(Module 2B) Muscles of the Back

Which 4 muscles make up Extrinsic, Superficial muscles of the back?

Trapezius, Latissimus dorsi, Rhomboid major, Rhomboid minor

What is the major action of the Trapezius?

Moves the shoulder region

What is the major action of the Latissimus dorsi?

Moves the upper limb

What is the major action of the Rhomboid major/minor?

Moves and stabilizes the shoulder region

Which 2 muscles make up the Extrinsic, Intermediate muscles?

Serratus posterior superior, Serratus posterior inferior

What is the major action of the Serratus posterior superior?

Elevates ribs

What is the major action of the Serratus posterior inferior?

Depresses ribs

What are the 3 Intrinsic back muscles (of the Erector Spinae group)?

Iliocostalis, Longissimus, Spinalis

Iliocostalis, Longissimus, and Spinalis belong in the _____ muscle group.

Erector Spinae

Describe the relative position of Iliocostalis, Longissimus, and Spinalis to one another.

Iliocostalis = outermost (more lateral)

Longissimus = intermediate / in the middle

Spinalis = innermost (more medial)

What is the major action of the Iliocostalis?

Extend and laterally flex vertebral column

What is the major action of the Longissimus?

Extend and laterally flex vertebral column/head

What is the major action of the Spinalis?

Extend vertebral column

Extrinsic back muscles primarily act on the _____ or _____.

upper limb; ribs

The Serratus posterior muscles are intermediate extrinsic muscles associated with _____.

movement of the ribs