Superficial Muscles of Back

Question 1

Trapezius

Answer 1

O: 1. Medial Third of superior nuchal line
2. External Occipital Protuberance
3. Nuchal Ligament
4. Spinous Processes of C7-T12 vertebrae
I: 1. Lateral third of clavicle
2. Acromion and spine of scapula
N: 1. Spinal Accessory Nerve (XI)
2. C3, C4
A: 1. Descending part elevates
2. Ascending part depresses
3. Middle part (or all parts together) retract scapula
4. Descending and ascending parts act together to rotate glenoid cavity superiorly
5. Superior fibers elevate pectoral girdle and maintain level shoulders against gravity/resistance

Question 2

Latissimus Dorsi

Answer 2

O: 1. Spinous Processes of inferior 6 thoracic vertebrae
2. Thoracolumbar Fascia
3. Iliac Crest
4. Inferior 3 or 4 ribs
I: Floor of intertubercular surface of humerus
N: Thoracodorsal Nerve C6, C7, C8
A: 1. Extends, Adducts, and medially rotates humerus
2. Raises body toward arms when climbing

Question 3

Rhomboid Major

Answer 3

O: Spinous processes of T2-T5 vertebrae
I: Medial border of scapula from level of spine to inferior angle
N: Dorsal Scapular Nerve
A: 1. Retract scapula
2. Rotate scapula to depress glenoid cavity
3. Fix scapula to thoracic wall

Question 4

Rhomboid Minor

Answer 4

O: 1. Nuchal Ligament
2. Spinous processes of C7 and T1 vertebrae
I: Smooth triangular area at medial end of scapular spine
N: Dorsal Scapular Nerve
A: 1. Retract scapula
2. Rotate scapula to depress glenoid cavity
3. Fix scapula to thoracic wall

Question 5

Levator Scapulae

Answer 5

O: Posterior tubercles of transverse processes of C1-C4 vertebrae
I: 1. Medial Border of Scapula superior to root of scapular spine
N: Dorsal Scapular Nerve
A: 1. Elevate scapula
2. Tilts glenoid cavity inferiorly by rotating scapula