Posterior axio-appendicular skeleton muscles (JO)

Question 1

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 1

Trapezius (superficial)
Origin: Medial ⅓ of superior nuchal line; external occipital
protuberance, nuchal ligament, and spinous
processes of the C7-T12 vertebrae
Insertion: Lateral ⅓ of clavicle, acromion, and spine of the
scapula
Innervation: Spinal root of accessory nerve CN XI (motor);
cervical nerves C3 and C4 (pain and
proprioception)
Action: Elevates (superior fibers), depresses (inferior
fibers), retracts (middle fibers), and upwardly
rotates scapula

Question 2

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 2

Latissimus Dorsi (superficial)
Origin: Spinous processes of inferior 6 thoracic vertebrae,
thoracolumbar fascia, iliac crest, and the inferior 3-
4 ribs
Insertion: Floor of intertubercular sulcus of the humerus
Innervation: Thoracodorsal nerve
Action: Extends, adducts, and medially rotates the GH joint

Question 3

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 3

Levator Scapulae (deep)
Origin: Posterior tubercles of the transverse processes of the C1-C4 vertebrae
Insertion: Superior part of the medial border of scapula
Innervation: Dorsal scapular nerve and C3-C4 spinal nerves
Action: Elevates and downwardly rotates the scapula

Question 4

Name this muscle:
State its Origin(s), Insertion(s), Innervation(s), and Action(s)

Answer 4

Rhomboid minor and major (deep)
Origin: Minor: nuchal ligament and the spinous processes
of the C7-T1 vertebrae. Major: spinous processes of
T2-T5 vertebrae
Insertion: Minor: medial border at level of the spine
Major: medial border of the scapula from spine to the
inferior angle
Innervation: Dorsal scapular nerve
Action: Retract and downwardly rotates the scapula; fixes
scapula to the thoracic wall