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Muscles: Piriformis.

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Anatomy & Physiology: Muscles—Piriformis.

Structure.

  • Origin: anterior surface of sacrum.
  • Insertion: greater trochanter of femur.
  • Of deep rotator group.

Function.

  • Concentric action: accelerates abduction, and external/lateral rotation.
  • Reverse mover action: contralateral and ipsilateral rotation of the pelvis.
  • Eccentric action: decelerates hip flexion, adduction and internal rotation.
  • Isometric action: stabilization hip and sacroiliac joints.
  • Innervation: sacral spinal nerves S1 (mainly) and S2.
  • Arterial supply: superior and inferior gluteal arteries.

Clinical Significance.

More.

References

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

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.