Back mm 1

Question 1

Trapezius m.

Answer 1

Superficial layer
Extrinsic
O: occipital bone (medial third of superior nuchal line), EOP, Ligamentum Nuchae SPs of C7, SPs of all thoracic vertebrae
I: lateral third of clavicle, acromion and spine of scapula
Action: Ascending fibers and Descending fibers rotate scapula superiorly/ Descending fibers = elevation of scapula, SB of Cxspine, ROT of Cxspine ipsilaterally, EXT of Cxspine/ Middle = Retraction/ Ascending fibers = depression
INNE; Accessory n (cranial XI - motor), C3, C4 nerve roots - proprioreceptive fibers

Question 2

Rhomboid Major m.

Answer 2

Superficial Layer
Extrinsic
Superficial Layer
Extrinsic
O: SPs of T2-T5
I: Medial border of scapula from spine to inferior angle
Action: Retraction/ rotates scapula inferiorly/ fixes scapula against the thoracic cage
INNE: Dorsal Scapular n. (C5 nerve root)

Question 3

Rhomboid Minor

Answer 3

Superficial Layer
Extrinsic
O: Ligamentum Nuchae SPs of C7-T1
I: superior part of medial border of scapula
Action: Retraction/ rotates scapula inferiorly/ fixes it against the thoracic wall
INNE: Dorsal Scapular n (C5)

Question 4

Levator Scapula

Answer 4

Superficial Layer
Extrinsic
O: Posterior Tubercles of transverse processes of C1-C4
I: Superior angle of scapula
Action: Elevates scapula/ rotates scapula downawards by rotating the scapula/ SB of neck ipsilaterally/ Rotates neck ipsilaterally
INNE: Dorsal Scapular (C5) and C3 and C4

Question 5

Latissimus Dorsi

Answer 5

Superficial Layer
Extrinsic
O: SPs of T6-T12, thoracolumbar fascia, inferior 3-4 ribs, iliac crest
I: floor of intertubercular sulcus of humerus
Action: climbing/ EXT/ ADD/ IR
INNE: Thoracodorsal n. (C6-C8)