superficial back/intrinsic shoulder muscles

Question 1

erector spinae

Answer 1

Orientation: Posterior Origin: illiac crest, sacrum, transverse and spinous process,
Insertion: ribs Nerve: Dorsal Rami
Function:Bilateral contraction-extension of the spine and head, Unilateral contraction-ipsilateral bending & ipsilateral rotation of spine.

Question 2

trapezius

Answer 2

Orientation: Posterior Origin: External occipital protuberance (EOP), spinous processes down to T12 Insertion: Lateral 1/3 of the clavicle, medial side of the cromion process, and upper crest and tuvercle of the scapular spine. Nerve: Accessory nerve
Function: retraction, superior rotation, elevation and depression of the scapula

Question 3

rhomboid major

Answer 3

Orientation: Posterior Origin: Spinous process of vertibrae T2-T5 Insertion: Medial border of scapula Nerve: Dorsal scapular nerve (C4,5) Function: Stabilization, Retracts, elevation and internal rotation of scapula

Question 4

rhomboid minor

Answer 4

Orientation: Posterior Origin: Spinous process of C7 and T1 Insertion: Medial border of scapula Nerve: Dorsal scapula (C4,5) Function: Stabilization, Retraction, elevation and interal rotatation of scapula

Question 5

levator scalpulae

Answer 5

Orientation: Posterior Origin: Transverse process of vertebrae C1-C4 Insertion: Superior angle of medial borader of scapula Nerve: Dorsal scapular nerve
Function: Elevates, retracts, and rotates scapula; laterally flexes of head and neck

Question 6

latissimus dorsi

Answer 6

Orientation: Sides Origin: Spinous process T7-L5, sacrum and iliac crest Insertion: crest of the lessor tubercle of humerous and intertubercular goove
Nerve: Thoracodorsal Function: Adduction, medial rotation, and extention of the arm. Aids in respiration

Question 7

serratus anterior

Answer 7

Orientation: anterior Origin: Antero lateral aspect of upper 8-9 ribs Insertion: Medial border of scapula Nerve: Long thoracic nerve
Function: Scapular abduction, upward rotation of lateral angle