Piriformis Muscle

Authors
Affiliations

Doctor of Physical Therapy

B.S. in Kinesiology

Doctor of Physical Therapy

B.A. in Neuroscience

Figure 1: Hip and Thigh Muscles
Figure 2: Muscles of the gluteal and posterior femoral region
Reading list
  • ch52 Pelvic floor muscles
  • Ch57 piriformis, obturator internus, gemellus, obturator externus, quadratus femoris muscles
  • Neuman
  • MMT
Table 1
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Origin

Anterior surface of sacrum from the 2nd-4th sacral segments.

Path

After its origin the piriformis runs through the greater sciatic foramen before reaching its insertion on the greater trochanter.

Insertion

Apex of the greater trochanter of the femur.

Innervation

Direct branches from sacral plexus S1 and S2.

Action

According to Gilroy, the piriformis functions in External rotation, abduction, extension and stabilization of the hip joint.

This is only partly true.

At ≥60° hip flexion, the piriformis produces an internal rotation torque.

Neutral

  • ER
  • Flexion
  • Abduction

60° Flexion

  • IR
  • Extension
  • Abductor

Anatomy

The Sciatic n. runs superficial to all of the deep external rotators except for the piriformis. The sciatic nerve can either runs deep to the piriformis and can exit inferiorly, through the piriformis muscle belly, or superior to the piriformis. As a result, overactivation of the piriformis can lead to neurogenic pain and symptoms and is termed Piriformis syndrome

Palpation

  1. Place the patient in prone.
  2. Palpate the: coccyx, PSIS, and greater trochanter.
  3. The coccyx to the PSIS is the superior and inferior bounds of the piriformis origin and the greater trochanter is the insertion.
  4. Bisect the coccyx and PSIS and place a finger there.
  5. Place your fingers along the imaginary line from the bisection to the greater trochanter.
  6. Work through the superficial gluteus maximus to palpate the slender piriformis muscle belly.
  7. Strum across the piriformis muscle belly to palpate its location.
Caution

The sciatic nerve runs through this area, so be mindful of this when palpating.

Active palpation

One can bend the patient’s knee and ask the patient to perform isometric contractions against gentle resistance to better palpate the piriformis. The gluteus maximus may be recruited during this process, but the piriformis should be more evident.

Pathologies

Piriformis tendinitis

“Tenderness to deep palpation near the hook of the greater trochanter. Pain reproduced by piriformis stretch”

Piriformis Syndrome

The Sciatic n. runs superficial to all of the deep external rotators except for the piriformis. The sciatic nerve can either runs deep to the piriformis and can exit inferiorly, through the piriformis muscle belly, or superior to the piriformis. As a result, overactivation of the piriformis can lead to neurogenic pain and symptoms and is termed Piriformis syndrome

Active Release Technique (ART)

Active release technique for piriformis by Dr. Nick Perkins

  • Patient in contralateral sidelying
  • STM to piriformis
  • move from hip IR/ABD/Ext into hip ER/Adduction/Flexion

References

1.
Betts JG, Blaker W. Openstax 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.
Jones B. B Project Foundations. b Project; 2025.
8.
Biel A. Trail Guide to the Body: A Hands-on Guide to Locating Muscles, Bones, and More. 6th ed. Books of Discovery; 2019.
9.
Dutton M. Dutton’s Orthopaedic Examination, Evaluation, and Intervention. 5th ed. McGraw Hill Education; 2020.
10.
Perkins N. Stretch Affect Clinical Internship. Published online 10-14-24.

Citation

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