muscles of the back intermediate layer

Erector spinae (spinalis) origin

Broad tendon arising from: 1. Posterior part of iliac crest; 2. Posterior surface of sacrum; 3. Spinous processes of sacrum, lumbar and lower thoracic vertebrae

Erector spinae (spinalis) insertion

Spinalis (capitis, cervicis, thoracis) fibers run superiorly to spinous processes in the upper thoracic and cervical regions and to cranium

Erector spinae (longissimus) origin

Broad tendon arising from: 1. Posterior part of iliac crest; 2. Posterior surface of sacrum; 3. Spinous processes of sacrum, lumbar and lower thoracic vertebrae

Erector spinae (longissimus) insertion

Longissimus (capitis, cervicis, thoracis) fibers run superiorly to: 1. Ribs between tubercles and angles; 2. Transverse processes in thoracic and cervical regions; 3. Mastoid process of temporal bone

Erector spinae (iliocostalis) origin

Broad tendon arising from: 1. Posterior part of iliac crest; 2. Posterior surface of sacrum; 3. Spinous processes of sacrum, lumbar and lower thoracic vertebrae

Erector spinae (iliocostalis) insertion

Iliocostalis (cervicis, thoracis, lumborum) fibers run superiorly to: 1. Angles of lower ribs; 2. Transverse processes of cervical vertebrae

Erector spinae (spinalis) action,

1. Extension of spinal column; 2. Lateral flexion of spinal column (actions listed for the erector spinae group)

Erector spinae (longissimus) action,

1. Extension of spinal column; 2. Lateral flexion of spinal column (actions listed for the erector spinae group)

Erector spinae (iliocostalis) action,

1. Extension of spinal column; 2. Lateral flexion of spinal column (actions listed for the erector spinae group)

Erector spinae (spinalis) innervation

, Dorsal rami of spinal nerves of respective region

Erector spinae (longissimus) innervation,

Dorsal rami of spinal nerves of respective region

Erector spinae (iliocostalis) innervation,

Dorsal rami of spinal nerves of respective region