Deep Back and Suboccipital Triangle

Objectives: Describe the structure, attachments, function and support of: splenius capitus and cervicis erector spinae transversospinal group intersegmental group Describe the attachments, actions and support of the suboccipital muscles. Describe the boundaries, contents and relationships of the suboccipital triangle.

Thoracolumbar Fascia The thoracolumbar fascia: surrounds the deep muscles of the back superiorly, continuous with deep fascia of the neck “deep” to serratus posterior muscles medially, attaches to the spines of the vertebrae laterally, attaches to the transverse processes inferiorly, attaches to lower border of 12th rib and iliac crest Deep back muscles do not move limbs. They are intrinsic muscles, only move the vertebral column.

Thoracolumbar Fascia (trans. Section through trunk)

Deep Back Muscles and Innervation

Rotation of Vertebrae Rotation refers to the direction the body is moving.

Splenius Cervicis: Splenius Capitis: Attachments: Action: Innervation: Splenius= bandage (flat)

Splenius Cervicis & Capitis

Erector Spinae Spinalis Longissimus Iliocostalis Mnemonic: “ I Love Spaghetti”... Spinalis- attachment is spine to spine for spinalis muscles. Depending where muscles attach, get named specifically (i.e. spinalis thoracis)… Longissimus muscles-think transverse process. Starts at saccrum, attach at trans. Processes. Attaches in diff. regions, and named as such. Iliocostalis- comes off ileum and attaches to the ribs. Lumborum muscles attaches to the ribs in the lumbar region of the spine….thoracis muscles attach to the ribs in the thoracis region of the spine. No ribs in the cervical region…so no iliocostalis cervicis muscles.

Erector Spinae

(SBL = side bend to the left…Rr = rotated to the right side)… A 35-year-old male presents with the main complaint of lower back discomfort. Physical exam reveals that L1 – L4 are SBL and RR. Dysfunction of what muscle is most likely responsible for this finding? (SBL = side bend to the left…Rr = rotated to the right side)… (SBL = side bend to the left…Rr = rotated to the right side)…

Transversospinal Group Rotatores Multifidus Semispinalis

Transversospinal Group

Transversospinal Group

Intersegmental Muscles Interspinales: Intertransversarii:

Intersegmental Muscles Intertransversarii: in the thoracic region intertransversarii are modified to form the levator costarum

Suboccipital Muscles situated deep to semispinalis capitis Rectus capitis posterior major Rectus capitis posterior minor Obliquus capitis inferior Obliquus capitis superior

Contents of the Suboccipital Triangle

Contents of the Suboccipital Triangle Left side: note the Greater Occipital Nerve piercing the spinalis capitis nerve.

Greater occipital nerve (C2) runs through the semispinalis capitis muscle and underneath the inferior oblique muscle. Greater occipital nerve terminates over the scalp.