Iliocostalis

Authors

Affiliations

Nate Yomogida, B.S., SPT

Doctor of Physical Therapy

B.S. in Kinesiology

Chloë Kerstein, B.S., SPT

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Muscles of the Neck and Back¹

Reading list

• Thoracolumbar paraspinal muscles²
• Neuman³

Table 1: Iliocostalis muscles

Muscle	Origin	Insertion	Innervation	Action
Iliocostalis cervicis	Ribs 3-7	C4-C6 TP	Spinal nn. Posterior rami (lateral br.) C8 - L1	Bilateral: Extends spine Unilateral: Spine ipsilateral sidebend
Iliocostalis lumborum	Sacrum Iliac crest Thoracolumbar fascia (posterior layer)	Ribs 6-12 Upper lumbar TP Thoracolumbar fascia (posterior layer)	Spinal nn. Posterior rami (lateral br.) C8 - L1	Bilateral: Extends spine Unilateral: Spine ipsilateral sidebend
Iliocostalis thoracis	Ribs 7-12	Ribs 1-6	Spinal nn. Posterior rami (lateral br.) C8 - L1	Bilateral: Extends spine Unilateral: Spine ipsilateral sidebend

Iliocostalis Cervicis

Origin

3rd-7th ribs⁴

Insertion

C4-C6 TP⁴

Innervation

Spinal nn. C8-L1 (Post rami, lateral branches)⁴

Action

Iliocostalis Thoracis

Origin

7-12th ribs⁴

Insertion

1st-6th ribs⁴

Innervation

Spinal nn. C8-L1 (Post rami, lateral branches)⁴

Action

Iliocostalis Lumborum

Origin

Sacrum, iliac crest, lumbar vertebrae SP; lower thoracic vertebrae TP⁴

Insertion

6-12th ribs, thoracolumbar fascia (posterior layer), upper lumbar vertebrae (TP)⁴

Innervation

Spinal nn. C8-L1 (Post rami, lateral branches)⁴

Action

• Bilateral: Extends spine⁴
• Unilateral: I/L spine lat-flexion⁴

Muscle groups

Iliocostalis is part of the Intermediate intrinsic back muscles (erector spinae)

Palpation

Clinical significance

1.

Betts JG, Blaker W. Anatomy and Physiology. 2nd ed. OpenStax; 2022. https://openstax.org/details/books/anatomy-and-physiology-2e/?Book%20details

2.

Donnelly JM, Simons DG, eds. Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Third edition. Wolters Kluwer Health; 2019.

3.

Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.

4.

Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.