Longissimus

Description

• 
  Longissimus muscle
• 
  The erector spinae muscles
• 
  Deep spinal muscles including semispinalis, multifidus, spinalis, longissimus, iliocostalis
• 
  Anatomy of some of the back muscles

Longissimus thoracic lumborum muscle and iliocostalis lumborum muscle anatomy

Name

• Longissimus

General

• Intermediate portion of Erector Spinae
• Extends from lumbar spine to posterior head

Subsegments

• Longissimus Lumborum
• Longissimus Thoracis
• Longissimus Cervicis (Transversalis Cervicis)
• Longissimus Capitis (Trachelomastoid)

Origin

• Transverse processes of lumbar and thoracic vertebrae
• Accessory processes of lumbar vertebrae
• Anterior lumbodorsal fascia
• Articular processes of C4-C7

Insertion

• Transverse processes of thoracic vertebrae
• Ribs 3-12 (between tubercles and angles)
• Transverse processes (posterior tubercles) of vertebrae C2-C6
• Mastoid process (posterior margin)

Actions

• Bilateral: Extension of trunk, cervical spine, and head
• Unilateral: Sidebending of trunk, cervical spine, and head to same side
• Depression of ribs (accessory muscle of expiration)

Vascular Supply

• Deep Cervical Artery
• Posterior Intercostal Arteries
• Subcostal Arteries
• Lumbar Arteries
• Lateral Sacral Artery

Innervation

• Spinal nerves C1-S1 (Dorsal Rami)

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Clinical Significance

• Mechanical Back Pain

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See Also

• Physical Exam Neck
• Neck Anatomy (Main)
• Neck Pain (Main)

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