the arm?

Answer 14

Clavicular fibres

Question 15

Major spinal segment innervating the deltoid?

Answer 15

C5

Question 16

Levator scapulae origin

2

Answer 16

• transverse process of C1 & C2

- posterior tubercles of transverse process of C3 & C4

Question 17

The levator scapulae originates from the transverse processes of which vertebrae?

Answer 17

C1 & C2

Question 18

The levator scapulae originates from the posterior tubercles on the transverse processes of which vertebrae?

Answer 18

C3 & C4

Question 19

Levator scapulae insertion

1

Answer 19

Post. surface of medial border of scapula (from Sup, angle to root of spine of scapula)

Question 20

Levator scapulae innervation

2, nerves and spinal segments

Answer 20

• branches of anterior rami of C3 & C4 spinal nerves

- branches of dorsal scapular nerve (C5)

Question 21

Which spinal levels innervate the levator scapulae?

Answer 21

C3, C4, C5

Question 22

What is the function of the levator scapulae?

Answer 22

Elevation of the scapula

Question 23

Rhomboid minor origin

2

Answer 23

• ligamentum nuchae (lower end)

- spinous processes of C7 to T1

Question 24

Rhomboid minor insertion

1

Answer 24

Posterior surface of medial border of scapula at the root of the spine of the scapula

Question 25

Rhomboid minor innervation

nerve and spinal segments

Answer 25

Dorsal Scapula Nerve (C4 & C5)

Question 26

Function of Rhomboid Minor

2

Answer 26

• Elevation of scapula

- Retraction of scapula

Question 27

Rhomboid Major origin

2

Answer 27

• Spinous processes of T2 - T5

& Intervening supraspinous ligaments

Question 28

Rhomboid Major insertion

1

Answer 28

Posterior surface of medial border of scapula (root of spine of scapula to inferior angle)

Question 29

Rhomboid Major innervation

nerve & spinal segments

Answer 29

Dorsal Scapula Nerve (C4 & C5)

Question 30

Function of Rhomboid Major

2

Answer 30

• Elevation of scapula

- Retraction of scapula

Question 31

Which 3 muscles insert into the posterior surface of the Medial Border of the Scapula? Where do they insert along the border?

Answer 31

1. Levator Scapulae (Sup. Angle - Root of Spine)
2. Rhomboid Minor (Root of Spine)
3. Rhomboid Major (Root of Spine - Inf. Angle)

Question 32

Rotator Cuff Muscles

4

Answer 32

Subscapularis
Supraspinatus
Infraspinatus
Teres Minor