pyramidalis muscle (anatomy)
Last reviewed 01/2018
Pyramidalis is a small muscle of the anterior abdominal wall. It arises from the pubic crest and passes superiorly to insert into the linea alba. It lies anterior to rectus abdominis.
It is innervated by the subcostal nerve (T12).
Pyramidalis acts to strengthen the inferior part of the rectus sheath. It is absent in approximately 20% of the population.