Psoas Major Muscle

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 Abdomen

Muscles of the Iliac and Anterior femoral regions2

Muscles of the Iliac and Anterior femoral regions
Figure 2: Hip and Thigh Muscles
Reading list
  • Psoas major, psoas minor, iliacus muscles
  • Neuman
  • MMT
Muscle Origin Insertion Innervation Action
Psoas Major T12-L4 and associated IV discs
L1-L5 TP		 Lesser Trochanter Lumbar Plexus Direct Br.
L1 - L3		 Hip: Flexion, ER
L/S (unilateral contraction with femur fixed): I/L spine sidebend
L/S (bilateral contraction): Raises trunk from supine position

Origin

  • Superficial: T12–L4 and associated intervertebral disks (lateral surfaces)
  • Deep: L1–L5 vertebrae (TPs)
  • The Psoas Major has fibrous attachments from the anterior TP of the lumbar spine as well as the anteromedial aspect of the lumbar IVD, except for L5/S1 disc

Insertion

Femur (lesser trochanter)

Innervation

Lumbar plexus Direct Br. (L1, L2, L3)

Action

Hip joint: flexion and external rotation Lumbar spine: unilateral contraction (with the femur fixed) flexes the trunk laterally to the same side; bilateral contraction raises the trunk from the supine position

Overview

Stretches

References

1.
Betts JG, Blaker W. Anatomy and Physiology. 2nd ed. OpenStax; 2022. https://openstax.org/details/books/anatomy-and-physiology-2e/?Book%20details
2.
Gray H. Anatomy of the Human Body. 20th ed. (Lewis WH, ed.). Lea & Febiger; 1918. https://www.bartleby.com/107/
3.
Donnelly JM, Simons DG, eds. Travell, Simons & Simons’ Myofascial Pain and Dysfunction: The Trigger Point Manual. Third edition. Wolters Kluwer Health; 2019.
4.
Neumann DA, Kelly ER, Kiefer CL, Martens K, Grosz CM. Kinesiology of the Musculoskeletal System: Foundations for Rehabilitation. 3rd ed. Elsevier; 2017.
5.
Weinstock D. NeuroKinetic Therapy: An Innovative Approach to Manual Muscle Testing. North Atlantic Books; 2010.
6.
Gilroy AM, MacPherson BR, Wikenheiser JC, Voll MM, Wesker K, Schünke M, eds. Atlas of Anatomy. 4th ed. Thieme; 2020.
7.
Bogduk N, Pearcy M, Hadfield G. Anatomy and biomechanics of psoas major. Clinical Biomechanics. 1992;7(2):109-119. doi:10.1016/0268-0033(92)90024-X

Citation

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