Pyramidalis Muscle

Anterior abdominal wall 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

Reading list

• Abdominal muscles¹
• Neuman²

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Muscle	Origin	Insertion	Innervation	Action
Pyramidalis			T12	Tenses linea alba

Origin

Pubis (anterior to rectus abdominis)³.

Insertion

The pyramidalis runs within the rectus sheath to insert on the linea alba³.

Innervation

The pyramidalis is innervated by the Subcostal n. with origins from the T12³.

Action

In a literal sense the linea alba “tenses” the linea alba^3,4.

Overview

The muscle is only present in 80% of the population⁴ and can even be absent in one or both sides⁴.

Note

If the pyramidalis is absent, the rectus abdominis will adjust and increase its size.

References

1.

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

2.

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

3.

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

4.

Jones B. B Project Foundations. b Project; 2025.