Pyramidalis is a paired anterior triangular abdominal muscle with rectus abdominis that contributes to form the anterior abdominal wall. It's absent in 20% of the population and has a less significant role.
It arises from symphysis pubic and pubic crest
It decreases in size as it ascends and inserts medially to linea alba as a pointed apex.
It is innervated by subcostal nerve T12
The main arterial supply from the inferior epigastric supply and the deep circumflex iliac artery to a lesser extent.
When they contract tense the linea alba, contract with other abdominal muscle to increase positive abdominal pressure.
It is used as a surgical landmark as in cesarean section to define the midline of the linea alba. used as a source of muscle stem cell in the treatment of post-prostatectomy stress urinary incontinence
Pyramidalis attached directly to the adductor longus via anterior pubic ligament forming Pyramidalis anterior pubic ligament adductor longus complex PLAC and that will help in the treatment of proximal adductor avulsion.
- Kenhub - Learn Human Anatomy. Pyramidalis Muscle Overview and Function- Human Anatomy | Kenhub. Available from: http://www.youtube.com/watch?v=NR037gEOsWg[last accessed 17/5/2020]
- Das SS, Saluja S, Vasudeva N. Biometrics of Pyramidalis Muscle and its Clinical Importance. Journal of clinical and diagnostic research: JCDR. 2017 Feb;11(2):AC05.
- Sumino Y, Hirata Y, Hanada M, Akita Y, Sato F, Mimata H. Long‐term cryopreservation of pyramidalis muscle specimens as a source of striated muscle stem cells for treatment of post‐prostatectomy stress urinary incontinence. The Prostate. 2011 Aug 1;71(11):1225-30.
- Schilders E, Bharam S, Golan E, Dimitrakopoulou A, Mitchell A, Spaepen M, Beggs C, Cooke C, Holmich P. The pyramidalis–anterior pubic ligament–adductor longus complex (PLAC) and its role with adductor injuries: a new anatomical concept. Knee Surgery, Sports Traumatology, Arthroscopy. 2017 Dec 1;25(12):3969-77.