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Muscles: Longissimus.

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Anatomy & Physiology: Muscles—Longissimus, of erector spinae group.

Structure.

  • Longissimus Capitis
    • Origin: transverse processes of T1-T5; articular processes of C4-C7.
    • Insertion: mastoid process of temporal bone.
  • Longissimus Cervicus
    • Origin: transverse processes of T1-T5.
    • Insertion: transverse processes of C2-C6.
  • Longissimus Thoracis
    • Origin: medial iliac crest, posterior sacrum, transverse processes and spinous processes of L1-L5.
    • Insertion: transverse processes of all thoracic vertebrae and lower nine ribs.

Function.

  • Concentric action: trunk, neck, and head extension at spinal joints; lateral flexion of trunk, neck, and head at spinal joints. Lesser: ipsilateral rotation of trunk, head, and neck.
  • Reverse mover action: anterior tilt of pelvis at the LS joint; lower spine extension. Lesser: ipsilateral elevation of pelvis and lateral flexion of lower spine; contralateral rotation of the pelvis and lower spine.
  • Eccentric action: controls/restrains/slows flexion, contralateral lateral flexion, and contralateral rotation of trunk, neck, and head; controls/restrains/slows posterior tilt, ipsilateral rotation, and ipsilateral depression of pelvis.
  • Isometric action: stabilization of the spine, ribs, and SI joint.
  • Innervation: middle and inferior cervical and spinal nerves.
  • Arterial supply: dorsal branches of posterior intercostal and lumbar arteries.

Clinical Significance.

 

References

Biel, A. (2015). Trail guide to the body: A hands-on guide to locating muscles, bones and more.

Cedars-Sinai. (2018). Vertebrae of the spine. Retrieved from https://www.cedars-sinai.org/health-library/diseases-and-conditions/v/vertebrae-of-the-spine.html

Clark, M., Lucett, S., Sutton, B. G., & National Academy of Sports Medicine. (2014). NASM essentials of corrective exercise training. Burlington, MA: Jones & Bartlett Learning.

Jenkins, G., & Tortora, G. J. (2012). Anatomy and Physiology: From Science to Life, 3rd Edition International Stu. John Wiley & Sons.

Muscolino, J. E. (2017). The muscular system manual: The skeletal muscles of the human body.