Iliocostalis Lumborum

Description[edit | edit source]

Iliocostalis lumborum is part of the erector spinae muscle group which includes iliocostalis, longissimus, and spinalis. The muscle bulk formed by this muscle group can be felt running parallel to the spine over the transverse processes of each vertebra. These muscles are vital for allowing free movement of the spine.

Iliocostalis lumborum bottom R, iliocostalis dorsi at centre

Iliocostalis is a dorsal muscle situated deep to the fleshy section of serratus posterior inferior muscle. Iliocostalis lumborum is the lower (lumbar) portion of that muscle.

  • Injury to iliocostalis lumborum may be indicated by pain concentrated in the lower back or pain in the buttocks. Common daily activities may cause injury to the muscle including lifting a heavy object, rotating while lifting, or even sitting immobile for extended periods of time.
  • If there is a significant discrepancy between the strength of the abdominal muscles and the lumbar muscles of the back, it may result in a condition known as lumbar hyperlordosis. This condition can be successfully reversed through targeted stretches and exercises aimed at strengthening the deficient muscles.[1]

Anatomy[edit | edit source]

Origin[edit | edit source]

  • Anterior surface of a broad and thick tendon attached to the medial crest of the sacrum,
  • Posterior part of the medial lip of iliac crest, supra-spinous ligament and the lateral crest of sacrum[2].

Insertion[edit | edit source]

By tendons into inferior borders of the angles of the lower 6 or 7 ribs [2]

Nerve Supply[edit | edit source]

Dorsal rami of thoracic and lumbar spinal nerves (T7 to L3)[3]

Blood Supply[edit | edit source]

Dorsal branches of the lumbar arteries from the aorta. Dorsal branches of the lateral sacral artery from the internal iliac artery.[3]

Muscle Fibre[edit | edit source]

Characterised by Type 1 muscle fibre, indicating the tonic holding and stabilisation function.[4]

Muscles of the back erector spinae group

Action[edit | edit source]

  • Extension of Spine: Acting bilaterally, extension and hyperextension of the spine.
  • Laterally flexes the spine when acting unilaterally[5]
  • Respiration: It assists as an accessory muscle of expiration, due to its insertion on the ribs[6]
  • Stabilization of Spine: Iliocostalis lumborum along with multifidus contribute to support and control the orientation of lumbar spine.[4]

Clinical Relevance:[edit | edit source]

Assessment[edit | edit source]

It is impossible to isolate one part of the erector spinae muscles for assessment therefore assessing the erector spinae in terms of movement patterns is more relevant in clinical practice.

See lumbar spine

Length

  • Bilateral contracture of low back muscles results in lordosis.
  • Unilateral contracture results in scoliosis with convexity to the opposite side.

Treatment[edit | edit source]

Strengthening exercises:[edit | edit source]

1. Prone extension exercise[8]:

a) In prone lying, have the patient tuck in the chin and lift the head, thorax of the plinth.

b) To progress further, the patient can vary the arm position. Resistance can be added by using hand-held weights.

c) Patient can further progress by lifting one leg off the mat alternately, and progress to both legs simultaneously.

d) Further progression can be made - spine extension with both upper limbs and lower limbs lifted off the mat.

2. Prone exercises on a stability ball.

3. Plank and quadruped exercises to develop control and strength in spinal extensors.

4.Postural exercises.

Stretching exercises:[edit | edit source]

Trunk lateral bending exercises to the opposite side of tightness and flexion exercises help in stretching the tight muscles.


References[edit | edit source]

  1. rehab my patients Iliocostalis Lumborum Available: https://www.rehabmypatient.com/lumbar-spine/iliocostalis-lumborum (accessed 1.12.2021)
  2. 2.0 2.1 Muscle Testing and Function;4th Edition; Kendall, McCreary, Provance; Page No.138.
  3. 3.0 3.1 Iliocostalis muscle [Internet]. Kenhub. 2021 [cited 1 December 2021]. Available from: https://www.kenhub.com/en/library/anatomy/iliocostalis-muscle
  4. 4.0 4.1 Therapeutic Exercise for Spine Segmental Stabilization in Low Back Pain; Richardson, Jull, Hodges, Hides; Scientific Basis; Page No.24.
  5. Wheeless Textbook of Orthopaedics; Iliocostalis Lumborum http://www.wheelessonline.com/ortho/iliocostalis_lumborum_1 (accessed on 2.07.18)
  6. Muscles Testing and Function;4th Edition; Kendall, McCreary, Provance; Accessory Muscles of Respiration, Page No.330.
  7. 7.0 7.1 Roldan CJ, Huh BK. Iliocostalis thoracis-lumborum myofascial pain: Reviewing a subgroup of a prospective, randomized, blinded trial. A challenging diagnosis with clinical implications. Pain physician. 2016 Aug 1;19(6):363-72.
  8. Therapeutic Exercise; Third Edition; Kisner & Colby; The Spine: Subacute, Chronic, and Postural Problems; Page No.562