Scapular Shape/Superficial back Muscles & Deep Muscles of the Back/Erector spinae m.

Unit 3

the shapes of the back

• trapezius

• rhomboid minor

• rhomboid major

• levator scapulae

all of the shape m. (besides trapezius) are innervated by

dorsal scapular n.

the trapezius m. is innervated by

accessory n. (CN XI)

what is the action(s) of both rhomboid major and minor muscles?

retracts scapula

action(s) of levator scapulae m.

elevates scapula

action(s) of trapezius m.

• elevate scapula

• retracts scapula

• depresses scapula

what muscle is shown here

trapezius

what muscle is highlighted in green here

levator scapulae

A

trapezius m.

B

levator scapulae m.

C

rhomboid minor m.

D

rhomboid major m.

the erector spinae m./deep muscles of the back include

• iliocostalis m.

• longissimus m.

• spinalis m.

I Love Standing

iliocostalis, longissimus, spinalis (L→M)

the bilateral action(s) of all the erector spinae m. include:

extend head & vertebral column

the unilateral action(s) of all the erector spinae m. include:

lateral flexion of head & vertebral column

all the erector spinae m. are innervated by

dorsal rami n.

lateral most muscle shown is

iliocostalis m.

muscle in between is

longissiumus m.

medial most muscle

spinalis m.