Deep Muscles Of The Back

Front 1

Erector spinae
-iliocostalis
-longissimus
-spinalis

Back 1

Origin: vertebral column, ilium, ribs
Insertion: ribs, vertebral column, occipital and temporal bones
Action: extends and rotates vertebral column and head

Front 2

Multifidus

Back 2

Origin: vertebra C4-L5, sacrum, ilium
Insertion: vertebral column
Action: extends and rotates vertebral column

Front 3

Quadratus lumborum

Back 3

Origin: posterior iliac crest
Insertion: T12 and L1-4, rib 12
Action: extends and abducts vertebral column

Front 4

Rhomboideus major

Back 4

Origin: spines of T2-5
Insertion: lower 1/3 of vertebral border of scapula
Action: adducts scapula

Front 5

Rhomboideus minor

Back 5

Origin: ligamentum nuchae and spines C7-T1
Insertion: vertebral border of scapula at scapular spine
Action: adducts scapula

Front 6

Splenius

Back 6

Origin: ligamentum nuchae, C7-T6
Insertion: C2-4, occpital and temporal bone
Action: extends and rotates head

Front 7

Semispinalis

Back 7

Origin: C7-T12
Insertion: occiptial bone and T1-4
Action: extends head and vertebral column, rotates vertebral column